From ee6c5eb0c78c18254cc240987e75024f385e8004 Mon Sep 17 00:00:00 2001
From: armandobelardo <armandoubelardo@gmail.com>
Date: Tue, 1 Oct 2024 15:19:32 -0400
Subject: [PATCH 1/9] feat(seed): introduce scripts to generators so fern bot
 can build the SDKs

---
 packages/cli/cli/package.json                 |  4 +-
 packages/cli/configuration/package.json       |  4 +-
 packages/core/package.json                    |  4 +-
 packages/seed/fern/definition/config.yml      | 86 +++++++++++--------
 packages/seed/package.json                    |  4 +-
 .../commands/register/registerGenerator.ts    |  3 +-
 .../config/types/ArtifactMetadata.ts          | 15 ++++
 .../config/types/DockerScriptConfig.ts        |  9 ++
 .../types/{ScriptConfig.ts => Script.ts}      |  3 +-
 .../types/SeedWorkspaceConfiguration.ts       |  3 +-
 .../api/resources/config/types/index.ts       |  4 +-
 pnpm-lock.yaml                                | 39 +++------
 seed/fastapi/seed.yml                         | 11 +++
 seed/go-fiber/seed.yml                        | 14 ++-
 seed/go-model/seed.yml                        | 14 ++-
 seed/go-sdk/seed.yml                          | 14 ++-
 seed/java-model/seed.yml                      |  9 +-
 seed/java-sdk/seed.yml                        | 15 ++--
 seed/pydantic/seed.yml                        | 11 +++
 seed/python-sdk/seed.yml                      | 38 +++++---
 seed/ruby-model/seed.yml                      |  7 +-
 seed/ruby-sdk/seed.yml                        | 13 ++-
 seed/ts-express/seed.yml                      | 27 +++---
 23 files changed, 238 insertions(+), 113 deletions(-)
 create mode 100644 packages/seed/src/config/api/resources/config/types/ArtifactMetadata.ts
 create mode 100644 packages/seed/src/config/api/resources/config/types/DockerScriptConfig.ts
 rename packages/seed/src/config/api/resources/config/types/{ScriptConfig.ts => Script.ts} (65%)

diff --git a/packages/cli/cli/package.json b/packages/cli/cli/package.json
index 1066f0cf110..fa69594a205 100644
--- a/packages/cli/cli/package.json
+++ b/packages/cli/cli/package.json
@@ -74,7 +74,7 @@
     "@fern-api/fern-definition-formatter": "workspace:*",
     "@fern-api/cli-migrations": "workspace:*",
     "@fern-api/fern-definition-schema": "workspace:*",
-    "@fern-fern/generators-sdk": "0.109.0-21be2e5be",
+    "@fern-fern/generators-sdk": "0.114.0-5745f9e74",
     "@fern-fern/fiddle-sdk": "0.0.584",
     "@types/get-port": "^4.2.0",
     "ansi-escapes": "^5.0.0",
@@ -115,4 +115,4 @@
     "prettier": "^2.7.1",
     "typescript": "4.6.4"
   }
-}
\ No newline at end of file
+}
diff --git a/packages/cli/configuration/package.json b/packages/cli/configuration/package.json
index dec9724c9af..62afe1df14c 100644
--- a/packages/cli/configuration/package.json
+++ b/packages/cli/configuration/package.json
@@ -35,7 +35,7 @@
     "@fern-api/fern-definition-schema": "workspace:*",
     "@fern-fern/fdr-cjs-sdk": "0.108.0-dcb0f740c",
     "@fern-fern/fiddle-sdk": "0.0.584",
-    "@fern-fern/generators-sdk": "0.109.0-21be2e5be",
+    "@fern-fern/generators-sdk": "0.114.0-5745f9e74",
     "find-up": "^6.3.0",
     "js-yaml": "^4.1.0",
     "lodash-es": "^4.17.21",
@@ -57,4 +57,4 @@
     "typescript": "4.6.4",
     "vitest": "^2.0.5"
   }
-}
\ No newline at end of file
+}
diff --git a/packages/core/package.json b/packages/core/package.json
index 5cc808d57cd..cccf57baf12 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -29,7 +29,7 @@
   },
   "dependencies": {
     "@fern-fern/fdr-cjs-sdk": "0.108.0-dcb0f740c",
-    "@fern-fern/generators-sdk": "0.107.0-00fe26566",
+    "@fern-fern/generators-sdk": "0.114.0-5745f9e74",
     "@fern-api/venus-api-sdk": "0.0.38",
     "@fern-fern/fdr-test-sdk": "^0.0.5297",
     "@fern-fern/fiddle-sdk": "0.0.584"
@@ -44,4 +44,4 @@
     "prettier": "^2.7.1",
     "typescript": "4.6.4"
   }
-}
\ No newline at end of file
+}
diff --git a/packages/seed/fern/definition/config.yml b/packages/seed/fern/definition/config.yml
index ac997af6853..0a9fbbd6a04 100644
--- a/packages/seed/fern/definition/config.yml
+++ b/packages/seed/fern/definition/config.yml
@@ -6,9 +6,9 @@ types:
       publishGa: PublishCommand
       publishRc: PublishCommand
       publishDev: PublishCommand
-      changelogLocation: 
+      changelogLocation:
         type: optional<string>
-        docs: | 
+        docs: |
           The location of the changelog file, the schema of which must follow FDR's `GeneratorReleaseRequest` object.
 
   SeedWorkspaceConfiguration:
@@ -18,9 +18,9 @@ types:
       irVersion: string
       test: TestConfiguration
       publish: PublishConfiguration
-      changelogLocation: 
+      changelogLocation:
         type: optional<string>
-        docs: | 
+        docs: |
           The location of the changelog file, the schema of which must follow FDR's `GeneratorReleaseRequest` object.
 
       language: optional<Language>
@@ -28,20 +28,22 @@ types:
       defaultOutputMode: OutputMode
       generatorType: GeneratorType
 
-      customFixtureConfig: 
+      artifactMetadata: optional<ArtifactMetadata>
+
+      customFixtureConfig:
         type: optional<FixtureConfigurations>
         docs: |
           Configuration that will be used for any custom fixture specified by --custom-fixture
       fixtures:
         type: optional<map<string, list<FixtureConfigurations>>>
-      scripts: optional<list<ScriptConfig>>
-      allowedFailures: 
+      scripts: optional<list<DockerScriptConfig>>
+      allowedFailures:
         type: optional<list<string>>
-        docs: | 
-          List any fixtures that are okay to fail. For normal fixtures 
+        docs: |
+          List any fixtures that are okay to fail. For normal fixtures
           just list the fixture name. For configured fixture list {fixture}:{outputFolder}.
       features: optional<features.GeneratorFeatures>
-  
+
   PublishDockerConfiguration:
     properties:
       context: string
@@ -63,18 +65,18 @@ types:
       Commands can be multi-line, we'll run them all!
     properties:
       workingDirectory: optional<string>
-      versionSubstitution: 
+      versionSubstitution:
         type: optional<string>
-        docs: | 
+        docs: |
           The string to substitute for the version in the command. ex. `"$VERSION"`
       command: DockerCommand
 
   PublishConfiguration:
     discriminated: false
-    union: 
+    union:
       - PublishDocker
       - PublishCommand
-  
+
   TestDockerConfiguration:
     properties:
       image: string
@@ -85,38 +87,50 @@ types:
       docker: TestDockerConfiguration
       local: optional<LocalBuildInfo>
 
-  LocalBuildInfo: 
-    properties: 
-      workingDirectory: 
+  LocalBuildInfo:
+    properties:
+      workingDirectory:
         type: string
-        docs: | 
-          The working directory for the generator. 
-      buildCommand: 
+        docs: |
+          The working directory for the generator.
+      buildCommand:
         type: list<string>
-        docs: | 
-          The command to build the generator locally. 
-          `yarn workspace @fern-api/openapi-generator build` for example. 
+        docs: |
+          The command to build the generator locally.
+          `yarn workspace @fern-api/openapi-generator build` for example.
       runCommand:
         type: string
-        docs: | 
-          The command to run the generator locally. 
+        docs: |
+          The command to run the generator locally.
           `node generators/openapi/dist/cli.cjs` for example.
-      env: 
+      env:
         type: optional<map<string, string>>
-        docs: | 
+        docs: |
           Environment variables to set when running the generator locally.
 
-  DockerCommand: 
+  ArtifactMetadata:
+    docs: Metadata relating to the artifact produced by this generator
+    properties:
+      preInstallScript: optional<Script>
+      installScript: optional<Script>
+      compileScript: optional<Script>
+      testScript: optional<Script>
+
+  DockerCommand:
     discriminated: false
-    union: 
+    union:
       - string
       - list<string>
 
-  ScriptConfig:
+  Script:
     properties:
-      docker: string
       commands: list<string>
 
+  DockerScriptConfig:
+    extends: Script
+    properties:
+      docker: string
+
   Language:
     enum:
       - python
@@ -144,7 +158,7 @@ types:
       audiences: optional<list<string>>
       outputFolder: string
       outputVersion: optional<string>
-      outputMode: 
+      outputMode:
         type: optional<OutputMode>
         docs: Overrides the default output mode
 
@@ -157,7 +171,7 @@ types:
 
   ReadmeEndpoint:
     discriminated: false
-    union: 
+    union:
       - string
       - ReadmeEndpointObject
 
@@ -166,9 +180,9 @@ types:
       method: string
       path: string
       stream: optional<boolean>
-  
-  OutputMode: 
-    enum: 
+
+  OutputMode:
+    enum:
       - github
       - local_files
       - publish
diff --git a/packages/seed/package.json b/packages/seed/package.json
index fa4bbb47b13..6cc8c56b382 100644
--- a/packages/seed/package.json
+++ b/packages/seed/package.json
@@ -48,7 +48,7 @@
     "@fern-api/workspace-loader": "workspace:*",
     "@fern-fern/fiddle-sdk": "0.0.584",
     "@fern-fern/generator-exec-sdk": "^0.0.898",
-    "@fern-fern/generators-sdk": "0.109.0-21be2e5be",
+    "@fern-fern/generators-sdk": "0.114.0-5745f9e74",
     "@types/pretty-ms": "^5.0.1",
     "chalk": "^5.3.0",
     "console-table-printer": "^2.12.0",
@@ -79,4 +79,4 @@
     "typescript": "4.6.4",
     "vitest": "^2.0.5"
   }
-}
\ No newline at end of file
+}
diff --git a/packages/seed/src/commands/register/registerGenerator.ts b/packages/seed/src/commands/register/registerGenerator.ts
index 67200360463..34c2a6f27ed 100644
--- a/packages/seed/src/commands/register/registerGenerator.ts
+++ b/packages/seed/src/commands/register/registerGenerator.ts
@@ -25,7 +25,8 @@ export async function registerGenerator({
         displayName: generatorConfig.displayName,
         generatorType: convertGeneratorType(generatorConfig.generatorType),
         generatorLanguage: generatorConfig.language,
-        dockerImage: generatorConfig.image
+        dockerImage: generatorConfig.image,
+        scripts: generatorConfig.artifactMetadata
     });
 
     // Register generator versions
diff --git a/packages/seed/src/config/api/resources/config/types/ArtifactMetadata.ts b/packages/seed/src/config/api/resources/config/types/ArtifactMetadata.ts
new file mode 100644
index 00000000000..6ab8b456375
--- /dev/null
+++ b/packages/seed/src/config/api/resources/config/types/ArtifactMetadata.ts
@@ -0,0 +1,15 @@
+/**
+ * This file was auto-generated by Fern from our API Definition.
+ */
+
+import * as FernSeedConfig from "../../..";
+
+/**
+ * Metadata relating to the artifact produced by this generator
+ */
+export interface ArtifactMetadata {
+    preInstallScript?: FernSeedConfig.Script;
+    installScript?: FernSeedConfig.Script;
+    compileScript?: FernSeedConfig.Script;
+    testScript?: FernSeedConfig.Script;
+}
diff --git a/packages/seed/src/config/api/resources/config/types/DockerScriptConfig.ts b/packages/seed/src/config/api/resources/config/types/DockerScriptConfig.ts
new file mode 100644
index 00000000000..7f9efc771d9
--- /dev/null
+++ b/packages/seed/src/config/api/resources/config/types/DockerScriptConfig.ts
@@ -0,0 +1,9 @@
+/**
+ * This file was auto-generated by Fern from our API Definition.
+ */
+
+import * as FernSeedConfig from "../../..";
+
+export interface DockerScriptConfig extends FernSeedConfig.Script {
+    docker: string;
+}
diff --git a/packages/seed/src/config/api/resources/config/types/ScriptConfig.ts b/packages/seed/src/config/api/resources/config/types/Script.ts
similarity index 65%
rename from packages/seed/src/config/api/resources/config/types/ScriptConfig.ts
rename to packages/seed/src/config/api/resources/config/types/Script.ts
index 2d8db19b4b7..159de7e1430 100644
--- a/packages/seed/src/config/api/resources/config/types/ScriptConfig.ts
+++ b/packages/seed/src/config/api/resources/config/types/Script.ts
@@ -2,7 +2,6 @@
  * This file was auto-generated by Fern from our API Definition.
  */
 
-export interface ScriptConfig {
-    docker: string;
+export interface Script {
     commands: string[];
 }
diff --git a/packages/seed/src/config/api/resources/config/types/SeedWorkspaceConfiguration.ts b/packages/seed/src/config/api/resources/config/types/SeedWorkspaceConfiguration.ts
index e4cbe52e326..c0d5603c50d 100644
--- a/packages/seed/src/config/api/resources/config/types/SeedWorkspaceConfiguration.ts
+++ b/packages/seed/src/config/api/resources/config/types/SeedWorkspaceConfiguration.ts
@@ -16,10 +16,11 @@ export interface SeedWorkspaceConfiguration {
     defaultCustomConfig?: Record<string, unknown>;
     defaultOutputMode: FernSeedConfig.OutputMode;
     generatorType: FernSeedConfig.GeneratorType;
+    artifactMetadata?: FernSeedConfig.ArtifactMetadata;
     /** Configuration that will be used for any custom fixture specified by --custom-fixture */
     customFixtureConfig?: FernSeedConfig.FixtureConfigurations;
     fixtures?: Record<string, FernSeedConfig.FixtureConfigurations[]>;
-    scripts?: FernSeedConfig.ScriptConfig[];
+    scripts?: FernSeedConfig.DockerScriptConfig[];
     /**
      * List any fixtures that are okay to fail. For normal fixtures
      * just list the fixture name. For configured fixture list {fixture}:{outputFolder}.
diff --git a/packages/seed/src/config/api/resources/config/types/index.ts b/packages/seed/src/config/api/resources/config/types/index.ts
index d480c6c22e4..d60301c91fe 100644
--- a/packages/seed/src/config/api/resources/config/types/index.ts
+++ b/packages/seed/src/config/api/resources/config/types/index.ts
@@ -7,8 +7,10 @@ export * from "./PublishConfiguration";
 export * from "./TestDockerConfiguration";
 export * from "./TestConfiguration";
 export * from "./LocalBuildInfo";
+export * from "./ArtifactMetadata";
 export * from "./DockerCommand";
-export * from "./ScriptConfig";
+export * from "./Script";
+export * from "./DockerScriptConfig";
 export * from "./Language";
 export * from "./GeneratorType";
 export * from "./FixtureConfigurations";
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 5b02cd8e0f1..c7719c1701f 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -3137,8 +3137,8 @@ importers:
         specifier: 0.0.584
         version: 0.0.584
       '@fern-fern/generators-sdk':
-        specifier: 0.109.0-21be2e5be
-        version: 0.109.0-21be2e5be
+        specifier: 0.114.0-5745f9e74
+        version: 0.114.0-5745f9e74
       '@types/get-port':
         specifier: ^4.2.0
         version: 4.2.0
@@ -3333,6 +3333,8 @@ importers:
 
   packages/cli/cli/dist/dev: {}
 
+  packages/cli/cli/dist/prod: {}
+
   packages/cli/configuration:
     dependencies:
       '@fern-api/core-utils':
@@ -3354,8 +3356,8 @@ importers:
         specifier: 0.0.584
         version: 0.0.584
       '@fern-fern/generators-sdk':
-        specifier: 0.109.0-21be2e5be
-        version: 0.109.0-21be2e5be
+        specifier: 0.114.0-5745f9e74
+        version: 0.114.0-5745f9e74
       find-up:
         specifier: ^6.3.0
         version: 6.3.0
@@ -5741,8 +5743,8 @@ importers:
         specifier: 0.0.584
         version: 0.0.584
       '@fern-fern/generators-sdk':
-        specifier: 0.107.0-00fe26566
-        version: 0.107.0-00fe26566
+        specifier: 0.114.0-5745f9e74
+        version: 0.114.0-5745f9e74
     devDependencies:
       '@types/jest':
         specifier: ^29.5.12
@@ -5910,8 +5912,8 @@ importers:
         specifier: ^0.0.898
         version: 0.0.898
       '@fern-fern/generators-sdk':
-        specifier: 0.109.0-21be2e5be
-        version: 0.109.0-21be2e5be
+        specifier: 0.114.0-5745f9e74
+        version: 0.114.0-5745f9e74
       '@types/pretty-ms':
         specifier: ^5.0.1
         version: 5.0.1
@@ -7044,11 +7046,8 @@ packages:
   '@fern-fern/generator-exec-sdk@0.0.898':
     resolution: {integrity: sha512-VQYn32CkAd437deesaGk4LKikbVptxrWINAwUwiAUWOy77LelX1zWNKihjU2XDgIPv3VXK07aJwoPR5BDYD46Q==}
 
-  '@fern-fern/generators-sdk@0.107.0-00fe26566':
-    resolution: {integrity: sha512-fwk1xrv3wTO/6kJztIwO8Zz/thkRxIMLjYCtHelfbtbYNH9ZZr+yWDiCZGFBOOu7m8tuEZjaoOYOR3wiqmeivQ==}
-
-  '@fern-fern/generators-sdk@0.109.0-21be2e5be':
-    resolution: {integrity: sha512-McFSFWNqfZBC7E0gUQfhj45tTl8Eu+6bahqD6FHf0fQm+TXI/oQf8mhPJw/TVqzAGxP/2kOzSYNqkDg1DwkIFQ==}
+  '@fern-fern/generators-sdk@0.114.0-5745f9e74':
+    resolution: {integrity: sha512-FG7SU7ul1Q6EELAPsixGvbq8VP4Xjl42cd1VmLBlYXds5EtYxG/SZCu2QLsGgPMrkCFJ6V6VQgzXFTU3RoYR9A==}
 
   '@fern-fern/ir-sdk@39.0.0':
     resolution: {integrity: sha512-cx8g0hX3gS/JveQPKanSWAyhM8SGhVOiQEcovqmcF/j9wvpjO8FXXNNI1+ZR1Wdmkcggx9UIqXDbS7jzefh6Rw==}
@@ -14199,24 +14198,14 @@ snapshots:
     transitivePeerDependencies:
       - encoding
 
-  '@fern-fern/generators-sdk@0.107.0-00fe26566':
-    dependencies:
-      form-data: 4.0.0
-      formdata-node: 6.0.3
-      js-base64: 3.7.2
-      node-fetch: 2.7.0
-      qs: 6.11.2
-      url-join: 4.0.1
-    transitivePeerDependencies:
-      - encoding
-
-  '@fern-fern/generators-sdk@0.109.0-21be2e5be':
+  '@fern-fern/generators-sdk@0.114.0-5745f9e74':
     dependencies:
       form-data: 4.0.0
       formdata-node: 6.0.3
       js-base64: 3.7.2
       node-fetch: 2.7.0
       qs: 6.11.2
+      readable-stream: 4.5.2
       url-join: 4.0.1
     transitivePeerDependencies:
       - encoding
diff --git a/seed/fastapi/seed.yml b/seed/fastapi/seed.yml
index fa67bbbf2ac..042ea59904a 100644
--- a/seed/fastapi/seed.yml
+++ b/seed/fastapi/seed.yml
@@ -2,6 +2,17 @@ irVersion: v53
 displayName: FastAPI
 image: fernapi/fern-fastapi-server
 changelogLocation: ../../generators/python/fastapi/versions.yml
+
+artifactMetadata:
+  preInstallScript:
+    - pip install poetry
+    - poetry shell
+    - poetry env use 3.9
+  installScript:
+    - poetry install
+  compileScript:
+    - poetry run mypy .
+
 publish:
   workingDirectory: generators/python
   preBuildCommands:
diff --git a/seed/go-fiber/seed.yml b/seed/go-fiber/seed.yml
index df91eabd1b4..da547785746 100644
--- a/seed/go-fiber/seed.yml
+++ b/seed/go-fiber/seed.yml
@@ -2,6 +2,18 @@ irVersion: v40
 displayName: Fiber
 image: fernapi/fern-go-fiber
 changelogLocation: ../../generators/go/fiber/versions.yml
+
+artifactMetadata:
+  preInstallScript:
+    - sudo yum -y install go
+    - mkdir /tmp/go
+    - echo "export GOPATH=\$HOME/go" >> ~/.bash_profile
+    - source ~/.bash_profile
+  compileScript:
+    - go build -v ./...
+  testScript:
+    - go test -v ./...
+
 publish:
   workingDirectory: generators/go
   preBuildCommands:
@@ -37,7 +49,7 @@ scripts:
   - docker: golang:1.18-alpine
     commands:
       - CGO_ENABLED=0 go test ./...
-allowedFailures: 
+allowedFailures:
   - exhaustive
   - reserved-keywords
   - trace
diff --git a/seed/go-model/seed.yml b/seed/go-model/seed.yml
index 827b98a5b74..ce38c1b3222 100644
--- a/seed/go-model/seed.yml
+++ b/seed/go-model/seed.yml
@@ -2,6 +2,18 @@ irVersion: v40
 displayName: Go Model
 image: fernapi/fern-go-model
 changelogLocation: ../../generators/go/model/versions.yml
+
+artifactMetadata:
+  preInstallScript:
+    - sudo yum -y install go
+    - mkdir /tmp/go
+    - echo "export GOPATH=\$HOME/go" >> ~/.bash_profile
+    - source ~/.bash_profile
+  compileScript:
+    - go build -v ./...
+  testScript:
+    - go test -v ./...
+
 publish:
   workingDirectory: generators/go
   preBuildCommands:
@@ -37,7 +49,7 @@ scripts:
   - docker: golang:1.18-alpine
     commands:
       - CGO_ENABLED=0 go test ./...
-allowedFailures: 
+allowedFailures:
   - exhaustive
   - reserved-keywords
   - trace
diff --git a/seed/go-sdk/seed.yml b/seed/go-sdk/seed.yml
index b33391195ee..3c148582960 100644
--- a/seed/go-sdk/seed.yml
+++ b/seed/go-sdk/seed.yml
@@ -2,6 +2,18 @@ irVersion: v40
 displayName: Go SDK
 image: fernapi/fern-go-sdk
 changelogLocation: ../../generators/go/sdk/versions.yml
+
+artifactMetadata:
+  preInstallScript:
+    - sudo yum -y install go
+    - mkdir /tmp/go
+    - echo "export GOPATH=\$HOME/go" >> ~/.bash_profile
+    - source ~/.bash_profile
+  compileScript:
+    - go build -v ./...
+  testScript:
+    - go test -v ./...
+
 publish:
   workingDirectory: generators/go
   preBuildCommands:
@@ -59,7 +71,7 @@ scripts:
   - docker: golang:1.18-alpine
     commands:
       - CGO_ENABLED=0 go test ./...
-allowedFailures: 
+allowedFailures:
   - exhaustive
   - reserved-keywords
   - server-sent-events
diff --git a/seed/java-model/seed.yml b/seed/java-model/seed.yml
index 51e1e11f7ac..6b96b41634d 100644
--- a/seed/java-model/seed.yml
+++ b/seed/java-model/seed.yml
@@ -2,18 +2,23 @@ irVersion: v46
 displayName: Java Model
 changelogLocation: ../../generators/java/model/versions.yml
 image: fernapi/fern-java-model
+
+artifactMetadata:
+  compileScript:
+    - ./gradlew compileJava
+
 publish:
   workingDirectory: generators/java
   preBuildCommands:
     - ./gradlew :model:distTar
-  docker: 
+  docker:
     file: ./generators/java/model/Dockerfile
     image: fernapi/fern-java-model
     context: ./generators/java/model
 test:
   docker:
     image: fernapi/fern-java-model:latest
-    command: 
+    command:
       - cd generators/java
       - ./gradlew :model:distTar
       - docker build -f model/Dockerfile -t fernapi/fern-java-model:latest model/
diff --git a/seed/java-sdk/seed.yml b/seed/java-sdk/seed.yml
index 4eed30fd713..0bcfbd3dda6 100644
--- a/seed/java-sdk/seed.yml
+++ b/seed/java-sdk/seed.yml
@@ -2,18 +2,23 @@ irVersion: v46
 displayName: Java SDK
 changelogLocation: ../../generators/java/sdk/versions.yml
 image: fernapi/fern-java-sdk
+
+artifactMetadata:
+  compileScript:
+    - ./gradlew compileJava
+
 publish:
   workingDirectory: generators/java
   preBuildCommands:
     - ./gradlew :sdk:distTar
-  docker: 
+  docker:
     file: ./generators/java/sdk/Dockerfile
     image: fernapi/fern-java-sdk
     context: ./generators/java/sdk
 test:
   docker:
     image: fernapi/fern-java-sdk:latest
-    command: 
+    command:
       - cd generators/java
       - ./gradlew :sdk:distTar
       - docker build -f sdk/Dockerfile -t fernapi/fern-java-sdk:latest sdk/
@@ -63,9 +68,9 @@ fixtures:
         coordinate: com.fern:exhaustive
         registryUrl: "definitelyMavenCentral"
         signature:
-            keyId: "test_kid"
-            password: "test_password"
-            secretKey: "test_secretkey"
+          keyId: "test_kid"
+          password: "test_password"
+          secretKey: "test_secretkey"
       publishMetadata:
         packageDescription: My very good and lengthy description
         publisherEmail: "me@gmail.com"
diff --git a/seed/pydantic/seed.yml b/seed/pydantic/seed.yml
index e6583f8246d..c98659602ec 100644
--- a/seed/pydantic/seed.yml
+++ b/seed/pydantic/seed.yml
@@ -2,6 +2,17 @@ irVersion: v53
 displayName: Pydantic Model
 image: fernapi/fern-pydantic-model
 changelogLocation: ../../generators/python/pydantic/versions.yml
+
+artifactMetadata:
+  preInstallScript:
+    - pip install poetry
+    - poetry shell
+    - poetry env use 3.9
+  installScript:
+    - poetry install
+  compileScript:
+    - poetry run mypy .
+
 publish:
   workingDirectory: generators/python
   preBuildCommands:
diff --git a/seed/python-sdk/seed.yml b/seed/python-sdk/seed.yml
index 3af5bde662b..e68d6527c3e 100644
--- a/seed/python-sdk/seed.yml
+++ b/seed/python-sdk/seed.yml
@@ -2,6 +2,20 @@ irVersion: v53
 displayName: Python SDK
 image: fernapi/fern-python-sdk
 changelogLocation: ../../generators/python/sdk/versions.yml
+
+artifactMetadata:
+  preInstallScript:
+    - pip install poetry
+    - poetry shell
+    - poetry env use 3.9
+  installScript:
+    - poetry install
+  compileScript:
+    - poetry run mypy .
+  testScript:
+    # TODO: we need to delineate between snippet testing and regular testing, e.g. just poetry run pytest -rP .
+    - fern test "poetry run pytest -rP ."
+
 publish:
   workingDirectory: generators/python
   preBuildCommands:
@@ -9,7 +23,7 @@ publish:
     - poetry shell
     - poetry config virtualenvs.in-project true
     - poetry install
-  docker: 
+  docker:
     file: ./generators/python/sdk/Dockerfile
     image: fernapi/fern-python-sdk
     context: ./generators/python
@@ -25,22 +39,22 @@ test:
       - poetry install
     # The envvar is needed to trick the generator to look in the right place for the core_utils files
     runCommand: poetry run python -m src.fern_python.generators.sdk.cli
-    env: 
+    env:
       PYTEST_CURRENT_TEST: "some value"
 
 language: python
 generatorType: sdk
 defaultOutputMode: github
 customFixtureConfig:
-  customConfig: 
+  customConfig:
     use_typeddict_requests: true
   outputFolder: client-filename
 fixtures:
-  examples: 
+  examples:
     - customConfig: null
       outputFolder: no-custom-config
-    - customConfig: 
-        client: 
+    - customConfig:
+        client:
           filename: base_client.py
           class_name: BaseSeedExhaustive
           exported_filename: client.py
@@ -102,10 +116,10 @@ fixtures:
         pyproject_python_version: "^3.8.1"
         extra_dependencies:
           boto3: 1.28.57
-          langchain: 
+          langchain:
             version: "^0.1.20"
             optional: true
-        extras: 
+        extras:
           telemetry: ["langchain", "boto3"]
       outputFolder: extra_dependencies
     - customConfig:
@@ -114,7 +128,7 @@ fixtures:
           langchain: "^0.1.3"
           openai: "^1.9.0"
           langchain-openai: "^0.0.3"
-          covcheck: 
+          covcheck:
             version: "^0.4.3"
             extras: ["toml"]
         extra_dependencies:
@@ -129,7 +143,7 @@ fixtures:
     - customConfig:
         pyproject_python_version: "^3.8.1"
         extra_dev_dependencies:
-          covcheck: 
+          covcheck:
             version: "^0.4.3"
             extras: ["toml"]
         pyproject_toml: |
@@ -236,7 +250,7 @@ scripts:
       - poetry install
       - poetry run mypy ./src ./tests
       - fern test --command "poetry run pytest -rP ."
-allowedFailures: 
+allowedFailures:
   # This is the only one that should always fail
   - exhaustive:additional_init_exports
   # This should only succeed in Pydantic V1 tests
@@ -273,7 +287,7 @@ allowedFailures:
 
   # TODO(FER-2946): Support deep object query parameter arrays in the mock
   # server the mock server today doesn't take into account the shape of the
-  # request from the IR and so doesn't know the shape to explicitly coerce 
+  # request from the IR and so doesn't know the shape to explicitly coerce
   # the query string into
   - query-parameters
 
diff --git a/seed/ruby-model/seed.yml b/seed/ruby-model/seed.yml
index 3ab4d5cff0a..f92b43a5680 100644
--- a/seed/ruby-model/seed.yml
+++ b/seed/ruby-model/seed.yml
@@ -2,10 +2,11 @@ irVersion: v39
 displayName: Ruby Model
 image: fernapi/fern-ruby-model
 changelogLocation: ../../generators/ruby/model/versions.yml
+
 publish:
   preBuildCommands:
     - pnpm --filter @fern-api/fern-ruby-model dist:cli
-  docker: 
+  docker:
     file: ./generators/ruby/model/Dockerfile
     image: fernapi/fern-ruby-model
     context: .
@@ -19,6 +20,6 @@ defaultOutputMode: local_files
 fixtures: []
 scripts: []
 allowedFailures:
-    # TODO: Add support for recursive undiscriminated unions.
+  # TODO: Add support for recursive undiscriminated unions.
   - grpc
-  - circular-references
\ No newline at end of file
+  - circular-references
diff --git a/seed/ruby-sdk/seed.yml b/seed/ruby-sdk/seed.yml
index 02082c59707..bd27b905a02 100644
--- a/seed/ruby-sdk/seed.yml
+++ b/seed/ruby-sdk/seed.yml
@@ -2,11 +2,18 @@ irVersion: v39
 displayName: Ruby SDK
 image: fernapi/fern-ruby-sdk
 changelogLocation: ../../generators/ruby/sdk/versions.yml
+
+artifactMetadata:
+  installScript:
+    - bundle install
+  testScript:
+    - bundle exec rake test
+
 publish:
   preBuildCommands:
     - ./.github/actions/install
     - pnpm --filter @fern-api/fern-ruby-sdk dist:cli
-  docker: 
+  docker:
     file: ./generators/ruby/sdk/Dockerfile
     image: fernapi/fern-ruby-sdk
     context: .
@@ -18,7 +25,7 @@ language: ruby
 generatorType: sdk
 defaultOutputMode: github
 fixtures:
-  exhaustive: 
+  exhaustive:
     - customConfig: null
       outputFolder: no-custom-config
     - customConfig:
@@ -69,4 +76,4 @@ features:
 scripts:
   - docker: ruby:2.7
     commands:
-      - bundle install && bundle exec rake test
\ No newline at end of file
+      - bundle install && bundle exec rake test
diff --git a/seed/ts-express/seed.yml b/seed/ts-express/seed.yml
index 66f691f2f30..93a6fac0cee 100644
--- a/seed/ts-express/seed.yml
+++ b/seed/ts-express/seed.yml
@@ -2,28 +2,35 @@ irVersion: v53
 displayName: TypeScript Express
 changelogLocation: ../../generators/typescript/express/versions.yml
 image: fernapi/fern-typescript-express
+
+artifactMetadata:
+  installScript:
+    - yarn install
+  compileScript:
+    - yarn build
+
 publish:
   versionSubstitution: "$VERSION"
-  command: 
+  command:
     - pnpm --filter @fern-typescript/express-generator-cli dockerTagVersion "$VERSION"
     - docker push fernapi/fern-typescript-express:"$VERSION"
 test:
   docker:
     image: fernapi/fern-typescript-express:local
     command: pnpm --filter @fern-typescript/express-generator-cli dockerTagLocal
-  local: 
+  local:
     workingDirectory: generators/typescript
-    buildCommand: 
-      - pnpm --filter @fern-typescript/express-generator-cli compile 
+    buildCommand:
+      - pnpm --filter @fern-typescript/express-generator-cli compile
       - pnpm --filter @fern-typescript/express-generator-cli build
     runCommand: node express/cli/dist/cli.cjs
-    env: 
+    env:
       NODE_ENV: test
 
 language: typescript
 generatorType: Server
 defaultOutputMode: local_files
-defaultCustomConfig: 
+defaultCustomConfig:
   outputSourceFiles: true
 fixtures:
   ts-express-casing:
@@ -44,13 +51,13 @@ fixtures:
     - customConfig:
         outputSourceFiles: false
       outputFolder: output-compiled
-    - customConfig: 
+    - customConfig:
         skipRequestValidation: true
       outputFolder: skip-request-validation
-    - customConfig: 
+    - customConfig:
         skipResponseValidation: true
       outputFolder: skip-response-validation
-    - customConfig: 
+    - customConfig:
         requestValidationStatusCode: 400
       outputFolder: validation-status-code
   exhaustive:
@@ -85,5 +92,3 @@ allowedFailures:
   - streaming
   - streaming-parameter
   - server-sent-events
-
-

From 7d15c3be110b7ff3fe06926c34788f9db0ffc0f1 Mon Sep 17 00:00:00 2001
From: armandobelardo <armandoubelardo@gmail.com>
Date: Tue, 1 Oct 2024 19:13:54 -0400
Subject: [PATCH 2/9] add c# too

---
 seed/csharp-model/seed.yml |  7 ++++++-
 seed/csharp-sdk/seed.yml   | 15 +++++++++++----
 seed/fastapi/seed.yml      |  5 +----
 seed/go-fiber/seed.yml     |  5 -----
 seed/go-model/seed.yml     |  5 -----
 seed/go-sdk/seed.yml       |  5 -----
 seed/pydantic/seed.yml     |  5 +----
 seed/python-sdk/seed.yml   |  5 +----
 8 files changed, 20 insertions(+), 32 deletions(-)

diff --git a/seed/csharp-model/seed.yml b/seed/csharp-model/seed.yml
index e4c45ac24b8..76844bbf696 100644
--- a/seed/csharp-model/seed.yml
+++ b/seed/csharp-model/seed.yml
@@ -2,11 +2,16 @@ irVersion: v53
 displayName: C# Model
 image: fernapi/fern-csharp-model
 changelogLocation: ../../generators/csharp/model/versions.yml
+
+artifactMetadata:
+  compileScript:
+    - dotnet build src -c Release /p:ContinuousIntegrationBuild=true .
+
 publish:
   preBuildCommands:
     - ./.github/actions/install
     - pnpm --filter @fern-api/fern-csharp-model dist:cli
-  docker: 
+  docker:
     file: ./generators/csharp/model/Dockerfile
     image: fernapi/fern-csharp-model
     context: .
diff --git a/seed/csharp-sdk/seed.yml b/seed/csharp-sdk/seed.yml
index 913ad850fcc..4c824ea3d09 100644
--- a/seed/csharp-sdk/seed.yml
+++ b/seed/csharp-sdk/seed.yml
@@ -2,10 +2,17 @@ displayName: C# SDK
 irVersion: v53
 image: fernapi/fern-csharp-sdk
 changelogLocation: ../../generators/csharp/sdk/versions.yml
+
+artifactMetadata:
+  compileScript:
+    - dotnet build src -c Release /p:ContinuousIntegrationBuild=true .
+  testScript:
+    - dotnet test src
+
 publish:
   preBuildCommands:
     - pnpm --filter @fern-api/fern-csharp-sdk dist:cli
-  docker: 
+  docker:
     file: ./generators/csharp/sdk/Dockerfile
     image: fernapi/fern-csharp-sdk
     context: .
@@ -13,9 +20,9 @@ test:
   docker:
     image: fernapi/fern-csharp-sdk:latest
     command: pnpm --filter @fern-api/fern-csharp-sdk dockerTagLatest
-  local: 
+  local:
     workingDirectory: generators/csharp
-    buildCommand: 
+    buildCommand:
       - pnpm --filter @fern-api/fern-csharp-sdk dist:cli
     runCommand: node sdk/dist/bundle.cjs
 
@@ -31,7 +38,7 @@ scripts:
       - dotnet test src --filter "FullyQualifiedName~SeedApi.Test.Core"
       # - dotnet test src
 
-fixtures: 
+fixtures:
   examples:
     - customConfig: null
       outputFolder: no-custom-config
diff --git a/seed/fastapi/seed.yml b/seed/fastapi/seed.yml
index 042ea59904a..188d2af67a5 100644
--- a/seed/fastapi/seed.yml
+++ b/seed/fastapi/seed.yml
@@ -4,11 +4,8 @@ image: fernapi/fern-fastapi-server
 changelogLocation: ../../generators/python/fastapi/versions.yml
 
 artifactMetadata:
-  preInstallScript:
-    - pip install poetry
-    - poetry shell
-    - poetry env use 3.9
   installScript:
+    - poetry shell
     - poetry install
   compileScript:
     - poetry run mypy .
diff --git a/seed/go-fiber/seed.yml b/seed/go-fiber/seed.yml
index da547785746..809863c2e4e 100644
--- a/seed/go-fiber/seed.yml
+++ b/seed/go-fiber/seed.yml
@@ -4,11 +4,6 @@ image: fernapi/fern-go-fiber
 changelogLocation: ../../generators/go/fiber/versions.yml
 
 artifactMetadata:
-  preInstallScript:
-    - sudo yum -y install go
-    - mkdir /tmp/go
-    - echo "export GOPATH=\$HOME/go" >> ~/.bash_profile
-    - source ~/.bash_profile
   compileScript:
     - go build -v ./...
   testScript:
diff --git a/seed/go-model/seed.yml b/seed/go-model/seed.yml
index ce38c1b3222..57ece17dbed 100644
--- a/seed/go-model/seed.yml
+++ b/seed/go-model/seed.yml
@@ -4,11 +4,6 @@ image: fernapi/fern-go-model
 changelogLocation: ../../generators/go/model/versions.yml
 
 artifactMetadata:
-  preInstallScript:
-    - sudo yum -y install go
-    - mkdir /tmp/go
-    - echo "export GOPATH=\$HOME/go" >> ~/.bash_profile
-    - source ~/.bash_profile
   compileScript:
     - go build -v ./...
   testScript:
diff --git a/seed/go-sdk/seed.yml b/seed/go-sdk/seed.yml
index 3c148582960..dc371fd7eeb 100644
--- a/seed/go-sdk/seed.yml
+++ b/seed/go-sdk/seed.yml
@@ -4,11 +4,6 @@ image: fernapi/fern-go-sdk
 changelogLocation: ../../generators/go/sdk/versions.yml
 
 artifactMetadata:
-  preInstallScript:
-    - sudo yum -y install go
-    - mkdir /tmp/go
-    - echo "export GOPATH=\$HOME/go" >> ~/.bash_profile
-    - source ~/.bash_profile
   compileScript:
     - go build -v ./...
   testScript:
diff --git a/seed/pydantic/seed.yml b/seed/pydantic/seed.yml
index c98659602ec..b9f7f0bcab9 100644
--- a/seed/pydantic/seed.yml
+++ b/seed/pydantic/seed.yml
@@ -4,11 +4,8 @@ image: fernapi/fern-pydantic-model
 changelogLocation: ../../generators/python/pydantic/versions.yml
 
 artifactMetadata:
-  preInstallScript:
-    - pip install poetry
-    - poetry shell
-    - poetry env use 3.9
   installScript:
+    - poetry shell
     - poetry install
   compileScript:
     - poetry run mypy .
diff --git a/seed/python-sdk/seed.yml b/seed/python-sdk/seed.yml
index e68d6527c3e..3e100211ed0 100644
--- a/seed/python-sdk/seed.yml
+++ b/seed/python-sdk/seed.yml
@@ -4,11 +4,8 @@ image: fernapi/fern-python-sdk
 changelogLocation: ../../generators/python/sdk/versions.yml
 
 artifactMetadata:
-  preInstallScript:
-    - pip install poetry
-    - poetry shell
-    - poetry env use 3.9
   installScript:
+    - poetry shell
     - poetry install
   compileScript:
     - poetry run mypy .

From bc1c0ff6f3533c969f07d3970e8be89d7b2f4760 Mon Sep 17 00:00:00 2001
From: armandobelardo <armandoubelardo@gmail.com>
Date: Tue, 1 Oct 2024 19:16:00 -0400
Subject: [PATCH 3/9] saw this somewhere

---
 seed/csharp-sdk/seed.yml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/seed/csharp-sdk/seed.yml b/seed/csharp-sdk/seed.yml
index 4c824ea3d09..77b09712a5a 100644
--- a/seed/csharp-sdk/seed.yml
+++ b/seed/csharp-sdk/seed.yml
@@ -4,6 +4,8 @@ image: fernapi/fern-csharp-sdk
 changelogLocation: ../../generators/csharp/sdk/versions.yml
 
 artifactMetadata:
+  preInstallScript:
+    - dotnet tool restore
   compileScript:
     - dotnet build src -c Release /p:ContinuousIntegrationBuild=true .
   testScript:

From d84b634ea00959ecc98ac6b9819c3a43589a0bca Mon Sep 17 00:00:00 2001
From: armandobelardo <armandoubelardo@gmail.com>
Date: Tue, 1 Oct 2024 19:16:58 -0400
Subject: [PATCH 4/9] also update this action

---
 .github/workflows/validate-changelog.yml | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/validate-changelog.yml b/.github/workflows/validate-changelog.yml
index 6fd69dd84b3..0cdac9c55b5 100644
--- a/.github/workflows/validate-changelog.yml
+++ b/.github/workflows/validate-changelog.yml
@@ -31,7 +31,22 @@ jobs:
   generator-validate:
     strategy:
       matrix:
-        generator: [fastapi, pydantic, python-sdk, go-sdk, ruby-sdk, postman, openapi, java-sdk, java-model, java-spring, ts-express]
+        generator:
+          [
+            fastapi,
+            pydantic,
+            python-sdk,
+            go-sdk,
+            ruby-sdk,
+            postman,
+            openapi,
+            java-sdk,
+            java-model,
+            java-spring,
+            ts-express,
+            csharp-sdk,
+            csharp-model
+          ]
 
     runs-on: ubuntu-latest
     steps:

From 6e1983c19577379e55b067cee2e823d69a7ea9cd Mon Sep 17 00:00:00 2001
From: armandobelardo <armandoubelardo@gmail.com>
Date: Wed, 2 Oct 2024 19:55:26 -0400
Subject: [PATCH 5/9] cr

---
 packages/seed/fern/definition/config.yml                    | 6 +++---
 packages/seed/src/commands/register/registerGenerator.ts    | 2 +-
 .../config/types/{ArtifactMetadata.ts => BuildScripts.ts}   | 4 ++--
 .../resources/config/types/SeedWorkspaceConfiguration.ts    | 2 +-
 .../seed/src/config/api/resources/config/types/index.ts     | 2 +-
 seed/csharp-model/seed.yml                                  | 2 +-
 seed/csharp-sdk/seed.yml                                    | 2 +-
 seed/fastapi/seed.yml                                       | 2 +-
 seed/go-fiber/seed.yml                                      | 2 +-
 seed/go-model/seed.yml                                      | 2 +-
 seed/go-sdk/seed.yml                                        | 2 +-
 seed/java-model/seed.yml                                    | 2 +-
 seed/java-sdk/seed.yml                                      | 2 +-
 seed/pydantic/seed.yml                                      | 2 +-
 seed/python-sdk/seed.yml                                    | 2 +-
 seed/ruby-sdk/seed.yml                                      | 2 +-
 seed/ts-express/seed.yml                                    | 2 +-
 17 files changed, 20 insertions(+), 20 deletions(-)
 rename packages/seed/src/config/api/resources/config/types/{ArtifactMetadata.ts => BuildScripts.ts} (64%)

diff --git a/packages/seed/fern/definition/config.yml b/packages/seed/fern/definition/config.yml
index 0a9fbbd6a04..83e76670603 100644
--- a/packages/seed/fern/definition/config.yml
+++ b/packages/seed/fern/definition/config.yml
@@ -28,7 +28,7 @@ types:
       defaultOutputMode: OutputMode
       generatorType: GeneratorType
 
-      artifactMetadata: optional<ArtifactMetadata>
+      buildScripts: optional<BuildScripts>
 
       customFixtureConfig:
         type: optional<FixtureConfigurations>
@@ -108,8 +108,8 @@ types:
         docs: |
           Environment variables to set when running the generator locally.
 
-  ArtifactMetadata:
-    docs: Metadata relating to the artifact produced by this generator
+  BuildScripts:
+    docs: Scripts pertaining to the artifact produced by this generator and how to build them (e.g. yarn install && yarn build for the TS SDK)
     properties:
       preInstallScript: optional<Script>
       installScript: optional<Script>
diff --git a/packages/seed/src/commands/register/registerGenerator.ts b/packages/seed/src/commands/register/registerGenerator.ts
index 34c2a6f27ed..d04fae370c6 100644
--- a/packages/seed/src/commands/register/registerGenerator.ts
+++ b/packages/seed/src/commands/register/registerGenerator.ts
@@ -26,7 +26,7 @@ export async function registerGenerator({
         generatorType: convertGeneratorType(generatorConfig.generatorType),
         generatorLanguage: generatorConfig.language,
         dockerImage: generatorConfig.image,
-        scripts: generatorConfig.artifactMetadata
+        scripts: generatorConfig.buildScripts
     });
 
     // Register generator versions
diff --git a/packages/seed/src/config/api/resources/config/types/ArtifactMetadata.ts b/packages/seed/src/config/api/resources/config/types/BuildScripts.ts
similarity index 64%
rename from packages/seed/src/config/api/resources/config/types/ArtifactMetadata.ts
rename to packages/seed/src/config/api/resources/config/types/BuildScripts.ts
index 6ab8b456375..76bd9d80867 100644
--- a/packages/seed/src/config/api/resources/config/types/ArtifactMetadata.ts
+++ b/packages/seed/src/config/api/resources/config/types/BuildScripts.ts
@@ -5,9 +5,9 @@
 import * as FernSeedConfig from "../../..";
 
 /**
- * Metadata relating to the artifact produced by this generator
+ * Scripts pertaining to the artifact produced by this generator and how to build them (e.g. yarn install && yarn build for the TS SDK)
  */
-export interface ArtifactMetadata {
+export interface BuildScripts {
     preInstallScript?: FernSeedConfig.Script;
     installScript?: FernSeedConfig.Script;
     compileScript?: FernSeedConfig.Script;
diff --git a/packages/seed/src/config/api/resources/config/types/SeedWorkspaceConfiguration.ts b/packages/seed/src/config/api/resources/config/types/SeedWorkspaceConfiguration.ts
index c0d5603c50d..7f0be061127 100644
--- a/packages/seed/src/config/api/resources/config/types/SeedWorkspaceConfiguration.ts
+++ b/packages/seed/src/config/api/resources/config/types/SeedWorkspaceConfiguration.ts
@@ -16,7 +16,7 @@ export interface SeedWorkspaceConfiguration {
     defaultCustomConfig?: Record<string, unknown>;
     defaultOutputMode: FernSeedConfig.OutputMode;
     generatorType: FernSeedConfig.GeneratorType;
-    artifactMetadata?: FernSeedConfig.ArtifactMetadata;
+    buildScripts?: FernSeedConfig.BuildScripts;
     /** Configuration that will be used for any custom fixture specified by --custom-fixture */
     customFixtureConfig?: FernSeedConfig.FixtureConfigurations;
     fixtures?: Record<string, FernSeedConfig.FixtureConfigurations[]>;
diff --git a/packages/seed/src/config/api/resources/config/types/index.ts b/packages/seed/src/config/api/resources/config/types/index.ts
index d60301c91fe..45a50828934 100644
--- a/packages/seed/src/config/api/resources/config/types/index.ts
+++ b/packages/seed/src/config/api/resources/config/types/index.ts
@@ -7,7 +7,7 @@ export * from "./PublishConfiguration";
 export * from "./TestDockerConfiguration";
 export * from "./TestConfiguration";
 export * from "./LocalBuildInfo";
-export * from "./ArtifactMetadata";
+export * from "./BuildScripts";
 export * from "./DockerCommand";
 export * from "./Script";
 export * from "./DockerScriptConfig";
diff --git a/seed/csharp-model/seed.yml b/seed/csharp-model/seed.yml
index 76844bbf696..0fb7902b7c4 100644
--- a/seed/csharp-model/seed.yml
+++ b/seed/csharp-model/seed.yml
@@ -3,7 +3,7 @@ displayName: C# Model
 image: fernapi/fern-csharp-model
 changelogLocation: ../../generators/csharp/model/versions.yml
 
-artifactMetadata:
+buildScripts:
   compileScript:
     - dotnet build src -c Release /p:ContinuousIntegrationBuild=true .
 
diff --git a/seed/csharp-sdk/seed.yml b/seed/csharp-sdk/seed.yml
index 77b09712a5a..bc84fdc7b14 100644
--- a/seed/csharp-sdk/seed.yml
+++ b/seed/csharp-sdk/seed.yml
@@ -3,7 +3,7 @@ irVersion: v53
 image: fernapi/fern-csharp-sdk
 changelogLocation: ../../generators/csharp/sdk/versions.yml
 
-artifactMetadata:
+buildScripts:
   preInstallScript:
     - dotnet tool restore
   compileScript:
diff --git a/seed/fastapi/seed.yml b/seed/fastapi/seed.yml
index 188d2af67a5..0695c5764da 100644
--- a/seed/fastapi/seed.yml
+++ b/seed/fastapi/seed.yml
@@ -3,7 +3,7 @@ displayName: FastAPI
 image: fernapi/fern-fastapi-server
 changelogLocation: ../../generators/python/fastapi/versions.yml
 
-artifactMetadata:
+buildScripts:
   installScript:
     - poetry shell
     - poetry install
diff --git a/seed/go-fiber/seed.yml b/seed/go-fiber/seed.yml
index 809863c2e4e..f72a1588392 100644
--- a/seed/go-fiber/seed.yml
+++ b/seed/go-fiber/seed.yml
@@ -3,7 +3,7 @@ displayName: Fiber
 image: fernapi/fern-go-fiber
 changelogLocation: ../../generators/go/fiber/versions.yml
 
-artifactMetadata:
+buildScripts:
   compileScript:
     - go build -v ./...
   testScript:
diff --git a/seed/go-model/seed.yml b/seed/go-model/seed.yml
index 57ece17dbed..1b7bd73230e 100644
--- a/seed/go-model/seed.yml
+++ b/seed/go-model/seed.yml
@@ -3,7 +3,7 @@ displayName: Go Model
 image: fernapi/fern-go-model
 changelogLocation: ../../generators/go/model/versions.yml
 
-artifactMetadata:
+buildScripts:
   compileScript:
     - go build -v ./...
   testScript:
diff --git a/seed/go-sdk/seed.yml b/seed/go-sdk/seed.yml
index dc371fd7eeb..2ca4a645529 100644
--- a/seed/go-sdk/seed.yml
+++ b/seed/go-sdk/seed.yml
@@ -3,7 +3,7 @@ displayName: Go SDK
 image: fernapi/fern-go-sdk
 changelogLocation: ../../generators/go/sdk/versions.yml
 
-artifactMetadata:
+buildScripts:
   compileScript:
     - go build -v ./...
   testScript:
diff --git a/seed/java-model/seed.yml b/seed/java-model/seed.yml
index 6b96b41634d..adc6e588be0 100644
--- a/seed/java-model/seed.yml
+++ b/seed/java-model/seed.yml
@@ -3,7 +3,7 @@ displayName: Java Model
 changelogLocation: ../../generators/java/model/versions.yml
 image: fernapi/fern-java-model
 
-artifactMetadata:
+buildScripts:
   compileScript:
     - ./gradlew compileJava
 
diff --git a/seed/java-sdk/seed.yml b/seed/java-sdk/seed.yml
index 0bcfbd3dda6..732f288d55d 100644
--- a/seed/java-sdk/seed.yml
+++ b/seed/java-sdk/seed.yml
@@ -3,7 +3,7 @@ displayName: Java SDK
 changelogLocation: ../../generators/java/sdk/versions.yml
 image: fernapi/fern-java-sdk
 
-artifactMetadata:
+buildScripts:
   compileScript:
     - ./gradlew compileJava
 
diff --git a/seed/pydantic/seed.yml b/seed/pydantic/seed.yml
index b9f7f0bcab9..cfe35798280 100644
--- a/seed/pydantic/seed.yml
+++ b/seed/pydantic/seed.yml
@@ -3,7 +3,7 @@ displayName: Pydantic Model
 image: fernapi/fern-pydantic-model
 changelogLocation: ../../generators/python/pydantic/versions.yml
 
-artifactMetadata:
+buildScripts:
   installScript:
     - poetry shell
     - poetry install
diff --git a/seed/python-sdk/seed.yml b/seed/python-sdk/seed.yml
index 3e100211ed0..9348712c89f 100644
--- a/seed/python-sdk/seed.yml
+++ b/seed/python-sdk/seed.yml
@@ -3,7 +3,7 @@ displayName: Python SDK
 image: fernapi/fern-python-sdk
 changelogLocation: ../../generators/python/sdk/versions.yml
 
-artifactMetadata:
+buildScripts:
   installScript:
     - poetry shell
     - poetry install
diff --git a/seed/ruby-sdk/seed.yml b/seed/ruby-sdk/seed.yml
index bd27b905a02..eb090e4b117 100644
--- a/seed/ruby-sdk/seed.yml
+++ b/seed/ruby-sdk/seed.yml
@@ -3,7 +3,7 @@ displayName: Ruby SDK
 image: fernapi/fern-ruby-sdk
 changelogLocation: ../../generators/ruby/sdk/versions.yml
 
-artifactMetadata:
+buildScripts:
   installScript:
     - bundle install
   testScript:
diff --git a/seed/ts-express/seed.yml b/seed/ts-express/seed.yml
index 93a6fac0cee..85b41a19a0e 100644
--- a/seed/ts-express/seed.yml
+++ b/seed/ts-express/seed.yml
@@ -3,7 +3,7 @@ displayName: TypeScript Express
 changelogLocation: ../../generators/typescript/express/versions.yml
 image: fernapi/fern-typescript-express
 
-artifactMetadata:
+buildScripts:
   installScript:
     - yarn install
   compileScript:

From c8ef807e4d76ea2b56e2760f5bebd97a4a1e158e Mon Sep 17 00:00:00 2001
From: armandobelardo <armandoubelardo@gmail.com>
Date: Wed, 2 Oct 2024 20:16:14 -0400
Subject: [PATCH 6/9] update test command

---
 seed/python-sdk/seed.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/seed/python-sdk/seed.yml b/seed/python-sdk/seed.yml
index 9348712c89f..4e56411a305 100644
--- a/seed/python-sdk/seed.yml
+++ b/seed/python-sdk/seed.yml
@@ -10,8 +10,8 @@ buildScripts:
   compileScript:
     - poetry run mypy .
   testScript:
-    # TODO: we need to delineate between snippet testing and regular testing, e.g. just poetry run pytest -rP .
-    - fern test "poetry run pytest -rP ."
+    # TODO: we need to acttually run the mock server tests as well
+    - poetry run pytest -rP ./tests/utils
 
 publish:
   workingDirectory: generators/python

From e5af81756118152159169f1278e22770315f3e07 Mon Sep 17 00:00:00 2001
From: armandobelardo <armandoubelardo@gmail.com>
Date: Thu, 3 Oct 2024 08:20:26 -0400
Subject: [PATCH 7/9] update test command to be flexible if path doesn't exist

---
 seed/python-sdk/seed.yml | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/seed/python-sdk/seed.yml b/seed/python-sdk/seed.yml
index 4e56411a305..78878e6106d 100644
--- a/seed/python-sdk/seed.yml
+++ b/seed/python-sdk/seed.yml
@@ -11,7 +11,10 @@ buildScripts:
     - poetry run mypy .
   testScript:
     # TODO: we need to acttually run the mock server tests as well
-    - poetry run pytest -rP ./tests/utils
+    # Note: not all versions of the generator have this test directory which brings in the unit tests we write
+    # as a result, the script here only runs pytest if the directory exists, and exits 0 if it does not (e.g. just passes)
+    - export PYTHON_TEST_DIR="./tests/utils"
+    - if [ -d "$PYTHON_TEST_DIR" ]; then poetry run pytest -rP "$PYTHON_TEST_DIR"; else echo "Test directory not found. Skipping tests."; fi
 
 publish:
   workingDirectory: generators/python

From 2da35dc60b367cdc14c58b5884b0d54057b7b8de Mon Sep 17 00:00:00 2001
From: armandobelardo <armandoubelardo@gmail.com>
Date: Thu, 3 Oct 2024 08:42:55 -0400
Subject: [PATCH 8/9] updates

---
 .../commands/register/registerGenerator.ts    | 23 ++++++++++++++++++-
 .../seed/src/commands/test/ScriptRunner.ts    |  6 ++---
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/packages/seed/src/commands/register/registerGenerator.ts b/packages/seed/src/commands/register/registerGenerator.ts
index d04fae370c6..2b72c9a32ac 100644
--- a/packages/seed/src/commands/register/registerGenerator.ts
+++ b/packages/seed/src/commands/register/registerGenerator.ts
@@ -26,7 +26,28 @@ export async function registerGenerator({
         generatorType: convertGeneratorType(generatorConfig.generatorType),
         generatorLanguage: generatorConfig.language,
         dockerImage: generatorConfig.image,
-        scripts: generatorConfig.buildScripts
+        scripts: {
+            preInstallScript: generatorConfig.buildScripts?.preInstallScript
+                ? {
+                      steps: generatorConfig.buildScripts.preInstallScript.commands
+                  }
+                : undefined,
+            installScript: generatorConfig.buildScripts?.installScript
+                ? {
+                      steps: generatorConfig.buildScripts.installScript.commands
+                  }
+                : undefined,
+            compileScript: generatorConfig.buildScripts?.compileScript
+                ? {
+                      steps: generatorConfig.buildScripts.compileScript.commands
+                  }
+                : undefined,
+            testScript: generatorConfig.buildScripts?.testScript
+                ? {
+                      steps: generatorConfig.buildScripts.testScript.commands
+                  }
+                : undefined
+        }
     });
 
     // Register generator versions
diff --git a/packages/seed/src/commands/test/ScriptRunner.ts b/packages/seed/src/commands/test/ScriptRunner.ts
index 7d55f333b38..81caf52f72b 100644
--- a/packages/seed/src/commands/test/ScriptRunner.ts
+++ b/packages/seed/src/commands/test/ScriptRunner.ts
@@ -3,7 +3,7 @@ import { loggingExeca } from "@fern-api/logging-execa";
 import { TaskContext } from "@fern-api/task-context";
 import { writeFile } from "fs/promises";
 import tmp from "tmp-promise";
-import { ScriptConfig } from "../../config/api";
+import { DockerScriptConfig } from "../../config/api";
 import { GeneratorWorkspace } from "../../loadGeneratorWorkspaces";
 import { Semaphore } from "../../Semaphore";
 
@@ -26,7 +26,7 @@ export declare namespace ScriptRunner {
     }
 }
 
-interface RunningScriptConfig extends ScriptConfig {
+interface RunningScriptConfig extends DockerScriptConfig {
     containerId: string;
 }
 
@@ -78,7 +78,7 @@ export class ScriptRunner {
         outputDir: AbsoluteFilePath;
         taskContext: TaskContext;
         containerId: string;
-        script: ScriptConfig;
+        script: DockerScriptConfig;
     }): Promise<ScriptRunner.RunResponse> {
         taskContext.logger.info(`Running script ${script.commands[0] ?? ""} on ${id}`);
 

From c2eaa4a83317cb016bb1a9c734be38f4968162c1 Mon Sep 17 00:00:00 2001
From: armandobelardo <armandoubelardo@gmail.com>
Date: Thu, 3 Oct 2024 12:27:13 -0400
Subject: [PATCH 9/9] seed

---
 .../server-sent-events/.gitignore             |   9 +-
 .../SeedServerSentEvents.Test.csproj          |   2 +
 .../Completions/StreamedCompletion.cs         |   6 +
 .../Core/CollectionItemSerializer.cs          |   2 +-
 .../SeedServerSentEvents/Core/Constants.cs    |   7 +
 .../Core/DateTimeSerializer.cs                |  22 ++
 .../Core/JsonConfiguration.cs                 |  32 +++
 .../Core/OneOfSerializer.cs                   |  26 +-
 .../Core/Public/Version.cs                    |   6 +
 .../Core/StringEnumSerializer.cs              |   2 +-
 .../SeedServerSentEvents.csproj               |   7 +-
 seed/csharp-sdk/server-sent-events/README.md  |  87 +++++++
 .../server-sent-events/reference.md           |  41 ++++
 .../server-sent-events/snippet-templates.json |   0
 .../server-sent-events/snippet.json           |  17 ++
 .../Core/RawClientTests.cs                    | 113 +++++++++
 .../SeedServerSentEvents.Test.csproj          |   1 +
 .../Utils/JsonDiffChecker.cs                  |  85 -------
 .../Wire/BaseWireTest.cs                      |  36 ---
 .../Completions/CompletionsClient.cs          |  25 +-
 .../Requests/StreamCompletionRequest.cs       |   6 +
 .../Completions/Types/StreamedCompletion.cs   |   6 +
 .../Core/CollectionItemSerializer.cs          |   2 +-
 .../SeedServerSentEvents/Core/Constants.cs    |   3 +-
 .../Core/DateTimeSerializer.cs                |   2 +-
 .../SeedServerSentEvents/Core/Extensions.cs   |  14 ++
 .../SeedServerSentEvents/Core/HeaderValue.cs  |  17 ++
 .../src/SeedServerSentEvents/Core/Headers.cs  |  17 ++
 .../Core/HttpMethodExtensions.cs              |   2 +-
 .../Core/JsonConfiguration.cs                 |   8 +-
 .../Core/OneOfSerializer.cs                   |  26 +-
 .../Core/{ => Public}/ClientOptions.cs        |   8 +-
 .../Core/{ => Public}/RequestOptions.cs       |   8 +-
 .../SeedServerSentEventsApiException.cs       |  11 +-
 .../SeedServerSentEventsException.cs          |   2 +-
 .../Core/Public/Version.cs                    |   6 +
 .../SeedServerSentEvents/Core/RawClient.cs    | 148 +++++++-----
 .../Core/StringEnumSerializer.cs              |   2 +-
 .../SeedServerSentEvents.csproj               |   7 +-
 .../SeedServerSentEventsClient.cs             |  23 +-
 .../model/completions/StreamedCompletion.java |   2 +-
 .../server-sent-events/snippet-templates.json |   0
 seed/java-sdk/server-sent-events/snippet.json |   0
 .../serverSentEvents/core/FileStream.java     |  60 +++++
 .../core/InputStreamRequestBody.java          |  79 +++++++
 .../requests/StreamCompletionRequest.java     |   7 +-
 .../completions/types/StreamedCompletion.java |   7 +-
 .../.github/workflows/ci.yml                  |  48 ++++
 seed/php-model/server-sent-events/.gitignore  |   4 +
 .../.mock/definition/api.yml                  |   1 +
 .../.mock/definition/completions.yml          |  22 ++
 .../server-sent-events/.mock/fern.config.json |   1 +
 .../server-sent-events/.mock/generators.yml   |   1 +
 .../server-sent-events/composer.json          |  40 ++++
 .../php-model/server-sent-events/phpstan.neon |   5 +
 seed/php-model/server-sent-events/phpunit.xml |   7 +
 .../server-sent-events/snippet-templates.json |   0
 .../php-model/server-sent-events/snippet.json |   0
 .../src/Completions/StreamedCompletion.php    |  34 +++
 .../server-sent-events/src/Core/ArrayType.php |  16 ++
 .../server-sent-events/src/Core/Constant.php  |  12 +
 .../server-sent-events/src/Core/DateType.php  |  16 ++
 .../src/Core/JsonDecoder.php                  | 147 ++++++++++++
 .../src/Core/JsonDeserializer.php             | 187 +++++++++++++++
 .../src/Core/JsonEncoder.php                  |  20 ++
 .../src/Core/JsonProperty.php                 |  13 +
 .../src/Core/JsonSerializer.php               | 173 ++++++++++++++
 .../src/Core/SerializableType.php             | 165 +++++++++++++
 .../server-sent-events/src/Core/Union.php     |  21 ++
 .../server-sent-events/src/Core/Utils.php     |  61 +++++
 .../tests/Seed/Core/DateArrayTypeTest.php     |  55 +++++
 .../tests/Seed/Core/EmptyArraysTest.php       |  73 ++++++
 .../tests/Seed/Core/EnumTest.php              |  76 ++++++
 .../tests/Seed/Core/InvalidTypesTest.php      |  45 ++++
 .../Seed/Core/MixedDateArrayTypeTest.php      |  60 +++++
 .../Seed/Core/NestedUnionArrayTypeTest.php    |  99 ++++++++
 .../tests/Seed/Core/NullPropertyTypeTest.php  |  50 ++++
 .../tests/Seed/Core/NullableArrayTypeTest.php |  50 ++++
 .../tests/Seed/Core/ScalarTypesTest.php       | 121 ++++++++++
 .../tests/Seed/Core/TestTypeTest.php          | 201 ++++++++++++++++
 .../tests/Seed/Core/UnionArrayTypeTest.php    |  56 +++++
 .../.github/workflows/ci.yml                  |  48 ++++
 seed/php-sdk/server-sent-events/.gitignore    |   4 +
 .../.mock/definition/api.yml                  |   1 +
 .../.mock/definition/completions.yml          |  22 ++
 .../server-sent-events/.mock/fern.config.json |   1 +
 .../server-sent-events/.mock/generators.yml   |   1 +
 seed/php-sdk/server-sent-events/composer.json |  40 ++++
 seed/php-sdk/server-sent-events/phpstan.neon  |   5 +
 seed/php-sdk/server-sent-events/phpunit.xml   |   7 +
 .../server-sent-events/snippet-templates.json |   0
 seed/php-sdk/server-sent-events/snippet.json  |   0
 .../src/Completions/CompletionsClient.php     |  58 +++++
 .../Requests/StreamCompletionRequest.php      |  26 ++
 .../Completions/Types/StreamedCompletion.php  |  34 +++
 .../server-sent-events/src/Core/ArrayType.php |  16 ++
 .../src/Core/BaseApiRequest.php               |  22 ++
 .../server-sent-events/src/Core/Constant.php  |  12 +
 .../server-sent-events/src/Core/DateType.php  |  16 ++
 .../src/Core/HttpMethod.php                   |  12 +
 .../src/Core/JsonApiRequest.php               |  25 ++
 .../src/Core/JsonDecoder.php                  | 147 ++++++++++++
 .../src/Core/JsonDeserializer.php             | 187 +++++++++++++++
 .../src/Core/JsonEncoder.php                  |  20 ++
 .../src/Core/JsonProperty.php                 |  13 +
 .../src/Core/JsonSerializer.php               | 173 ++++++++++++++
 .../server-sent-events/src/Core/RawClient.php | 138 +++++++++++
 .../src/Core/SerializableType.php             | 165 +++++++++++++
 .../server-sent-events/src/Core/Union.php     |  21 ++
 .../server-sent-events/src/Core/Utils.php     |  61 +++++
 .../src/Exceptions/SeedApiException.php       |  53 +++++
 .../src/Exceptions/SeedException.php          |  12 +
 .../server-sent-events/src/SeedClient.php     |  58 +++++
 .../tests/Seed/Core/DateArrayTypeTest.php     |  55 +++++
 .../tests/Seed/Core/EmptyArraysTest.php       |  73 ++++++
 .../tests/Seed/Core/EnumTest.php              |  76 ++++++
 .../tests/Seed/Core/InvalidTypesTest.php      |  45 ++++
 .../Seed/Core/MixedDateArrayTypeTest.php      |  60 +++++
 .../Seed/Core/NestedUnionArrayTypeTest.php    |  99 ++++++++
 .../tests/Seed/Core/NullPropertyTypeTest.php  |  50 ++++
 .../tests/Seed/Core/NullableArrayTypeTest.php |  50 ++++
 .../tests/Seed/Core/RawClientTest.php         | 101 ++++++++
 .../tests/Seed/Core/ScalarTypesTest.php       | 121 ++++++++++
 .../tests/Seed/Core/TestTypeTest.php          | 201 ++++++++++++++++
 .../tests/Seed/Core/UnionArrayTypeTest.php    |  56 +++++
 .../server-sent-events/collection.json        |  53 ++++-
 .../.github/workflows/ci.yml                  |   2 +-
 .../server-sent-events/pyproject.toml         |   3 +
 .../seed/server_sent_events/core/__init__.py  |   2 -
 .../server_sent_events/core/datetime_utils.py |   4 +-
 .../core/pydantic_utilities.py                | 185 ++++++++++-----
 .../server_sent_events/core/serialization.py  | 181 ++++++++++----
 .../completions/streamed_completion.py        |   4 +-
 seed/python-sdk/server-sent-events/README.md  |  10 +-
 .../resolved-snippet-templates.md             |  11 +
 .../src/seed/core/__init__.py                 |   5 +-
 .../src/seed/core/client_wrapper.py           |  12 +-
 .../server-sent-events/src/seed/core/file.py  |  41 +++-
 .../src/seed/core/http_client.py              |  46 ++--
 .../src/seed/core/pydantic_utilities.py       | 222 +++++++++++++-----
 .../src/seed/core/query_encoder.py            |  45 +++-
 .../src/seed/core/serialization.py            | 178 +++++++++++---
 .../tests/utils/assets/models/circle.py       |   2 +-
 .../assets/models/object_with_defaults.py     |   1 +
 .../models/object_with_optional_field.py      |   9 +-
 .../tests/utils/assets/models/shape.py        |   6 +-
 .../tests/utils/assets/models/square.py       |   2 +-
 .../assets/models/undiscriminated_shape.py    |   1 -
 .../tests/utils/test_query_encoding.py        |  34 ++-
 .../tests/utils/test_serialization.py         |  16 +-
 .../fern_server_sent_events.gemspec           |   4 -
 .../lib/fern_server_sent_events.rb            |  42 +---
 .../completions/client.rb                     |  27 ---
 .../server-sent-events/lib/requests.rb        | 140 -----------
 .../server-sent-events/lib/types_export.rb    |   3 -
 seed/ruby-sdk/server-sent-events/snippet.json |   4 -
 seed/ts-sdk/server-sent-events/README.md      |   6 +-
 seed/ts-sdk/server-sent-events/jest.config.js |   5 +
 seed/ts-sdk/server-sent-events/package.json   |   6 +-
 .../resolved-snippet-templates.md             |  11 +
 .../Node18UniversalStreamWrapper.ts           |   2 +-
 .../stream-wrappers/NodePre18StreamWrapper.ts |   2 +-
 .../stream-wrappers/UndiciStreamWrapper.ts    |   2 +-
 .../stream-wrappers/chooseStreamWrapper.ts    |   4 +-
 .../src/core/schemas/Schema.ts                |   1 +
 .../core/schemas/builders/bigint/bigint.ts    |  50 ++++
 .../src/core/schemas/builders/bigint/index.ts |   1 +
 .../src/core/schemas/builders/index.ts        |   1 +
 .../utils/getErrorMessageForIncorrectType.ts  |   4 +
 seed/ts-sdk/server-sent-events/src/version.ts |   1 +
 .../Node18UniversalStreamWrapper.test.ts      |   2 +-
 .../NodePre18StreamWrapper.test.ts            |  26 +-
 .../chooseStreamWrapper.test.ts               |   2 +-
 .../fetcher/stream-wrappers/webpack.test.ts   |  38 +++
 .../tests/unit/zurg/bigint/bigint.test.ts     |  24 ++
 175 files changed, 5963 insertions(+), 784 deletions(-)
 create mode 100644 seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/Constants.cs
 create mode 100644 seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/DateTimeSerializer.cs
 create mode 100644 seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/JsonConfiguration.cs
 create mode 100644 seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/Public/Version.cs
 create mode 100644 seed/csharp-sdk/server-sent-events/README.md
 create mode 100644 seed/csharp-sdk/server-sent-events/reference.md
 create mode 100644 seed/csharp-sdk/server-sent-events/snippet-templates.json
 create mode 100644 seed/csharp-sdk/server-sent-events/snippet.json
 create mode 100644 seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents.Test/Core/RawClientTests.cs
 delete mode 100644 seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents.Test/Utils/JsonDiffChecker.cs
 delete mode 100644 seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents.Test/Wire/BaseWireTest.cs
 create mode 100644 seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Extensions.cs
 create mode 100644 seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/HeaderValue.cs
 create mode 100644 seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Headers.cs
 rename seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/{ => Public}/ClientOptions.cs (75%)
 rename seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/{ => Public}/RequestOptions.cs (74%)
 rename seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/{ => Public}/SeedServerSentEventsApiException.cs (66%)
 rename seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/{ => Public}/SeedServerSentEventsException.cs (87%)
 create mode 100644 seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Public/Version.cs
 create mode 100644 seed/java-sdk/server-sent-events/snippet-templates.json
 create mode 100644 seed/java-sdk/server-sent-events/snippet.json
 create mode 100644 seed/java-sdk/server-sent-events/src/main/java/com/seed/serverSentEvents/core/FileStream.java
 create mode 100644 seed/java-sdk/server-sent-events/src/main/java/com/seed/serverSentEvents/core/InputStreamRequestBody.java
 create mode 100644 seed/php-model/server-sent-events/.github/workflows/ci.yml
 create mode 100644 seed/php-model/server-sent-events/.gitignore
 create mode 100644 seed/php-model/server-sent-events/.mock/definition/api.yml
 create mode 100644 seed/php-model/server-sent-events/.mock/definition/completions.yml
 create mode 100644 seed/php-model/server-sent-events/.mock/fern.config.json
 create mode 100644 seed/php-model/server-sent-events/.mock/generators.yml
 create mode 100644 seed/php-model/server-sent-events/composer.json
 create mode 100644 seed/php-model/server-sent-events/phpstan.neon
 create mode 100644 seed/php-model/server-sent-events/phpunit.xml
 create mode 100644 seed/php-model/server-sent-events/snippet-templates.json
 create mode 100644 seed/php-model/server-sent-events/snippet.json
 create mode 100644 seed/php-model/server-sent-events/src/Completions/StreamedCompletion.php
 create mode 100644 seed/php-model/server-sent-events/src/Core/ArrayType.php
 create mode 100644 seed/php-model/server-sent-events/src/Core/Constant.php
 create mode 100644 seed/php-model/server-sent-events/src/Core/DateType.php
 create mode 100644 seed/php-model/server-sent-events/src/Core/JsonDecoder.php
 create mode 100644 seed/php-model/server-sent-events/src/Core/JsonDeserializer.php
 create mode 100644 seed/php-model/server-sent-events/src/Core/JsonEncoder.php
 create mode 100644 seed/php-model/server-sent-events/src/Core/JsonProperty.php
 create mode 100644 seed/php-model/server-sent-events/src/Core/JsonSerializer.php
 create mode 100644 seed/php-model/server-sent-events/src/Core/SerializableType.php
 create mode 100644 seed/php-model/server-sent-events/src/Core/Union.php
 create mode 100644 seed/php-model/server-sent-events/src/Core/Utils.php
 create mode 100644 seed/php-model/server-sent-events/tests/Seed/Core/DateArrayTypeTest.php
 create mode 100644 seed/php-model/server-sent-events/tests/Seed/Core/EmptyArraysTest.php
 create mode 100644 seed/php-model/server-sent-events/tests/Seed/Core/EnumTest.php
 create mode 100644 seed/php-model/server-sent-events/tests/Seed/Core/InvalidTypesTest.php
 create mode 100644 seed/php-model/server-sent-events/tests/Seed/Core/MixedDateArrayTypeTest.php
 create mode 100644 seed/php-model/server-sent-events/tests/Seed/Core/NestedUnionArrayTypeTest.php
 create mode 100644 seed/php-model/server-sent-events/tests/Seed/Core/NullPropertyTypeTest.php
 create mode 100644 seed/php-model/server-sent-events/tests/Seed/Core/NullableArrayTypeTest.php
 create mode 100644 seed/php-model/server-sent-events/tests/Seed/Core/ScalarTypesTest.php
 create mode 100644 seed/php-model/server-sent-events/tests/Seed/Core/TestTypeTest.php
 create mode 100644 seed/php-model/server-sent-events/tests/Seed/Core/UnionArrayTypeTest.php
 create mode 100644 seed/php-sdk/server-sent-events/.github/workflows/ci.yml
 create mode 100644 seed/php-sdk/server-sent-events/.gitignore
 create mode 100644 seed/php-sdk/server-sent-events/.mock/definition/api.yml
 create mode 100644 seed/php-sdk/server-sent-events/.mock/definition/completions.yml
 create mode 100644 seed/php-sdk/server-sent-events/.mock/fern.config.json
 create mode 100644 seed/php-sdk/server-sent-events/.mock/generators.yml
 create mode 100644 seed/php-sdk/server-sent-events/composer.json
 create mode 100644 seed/php-sdk/server-sent-events/phpstan.neon
 create mode 100644 seed/php-sdk/server-sent-events/phpunit.xml
 create mode 100644 seed/php-sdk/server-sent-events/snippet-templates.json
 create mode 100644 seed/php-sdk/server-sent-events/snippet.json
 create mode 100644 seed/php-sdk/server-sent-events/src/Completions/CompletionsClient.php
 create mode 100644 seed/php-sdk/server-sent-events/src/Completions/Requests/StreamCompletionRequest.php
 create mode 100644 seed/php-sdk/server-sent-events/src/Completions/Types/StreamedCompletion.php
 create mode 100644 seed/php-sdk/server-sent-events/src/Core/ArrayType.php
 create mode 100644 seed/php-sdk/server-sent-events/src/Core/BaseApiRequest.php
 create mode 100644 seed/php-sdk/server-sent-events/src/Core/Constant.php
 create mode 100644 seed/php-sdk/server-sent-events/src/Core/DateType.php
 create mode 100644 seed/php-sdk/server-sent-events/src/Core/HttpMethod.php
 create mode 100644 seed/php-sdk/server-sent-events/src/Core/JsonApiRequest.php
 create mode 100644 seed/php-sdk/server-sent-events/src/Core/JsonDecoder.php
 create mode 100644 seed/php-sdk/server-sent-events/src/Core/JsonDeserializer.php
 create mode 100644 seed/php-sdk/server-sent-events/src/Core/JsonEncoder.php
 create mode 100644 seed/php-sdk/server-sent-events/src/Core/JsonProperty.php
 create mode 100644 seed/php-sdk/server-sent-events/src/Core/JsonSerializer.php
 create mode 100644 seed/php-sdk/server-sent-events/src/Core/RawClient.php
 create mode 100644 seed/php-sdk/server-sent-events/src/Core/SerializableType.php
 create mode 100644 seed/php-sdk/server-sent-events/src/Core/Union.php
 create mode 100644 seed/php-sdk/server-sent-events/src/Core/Utils.php
 create mode 100644 seed/php-sdk/server-sent-events/src/Exceptions/SeedApiException.php
 create mode 100644 seed/php-sdk/server-sent-events/src/Exceptions/SeedException.php
 create mode 100644 seed/php-sdk/server-sent-events/src/SeedClient.php
 create mode 100644 seed/php-sdk/server-sent-events/tests/Seed/Core/DateArrayTypeTest.php
 create mode 100644 seed/php-sdk/server-sent-events/tests/Seed/Core/EmptyArraysTest.php
 create mode 100644 seed/php-sdk/server-sent-events/tests/Seed/Core/EnumTest.php
 create mode 100644 seed/php-sdk/server-sent-events/tests/Seed/Core/InvalidTypesTest.php
 create mode 100644 seed/php-sdk/server-sent-events/tests/Seed/Core/MixedDateArrayTypeTest.php
 create mode 100644 seed/php-sdk/server-sent-events/tests/Seed/Core/NestedUnionArrayTypeTest.php
 create mode 100644 seed/php-sdk/server-sent-events/tests/Seed/Core/NullPropertyTypeTest.php
 create mode 100644 seed/php-sdk/server-sent-events/tests/Seed/Core/NullableArrayTypeTest.php
 create mode 100644 seed/php-sdk/server-sent-events/tests/Seed/Core/RawClientTest.php
 create mode 100644 seed/php-sdk/server-sent-events/tests/Seed/Core/ScalarTypesTest.php
 create mode 100644 seed/php-sdk/server-sent-events/tests/Seed/Core/TestTypeTest.php
 create mode 100644 seed/php-sdk/server-sent-events/tests/Seed/Core/UnionArrayTypeTest.php
 create mode 100644 seed/python-sdk/server-sent-events/resolved-snippet-templates.md
 delete mode 100644 seed/ruby-sdk/server-sent-events/lib/fern_server_sent_events/completions/client.rb
 delete mode 100644 seed/ruby-sdk/server-sent-events/lib/requests.rb
 delete mode 100644 seed/ruby-sdk/server-sent-events/lib/types_export.rb
 create mode 100644 seed/ts-sdk/server-sent-events/jest.config.js
 create mode 100644 seed/ts-sdk/server-sent-events/resolved-snippet-templates.md
 create mode 100644 seed/ts-sdk/server-sent-events/src/core/schemas/builders/bigint/bigint.ts
 create mode 100644 seed/ts-sdk/server-sent-events/src/core/schemas/builders/bigint/index.ts
 create mode 100644 seed/ts-sdk/server-sent-events/src/version.ts
 create mode 100644 seed/ts-sdk/server-sent-events/tests/unit/fetcher/stream-wrappers/webpack.test.ts
 create mode 100644 seed/ts-sdk/server-sent-events/tests/unit/zurg/bigint/bigint.test.ts

diff --git a/seed/csharp-model/server-sent-events/.gitignore b/seed/csharp-model/server-sent-events/.gitignore
index 9965de29662..5e57f18055d 100644
--- a/seed/csharp-model/server-sent-events/.gitignore
+++ b/seed/csharp-model/server-sent-events/.gitignore
@@ -1,7 +1,10 @@
 ## Ignore Visual Studio temporary files, build results, and
 ## files generated by popular Visual Studio add-ons.
 ##
-## Get latest from https://github.com/github/gitignore/blob/main/VisualStudio.gitignore
+## Get latest from `dotnet new gitignore`
+
+# dotenv files
+.env
 
 # User-specific files
 *.rsuser
@@ -399,6 +402,7 @@ FodyWeavers.xsd
 
 # JetBrains Rider
 *.sln.iml
+.idea
 
 ##
 ## Visual studio for Mac
@@ -475,3 +479,6 @@ $RECYCLE.BIN/
 
 # Windows shortcuts
 *.lnk
+
+# Vim temporary swap files
+*.swp
diff --git a/seed/csharp-model/server-sent-events/src/SeedServerSentEvents.Test/SeedServerSentEvents.Test.csproj b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents.Test/SeedServerSentEvents.Test.csproj
index 31335ba802f..7fa553ecb76 100644
--- a/seed/csharp-model/server-sent-events/src/SeedServerSentEvents.Test/SeedServerSentEvents.Test.csproj
+++ b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents.Test/SeedServerSentEvents.Test.csproj
@@ -15,6 +15,8 @@
         <PackageReference Include="NUnit3TestAdapter" Version="4.4.2"/>
         <PackageReference Include="NUnit.Analyzers" Version="3.6.1"/>
         <PackageReference Include="coverlet.collector" Version="3.2.0"/>
+        <PackageReference Include="WireMock.Net" Version="1.5.60" />
+        <PackageReference Include="FluentAssertions.Json" Version="6.1.0" />
     </ItemGroup>
 
     <ItemGroup>
diff --git a/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Completions/StreamedCompletion.cs b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Completions/StreamedCompletion.cs
index 108d0ed7e69..42b2117e3c2 100644
--- a/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Completions/StreamedCompletion.cs
+++ b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Completions/StreamedCompletion.cs
@@ -1,4 +1,5 @@
 using System.Text.Json.Serialization;
+using SeedServerSentEvents.Core;
 
 #nullable enable
 
@@ -11,4 +12,9 @@ public record StreamedCompletion
 
     [JsonPropertyName("tokens")]
     public int? Tokens { get; set; }
+
+    public override string ToString()
+    {
+        return JsonUtils.Serialize(this);
+    }
 }
diff --git a/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/CollectionItemSerializer.cs b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/CollectionItemSerializer.cs
index 46753a77c5a..98010900521 100644
--- a/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/CollectionItemSerializer.cs
+++ b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/CollectionItemSerializer.cs
@@ -10,7 +10,7 @@ namespace SeedServerSentEvents.Core;
 /// </summary>
 /// <typeparam name="TDatatype">Type of item to convert.</typeparam>
 /// <typeparam name="TConverterType">Converter to use for individual items.</typeparam>
-public class CollectionItemSerializer<TDatatype, TConverterType>
+internal class CollectionItemSerializer<TDatatype, TConverterType>
     : JsonConverter<IEnumerable<TDatatype>>
     where TConverterType : JsonConverter
 {
diff --git a/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/Constants.cs b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/Constants.cs
new file mode 100644
index 00000000000..44b6ee86fcc
--- /dev/null
+++ b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/Constants.cs
@@ -0,0 +1,7 @@
+namespace SeedServerSentEvents.Core;
+
+internal static class Constants
+{
+    public const string DateTimeFormat = "yyyy'-'MM'-'dd'T'HH':'mm':'ss.fffK";
+    public const string DateFormat = "yyyy-MM-dd";
+}
diff --git a/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/DateTimeSerializer.cs b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/DateTimeSerializer.cs
new file mode 100644
index 00000000000..2dd35f4ec96
--- /dev/null
+++ b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/DateTimeSerializer.cs
@@ -0,0 +1,22 @@
+using System.Globalization;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace SeedServerSentEvents.Core;
+
+internal class DateTimeSerializer : JsonConverter<DateTime>
+{
+    public override DateTime Read(
+        ref Utf8JsonReader reader,
+        System.Type typeToConvert,
+        JsonSerializerOptions options
+    )
+    {
+        return DateTime.Parse(reader.GetString()!, null, DateTimeStyles.RoundtripKind);
+    }
+
+    public override void Write(Utf8JsonWriter writer, DateTime value, JsonSerializerOptions options)
+    {
+        writer.WriteStringValue(value.ToString(Constants.DateTimeFormat));
+    }
+}
diff --git a/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/JsonConfiguration.cs b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/JsonConfiguration.cs
new file mode 100644
index 00000000000..4e016a1bb3b
--- /dev/null
+++ b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/JsonConfiguration.cs
@@ -0,0 +1,32 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace SeedServerSentEvents.Core;
+
+internal static class JsonOptions
+{
+    public static readonly JsonSerializerOptions JsonSerializerOptions;
+
+    static JsonOptions()
+    {
+        JsonSerializerOptions = new JsonSerializerOptions
+        {
+            Converters = { new DateTimeSerializer(), new OneOfSerializer() },
+            WriteIndented = true,
+            DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
+        };
+    }
+}
+
+internal static class JsonUtils
+{
+    public static string Serialize<T>(T obj)
+    {
+        return JsonSerializer.Serialize(obj, JsonOptions.JsonSerializerOptions);
+    }
+
+    public static T Deserialize<T>(string json)
+    {
+        return JsonSerializer.Deserialize<T>(json, JsonOptions.JsonSerializerOptions)!;
+    }
+}
diff --git a/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/OneOfSerializer.cs b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/OneOfSerializer.cs
index fb6caa0f90f..71b9dbcc630 100644
--- a/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/OneOfSerializer.cs
+++ b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/OneOfSerializer.cs
@@ -5,10 +5,9 @@
 
 namespace SeedServerSentEvents.Core;
 
-public class OneOfSerializer<TOneOf> : JsonConverter<TOneOf>
-    where TOneOf : IOneOf
+internal class OneOfSerializer : JsonConverter<IOneOf>
 {
-    public override TOneOf? Read(
+    public override IOneOf? Read(
         ref Utf8JsonReader reader,
         System.Type typeToConvert,
         JsonSerializerOptions options
@@ -17,14 +16,14 @@ JsonSerializerOptions options
         if (reader.TokenType is JsonTokenType.Null)
             return default;
 
-        foreach (var (type, cast) in s_types)
+        foreach (var (type, cast) in GetOneOfTypes(typeToConvert))
         {
             try
             {
                 var readerCopy = reader;
                 var result = JsonSerializer.Deserialize(ref readerCopy, type, options);
                 reader.Skip();
-                return (TOneOf)cast.Invoke(null, [result])!;
+                return (IOneOf)cast.Invoke(null, [result])!;
             }
             catch (JsonException) { }
         }
@@ -34,20 +33,18 @@ JsonSerializerOptions options
         );
     }
 
-    private static readonly (System.Type type, MethodInfo cast)[] s_types = GetOneOfTypes();
-
-    public override void Write(Utf8JsonWriter writer, TOneOf value, JsonSerializerOptions options)
+    public override void Write(Utf8JsonWriter writer, IOneOf value, JsonSerializerOptions options)
     {
         JsonSerializer.Serialize(writer, value.Value, options);
     }
 
-    private static (System.Type type, MethodInfo cast)[] GetOneOfTypes()
+    private static (System.Type type, MethodInfo cast)[] GetOneOfTypes(System.Type typeToConvert)
     {
-        var casts = typeof(TOneOf)
+        var casts = typeToConvert
             .GetRuntimeMethods()
             .Where(m => m.IsSpecialName && m.Name == "op_Implicit")
             .ToArray();
-        var type = typeof(TOneOf);
+        var type = typeToConvert;
         while (type != null)
         {
             if (
@@ -62,6 +59,11 @@ private static (System.Type type, MethodInfo cast)[] GetOneOfTypes()
 
             type = type.BaseType;
         }
-        throw new InvalidOperationException($"{typeof(TOneOf)} isn't OneOf or OneOfBase");
+        throw new InvalidOperationException($"{type} isn't OneOf or OneOfBase");
+    }
+
+    public override bool CanConvert(System.Type typeToConvert)
+    {
+        return typeof(IOneOf).IsAssignableFrom(typeToConvert);
     }
 }
diff --git a/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/Public/Version.cs b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/Public/Version.cs
new file mode 100644
index 00000000000..8296b59ade5
--- /dev/null
+++ b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/Public/Version.cs
@@ -0,0 +1,6 @@
+namespace SeedServerSentEvents;
+
+internal class Version
+{
+    public const string Current = "0.0.1";
+}
diff --git a/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/StringEnumSerializer.cs b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/StringEnumSerializer.cs
index 143654892f7..707a72f31b4 100644
--- a/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/StringEnumSerializer.cs
+++ b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/Core/StringEnumSerializer.cs
@@ -4,7 +4,7 @@
 
 namespace SeedServerSentEvents.Core;
 
-public class StringEnumSerializer<TEnum> : JsonConverter<TEnum>
+internal class StringEnumSerializer<TEnum> : JsonConverter<TEnum>
     where TEnum : struct, System.Enum
 {
     private readonly Dictionary<TEnum, string> _enumToString = new();
diff --git a/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/SeedServerSentEvents.csproj b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/SeedServerSentEvents.csproj
index 11f735b98cc..dfaed0b7562 100644
--- a/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/SeedServerSentEvents.csproj
+++ b/seed/csharp-model/server-sent-events/src/SeedServerSentEvents/SeedServerSentEvents.csproj
@@ -11,7 +11,7 @@
         <PackageReadmeFile>README.md</PackageReadmeFile>
         <PackageProjectUrl>https://github.com/server-sent-events/fern</PackageProjectUrl>
     </PropertyGroup>
-    
+
     <PropertyGroup Condition="'$(TargetFramework)' == 'net6.0' Or '$(TargetFramework)' == 'net462' Or '$(TargetFramework)' == 'netstandard2.0'">
         <PolySharpIncludeRuntimeSupportedAttributes>true</PolySharpIncludeRuntimeSupportedAttributes>
     </PropertyGroup>
@@ -41,5 +41,10 @@
         <None Include="..\..\README.md" Pack="true" PackagePath=""/>
     </ItemGroup>
 
+    <ItemGroup>
+        <AssemblyAttribute Include="System.Runtime.CompilerServices.InternalsVisibleTo">
+            <_Parameter1>SeedServerSentEvents.Test</_Parameter1>
+        </AssemblyAttribute>
+    </ItemGroup>
 
 </Project>
diff --git a/seed/csharp-sdk/server-sent-events/README.md b/seed/csharp-sdk/server-sent-events/README.md
new file mode 100644
index 00000000000..91c010b022f
--- /dev/null
+++ b/seed/csharp-sdk/server-sent-events/README.md
@@ -0,0 +1,87 @@
+# Seed C# Library
+
+[![fern shield](https://img.shields.io/badge/%F0%9F%8C%BF-Built%20with%20Fern-brightgreen)](https://buildwithfern.com?utm_source=github&utm_medium=github&utm_campaign=readme&utm_source=Seed%2FC%23)
+[![nuget shield](https://img.shields.io/nuget/v/SeedServerSentEvents)](https://nuget.org/packages/SeedServerSentEvents)
+
+The Seed C# library provides convenient access to the Seed API from C#.
+
+## Installation
+
+```sh
+nuget install SeedServerSentEvents
+```
+
+## Usage
+
+Instantiate and use the client with the following:
+
+```csharp
+using SeedServerSentEvents;
+
+var client = new SeedServerSentEventsClient();
+await client.Completions.StreamAsync(new StreamCompletionRequest { Query = "string" });
+```
+
+## Exception Handling
+
+When the API returns a non-success status code (4xx or 5xx response), a subclass of the following error
+will be thrown.
+
+```csharp
+using SeedServerSentEvents;
+
+try {
+    var response = await client.Completions.StreamAsync(...);
+} catch (SeedServerSentEventsApiException e) {
+    System.Console.WriteLine(e.Body);
+    System.Console.WriteLine(e.StatusCode);
+}
+```
+
+## Advanced
+
+### Retries
+
+The SDK is instrumented with automatic retries with exponential backoff. A request will be retried as long
+as the request is deemed retriable and the number of retry attempts has not grown larger than the configured
+retry limit (default: 2).
+
+A request is deemed retriable when any of the following HTTP status codes is returned:
+
+- [408](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/408) (Timeout)
+- [429](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/429) (Too Many Requests)
+- [5XX](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/500) (Internal Server Errors)
+
+Use the `MaxRetries` request option to configure this behavior.
+
+```csharp
+var response = await client.Completions.StreamAsync(
+    ...,
+    new RequestOptions {
+        MaxRetries: 0 // Override MaxRetries at the request level
+    }
+);
+```
+
+### Timeouts
+
+The SDK defaults to a 30 second timeout. Use the `Timeout` option to configure this behavior.
+
+```csharp
+var response = await client.Completions.StreamAsync(
+    ...,
+    new RequestOptions {
+        Timeout: TimeSpan.FromSeconds(3) // Override timeout to 3s
+    }
+);
+```
+
+## Contributing
+
+While we value open-source contributions to this SDK, this library is generated programmatically.
+Additions made directly to this library would have to be moved over to our generation code,
+otherwise they would be overwritten upon the next generated release. Feel free to open a PR as
+a proof of concept, but know that we will not be able to merge it as-is. We suggest opening
+an issue first to discuss with us!
+
+On the other hand, contributions to the README are always very welcome!
\ No newline at end of file
diff --git a/seed/csharp-sdk/server-sent-events/reference.md b/seed/csharp-sdk/server-sent-events/reference.md
new file mode 100644
index 00000000000..76ccc7a0adf
--- /dev/null
+++ b/seed/csharp-sdk/server-sent-events/reference.md
@@ -0,0 +1,41 @@
+# Reference
+## Completions
+<details><summary><code>client.Completions.<a href="/src/SeedServerSentEvents/Completions/CompletionsClient.cs">StreamAsync</a>(StreamCompletionRequest { ... })</code></summary>
+<dl>
+<dd>
+
+#### 🔌 Usage
+
+<dl>
+<dd>
+
+<dl>
+<dd>
+
+```csharp
+await client.Completions.StreamAsync(new StreamCompletionRequest { Query = "string" });
+```
+</dd>
+</dl>
+</dd>
+</dl>
+
+#### ⚙️ Parameters
+
+<dl>
+<dd>
+
+<dl>
+<dd>
+
+**request:** `StreamCompletionRequest` 
+    
+</dd>
+</dl>
+</dd>
+</dl>
+
+
+</dd>
+</dl>
+</details>
diff --git a/seed/csharp-sdk/server-sent-events/snippet-templates.json b/seed/csharp-sdk/server-sent-events/snippet-templates.json
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/seed/csharp-sdk/server-sent-events/snippet.json b/seed/csharp-sdk/server-sent-events/snippet.json
new file mode 100644
index 00000000000..ad0e1d38051
--- /dev/null
+++ b/seed/csharp-sdk/server-sent-events/snippet.json
@@ -0,0 +1,17 @@
+{
+    "types": {},
+    "endpoints": [
+        {
+            "example_identifier": null,
+            "id": {
+                "path": "/stream",
+                "method": "POST",
+                "identifier_override": "endpoint_completions.stream"
+            },
+            "snippet": {
+                "type": "typescript",
+                "client": "using SeedServerSentEvents;\n\nvar client = new SeedServerSentEventsClient();\nawait client.Completions.StreamAsync(new StreamCompletionRequest { Query = \"string\" });\n"
+            }
+        }
+    ]
+}
\ No newline at end of file
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents.Test/Core/RawClientTests.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents.Test/Core/RawClientTests.cs
new file mode 100644
index 00000000000..42f412c3b10
--- /dev/null
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents.Test/Core/RawClientTests.cs
@@ -0,0 +1,113 @@
+using System;
+using System.Net.Http;
+using FluentAssertions;
+using NUnit.Framework;
+using SeedServerSentEvents.Core;
+using WireMock.Server;
+using SystemTask = System.Threading.Tasks.Task;
+using WireMockRequest = WireMock.RequestBuilders.Request;
+using WireMockResponse = WireMock.ResponseBuilders.Response;
+
+namespace SeedServerSentEvents.Test.Core
+{
+    [TestFixture]
+    public class RawClientTests
+    {
+        private WireMockServer _server;
+        private HttpClient _httpClient;
+        private RawClient _rawClient;
+        private string _baseUrl;
+        private const int _maxRetries = 3;
+
+        [SetUp]
+        public void SetUp()
+        {
+            _server = WireMockServer.Start();
+            _baseUrl = _server.Url ?? "";
+            _httpClient = new HttpClient { BaseAddress = new Uri(_baseUrl) };
+            _rawClient = new RawClient(
+                new ClientOptions() { HttpClient = _httpClient, MaxRetries = _maxRetries }
+            );
+        }
+
+        [Test]
+        [TestCase(408)]
+        [TestCase(429)]
+        [TestCase(500)]
+        [TestCase(504)]
+        public async SystemTask MakeRequestAsync_ShouldRetry_OnRetryableStatusCodes(int statusCode)
+        {
+            _server
+                .Given(WireMockRequest.Create().WithPath("/test").UsingGet())
+                .InScenario("Retry")
+                .WillSetStateTo("Server Error")
+                .RespondWith(WireMockResponse.Create().WithStatusCode(statusCode));
+
+            _server
+                .Given(WireMockRequest.Create().WithPath("/test").UsingGet())
+                .InScenario("Retry")
+                .WhenStateIs("Server Error")
+                .WillSetStateTo("Success")
+                .RespondWith(WireMockResponse.Create().WithStatusCode(statusCode));
+
+            _server
+                .Given(WireMockRequest.Create().WithPath("/test").UsingGet())
+                .InScenario("Retry")
+                .WhenStateIs("Success")
+                .RespondWith(WireMockResponse.Create().WithStatusCode(200).WithBody("Success"));
+
+            var request = new RawClient.BaseApiRequest
+            {
+                BaseUrl = _baseUrl,
+                Method = HttpMethod.Get,
+                Path = "/test",
+            };
+
+            var response = await _rawClient.MakeRequestAsync(request);
+            Assert.That(response.StatusCode, Is.EqualTo(200));
+
+            var content = await response.Raw.Content.ReadAsStringAsync();
+            Assert.That(content, Is.EqualTo("Success"));
+
+            Assert.That(_server.LogEntries.Count, Is.EqualTo(_maxRetries));
+        }
+
+        [Test]
+        [TestCase(400)]
+        [TestCase(409)]
+        public async SystemTask MakeRequestAsync_ShouldRetry_OnNonRetryableStatusCodes(
+            int statusCode
+        )
+        {
+            _server
+                .Given(WireMockRequest.Create().WithPath("/test").UsingGet())
+                .InScenario("Retry")
+                .WillSetStateTo("Server Error")
+                .RespondWith(
+                    WireMockResponse.Create().WithStatusCode(statusCode).WithBody("Failure")
+                );
+
+            var request = new RawClient.BaseApiRequest
+            {
+                BaseUrl = _baseUrl,
+                Method = HttpMethod.Get,
+                Path = "/test",
+            };
+
+            var response = await _rawClient.MakeRequestAsync(request);
+            Assert.That(response.StatusCode, Is.EqualTo(statusCode));
+
+            var content = await response.Raw.Content.ReadAsStringAsync();
+            Assert.That(content, Is.EqualTo("Failure"));
+
+            Assert.That(_server.LogEntries.Count, Is.EqualTo(1));
+        }
+
+        [TearDown]
+        public void TearDown()
+        {
+            _server.Dispose();
+            _httpClient.Dispose();
+        }
+    }
+}
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents.Test/SeedServerSentEvents.Test.csproj b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents.Test/SeedServerSentEvents.Test.csproj
index 5988c7f8c42..7fa553ecb76 100644
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents.Test/SeedServerSentEvents.Test.csproj
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents.Test/SeedServerSentEvents.Test.csproj
@@ -16,6 +16,7 @@
         <PackageReference Include="NUnit.Analyzers" Version="3.6.1"/>
         <PackageReference Include="coverlet.collector" Version="3.2.0"/>
         <PackageReference Include="WireMock.Net" Version="1.5.60" />
+        <PackageReference Include="FluentAssertions.Json" Version="6.1.0" />
     </ItemGroup>
 
     <ItemGroup>
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents.Test/Utils/JsonDiffChecker.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents.Test/Utils/JsonDiffChecker.cs
deleted file mode 100644
index 8542d7fd40c..00000000000
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents.Test/Utils/JsonDiffChecker.cs
+++ /dev/null
@@ -1,85 +0,0 @@
-using Newtonsoft.Json.Linq;
-using NUnit.Framework;
-
-namespace SeedServerSentEvents.Test.Utils;
-
-public static class JsonDiffChecker
-{
-    public static void AssertJsonEquals(string jsonString1, string jsonString2)
-    {
-        var token1 = JToken.Parse(jsonString1);
-        var token2 = JToken.Parse(jsonString2);
-        var differences = GetJsonDifferences(token1, token2);
-
-        Assert.That(
-            differences,
-            Is.Empty,
-            $"The JSON strings are not equal: {string.Join(", ", differences)}"
-        );
-    }
-
-    private static List<string> GetJsonDifferences(JToken token1, JToken token2, string path = "")
-    {
-        var differences = new List<string>();
-
-        if (token1.Type != token2.Type)
-        {
-            differences.Add($"{path} has different types: {token1.Type} vs {token2.Type}");
-            return differences;
-        }
-
-        if (token1 is JObject obj1 && token2 is JObject obj2)
-        {
-            foreach (var property in obj1.Properties())
-            {
-                var newPath = string.IsNullOrEmpty(path)
-                    ? property.Name
-                    : $"{path}.{property.Name}";
-                if (!obj2.TryGetValue(property.Name, out JToken token2Value))
-                {
-                    differences.Add($"{newPath} is missing in the second JSON");
-                }
-                else
-                {
-                    differences.AddRange(GetJsonDifferences(property.Value, token2Value, newPath));
-                }
-            }
-
-            foreach (var property in obj2.Properties())
-            {
-                var newPath = string.IsNullOrEmpty(path)
-                    ? property.Name
-                    : $"{path}.{property.Name}";
-                if (!obj1.TryGetValue(property.Name, out _))
-                {
-                    differences.Add($"{newPath} is missing in the first JSON");
-                }
-            }
-        }
-        else if (token1 is JArray array1 && token2 is JArray array2)
-        {
-            for (var i = 0; i < Math.Max(array1.Count, array2.Count); i++)
-            {
-                var newPath = $"{path}[{i}]";
-                if (i >= array1.Count)
-                {
-                    differences.Add($"{newPath} is missing in the first JSON");
-                }
-                else if (i >= array2.Count)
-                {
-                    differences.Add($"{newPath} is missing in the second JSON");
-                }
-                else
-                {
-                    differences.AddRange(GetJsonDifferences(array1[i], array2[i], newPath));
-                }
-            }
-        }
-        else if (!JToken.DeepEquals(token1, token2))
-        {
-            differences.Add($"{path} has different values: {token1} vs {token2}");
-        }
-
-        return differences;
-    }
-}
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents.Test/Wire/BaseWireTest.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents.Test/Wire/BaseWireTest.cs
deleted file mode 100644
index 73cd5c96c11..00000000000
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents.Test/Wire/BaseWireTest.cs
+++ /dev/null
@@ -1,36 +0,0 @@
-using NUnit.Framework;
-using SeedServerSentEvents;
-using SeedServerSentEvents.Core;
-using WireMock.Logging;
-using WireMock.Server;
-using WireMock.Settings;
-
-#nullable enable
-
-namespace SeedServerSentEvents.Test.Wire;
-
-[SetUpFixture]
-public class BaseWireTest
-{
-    protected static WireMockServer Server { get; set; } = null!;
-
-    protected static SeedServerSentEventsClient Client { get; set; } = null!;
-
-    [OneTimeSetUp]
-    public void GlobalSetup()
-    {
-        // Start the WireMock server
-        Server = WireMockServer.Start(
-            new WireMockServerSettings { Logger = new WireMockConsoleLogger() }
-        );
-
-        // Initialize the Client
-        Client = new SeedServerSentEventsClient(new ClientOptions { BaseUrl = Server.Urls[0] });
-    }
-
-    [OneTimeTearDown]
-    public void GlobalTeardown()
-    {
-        Server.Stop();
-    }
-}
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Completions/CompletionsClient.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Completions/CompletionsClient.cs
index 67703a6bded..19c515299ed 100644
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Completions/CompletionsClient.cs
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Completions/CompletionsClient.cs
@@ -1,21 +1,31 @@
 using System.Net.Http;
-using SeedServerSentEvents;
+using System.Threading;
+using System.Threading.Tasks;
 using SeedServerSentEvents.Core;
 
 #nullable enable
 
 namespace SeedServerSentEvents;
 
-public class CompletionsClient
+public partial class CompletionsClient
 {
     private RawClient _client;
 
-    public CompletionsClient(RawClient client)
+    internal CompletionsClient(RawClient client)
     {
         _client = client;
     }
 
-    public async Task StreamAsync(StreamCompletionRequest request, RequestOptions? options = null)
+    /// <example>
+    /// <code>
+    /// await client.Completions.StreamAsync(new StreamCompletionRequest { Query = "string" });
+    /// </code>
+    /// </example>
+    public async Task StreamAsync(
+        StreamCompletionRequest request,
+        RequestOptions? options = null,
+        CancellationToken cancellationToken = default
+    )
     {
         var response = await _client.MakeRequestAsync(
             new RawClient.JsonApiRequest
@@ -24,14 +34,15 @@ public async Task StreamAsync(StreamCompletionRequest request, RequestOptions? o
                 Method = HttpMethod.Post,
                 Path = "stream",
                 Body = request,
-                Options = options
-            }
+                Options = options,
+            },
+            cancellationToken
         );
         var responseBody = await response.Raw.Content.ReadAsStringAsync();
         throw new SeedServerSentEventsApiException(
             $"Error with status code {response.StatusCode}",
             response.StatusCode,
-            JsonUtils.Deserialize<object>(responseBody)
+            responseBody
         );
     }
 }
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Completions/Requests/StreamCompletionRequest.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Completions/Requests/StreamCompletionRequest.cs
index 44558dbe087..3d5461dd219 100644
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Completions/Requests/StreamCompletionRequest.cs
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Completions/Requests/StreamCompletionRequest.cs
@@ -1,4 +1,5 @@
 using System.Text.Json.Serialization;
+using SeedServerSentEvents.Core;
 
 #nullable enable
 
@@ -8,4 +9,9 @@ public record StreamCompletionRequest
 {
     [JsonPropertyName("query")]
     public required string Query { get; set; }
+
+    public override string ToString()
+    {
+        return JsonUtils.Serialize(this);
+    }
 }
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Completions/Types/StreamedCompletion.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Completions/Types/StreamedCompletion.cs
index 108d0ed7e69..42b2117e3c2 100644
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Completions/Types/StreamedCompletion.cs
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Completions/Types/StreamedCompletion.cs
@@ -1,4 +1,5 @@
 using System.Text.Json.Serialization;
+using SeedServerSentEvents.Core;
 
 #nullable enable
 
@@ -11,4 +12,9 @@ public record StreamedCompletion
 
     [JsonPropertyName("tokens")]
     public int? Tokens { get; set; }
+
+    public override string ToString()
+    {
+        return JsonUtils.Serialize(this);
+    }
 }
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/CollectionItemSerializer.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/CollectionItemSerializer.cs
index 46753a77c5a..98010900521 100644
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/CollectionItemSerializer.cs
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/CollectionItemSerializer.cs
@@ -10,7 +10,7 @@ namespace SeedServerSentEvents.Core;
 /// </summary>
 /// <typeparam name="TDatatype">Type of item to convert.</typeparam>
 /// <typeparam name="TConverterType">Converter to use for individual items.</typeparam>
-public class CollectionItemSerializer<TDatatype, TConverterType>
+internal class CollectionItemSerializer<TDatatype, TConverterType>
     : JsonConverter<IEnumerable<TDatatype>>
     where TConverterType : JsonConverter
 {
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Constants.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Constants.cs
index 2b6193397eb..44b6ee86fcc 100644
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Constants.cs
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Constants.cs
@@ -1,6 +1,7 @@
 namespace SeedServerSentEvents.Core;
 
-public static class Constants
+internal static class Constants
 {
     public const string DateTimeFormat = "yyyy'-'MM'-'dd'T'HH':'mm':'ss.fffK";
+    public const string DateFormat = "yyyy-MM-dd";
 }
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/DateTimeSerializer.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/DateTimeSerializer.cs
index 5c4e6d31960..2dd35f4ec96 100644
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/DateTimeSerializer.cs
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/DateTimeSerializer.cs
@@ -4,7 +4,7 @@
 
 namespace SeedServerSentEvents.Core;
 
-public class DateTimeSerializer : JsonConverter<DateTime>
+internal class DateTimeSerializer : JsonConverter<DateTime>
 {
     public override DateTime Read(
         ref Utf8JsonReader reader,
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Extensions.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Extensions.cs
new file mode 100644
index 00000000000..0ecf7b52315
--- /dev/null
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Extensions.cs
@@ -0,0 +1,14 @@
+using System.Runtime.Serialization;
+
+namespace SeedServerSentEvents.Core;
+
+internal static class Extensions
+{
+    public static string Stringify(this Enum value)
+    {
+        var field = value.GetType().GetField(value.ToString());
+        var attribute = (EnumMemberAttribute)
+            Attribute.GetCustomAttribute(field, typeof(EnumMemberAttribute));
+        return attribute?.Value ?? value.ToString();
+    }
+}
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/HeaderValue.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/HeaderValue.cs
new file mode 100644
index 00000000000..dfaba92fec5
--- /dev/null
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/HeaderValue.cs
@@ -0,0 +1,17 @@
+using OneOf;
+
+namespace SeedServerSentEvents.Core;
+
+internal sealed class HeaderValue(OneOf<string, Func<string>> value)
+    : OneOfBase<string, Func<string>>(value)
+{
+    public static implicit operator HeaderValue(string value)
+    {
+        return new HeaderValue(value);
+    }
+
+    public static implicit operator HeaderValue(Func<string> value)
+    {
+        return new HeaderValue(value);
+    }
+}
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Headers.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Headers.cs
new file mode 100644
index 00000000000..9d919f4428e
--- /dev/null
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Headers.cs
@@ -0,0 +1,17 @@
+namespace SeedServerSentEvents.Core;
+
+internal sealed class Headers : Dictionary<string, HeaderValue>
+{
+    public Headers() { }
+
+    public Headers(Dictionary<string, string> value)
+    {
+        foreach (var kvp in value)
+        {
+            this[kvp.Key] = new HeaderValue(kvp.Value);
+        }
+    }
+
+    public Headers(IEnumerable<KeyValuePair<string, HeaderValue>> value)
+        : base(value.ToDictionary(e => e.Key, e => e.Value)) { }
+}
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/HttpMethodExtensions.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/HttpMethodExtensions.cs
index b260d85c623..2ff0ab00192 100644
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/HttpMethodExtensions.cs
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/HttpMethodExtensions.cs
@@ -2,7 +2,7 @@
 
 namespace SeedServerSentEvents.Core;
 
-public static class HttpMethodExtensions
+internal static class HttpMethodExtensions
 {
     public static readonly HttpMethod Patch = new("PATCH");
 }
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/JsonConfiguration.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/JsonConfiguration.cs
index d33a62e34f7..4e016a1bb3b 100644
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/JsonConfiguration.cs
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/JsonConfiguration.cs
@@ -3,7 +3,7 @@
 
 namespace SeedServerSentEvents.Core;
 
-public static class JsonOptions
+internal static class JsonOptions
 {
     public static readonly JsonSerializerOptions JsonSerializerOptions;
 
@@ -11,14 +11,14 @@ static JsonOptions()
     {
         JsonSerializerOptions = new JsonSerializerOptions
         {
-            Converters = { new DateTimeSerializer() },
+            Converters = { new DateTimeSerializer(), new OneOfSerializer() },
             WriteIndented = true,
-            DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull
+            DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
         };
     }
 }
 
-public static class JsonUtils
+internal static class JsonUtils
 {
     public static string Serialize<T>(T obj)
     {
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/OneOfSerializer.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/OneOfSerializer.cs
index fb6caa0f90f..71b9dbcc630 100644
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/OneOfSerializer.cs
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/OneOfSerializer.cs
@@ -5,10 +5,9 @@
 
 namespace SeedServerSentEvents.Core;
 
-public class OneOfSerializer<TOneOf> : JsonConverter<TOneOf>
-    where TOneOf : IOneOf
+internal class OneOfSerializer : JsonConverter<IOneOf>
 {
-    public override TOneOf? Read(
+    public override IOneOf? Read(
         ref Utf8JsonReader reader,
         System.Type typeToConvert,
         JsonSerializerOptions options
@@ -17,14 +16,14 @@ JsonSerializerOptions options
         if (reader.TokenType is JsonTokenType.Null)
             return default;
 
-        foreach (var (type, cast) in s_types)
+        foreach (var (type, cast) in GetOneOfTypes(typeToConvert))
         {
             try
             {
                 var readerCopy = reader;
                 var result = JsonSerializer.Deserialize(ref readerCopy, type, options);
                 reader.Skip();
-                return (TOneOf)cast.Invoke(null, [result])!;
+                return (IOneOf)cast.Invoke(null, [result])!;
             }
             catch (JsonException) { }
         }
@@ -34,20 +33,18 @@ JsonSerializerOptions options
         );
     }
 
-    private static readonly (System.Type type, MethodInfo cast)[] s_types = GetOneOfTypes();
-
-    public override void Write(Utf8JsonWriter writer, TOneOf value, JsonSerializerOptions options)
+    public override void Write(Utf8JsonWriter writer, IOneOf value, JsonSerializerOptions options)
     {
         JsonSerializer.Serialize(writer, value.Value, options);
     }
 
-    private static (System.Type type, MethodInfo cast)[] GetOneOfTypes()
+    private static (System.Type type, MethodInfo cast)[] GetOneOfTypes(System.Type typeToConvert)
     {
-        var casts = typeof(TOneOf)
+        var casts = typeToConvert
             .GetRuntimeMethods()
             .Where(m => m.IsSpecialName && m.Name == "op_Implicit")
             .ToArray();
-        var type = typeof(TOneOf);
+        var type = typeToConvert;
         while (type != null)
         {
             if (
@@ -62,6 +59,11 @@ private static (System.Type type, MethodInfo cast)[] GetOneOfTypes()
 
             type = type.BaseType;
         }
-        throw new InvalidOperationException($"{typeof(TOneOf)} isn't OneOf or OneOfBase");
+        throw new InvalidOperationException($"{type} isn't OneOf or OneOfBase");
+    }
+
+    public override bool CanConvert(System.Type typeToConvert)
+    {
+        return typeof(IOneOf).IsAssignableFrom(typeToConvert);
     }
 }
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/ClientOptions.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Public/ClientOptions.cs
similarity index 75%
rename from seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/ClientOptions.cs
rename to seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Public/ClientOptions.cs
index 302ec64fd21..85fde994e61 100644
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/ClientOptions.cs
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Public/ClientOptions.cs
@@ -1,9 +1,10 @@
 using System;
 using System.Net.Http;
+using SeedServerSentEvents.Core;
 
 #nullable enable
 
-namespace SeedServerSentEvents.Core;
+namespace SeedServerSentEvents;
 
 public partial class ClientOptions
 {
@@ -26,4 +27,9 @@ public partial class ClientOptions
     /// The timeout for the request.
     /// </summary>
     public TimeSpan Timeout { get; init; } = TimeSpan.FromSeconds(30);
+
+    /// <summary>
+    /// The http headers sent with the request.
+    /// </summary>
+    internal Headers Headers { get; init; } = new();
 }
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/RequestOptions.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Public/RequestOptions.cs
similarity index 74%
rename from seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/RequestOptions.cs
rename to seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Public/RequestOptions.cs
index c5907ea7c40..4d4bc1763d6 100644
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/RequestOptions.cs
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Public/RequestOptions.cs
@@ -1,9 +1,10 @@
 using System;
 using System.Net.Http;
+using SeedServerSentEvents.Core;
 
 #nullable enable
 
-namespace SeedServerSentEvents.Core;
+namespace SeedServerSentEvents;
 
 public partial class RequestOptions
 {
@@ -26,4 +27,9 @@ public partial class RequestOptions
     /// The timeout for the request.
     /// </summary>
     public TimeSpan? Timeout { get; init; }
+
+    /// <summary>
+    /// The http headers sent with the request.
+    /// </summary>
+    internal Headers Headers { get; init; } = new();
 }
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/SeedServerSentEventsApiException.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Public/SeedServerSentEventsApiException.cs
similarity index 66%
rename from seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/SeedServerSentEventsApiException.cs
rename to seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Public/SeedServerSentEventsApiException.cs
index 54884e37904..3279f8f7911 100644
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/SeedServerSentEventsApiException.cs
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Public/SeedServerSentEventsApiException.cs
@@ -1,8 +1,4 @@
-using SeedServerSentEvents.Core;
-
-#nullable enable
-
-namespace SeedServerSentEvents.Core;
+namespace SeedServerSentEvents;
 
 /// <summary>
 /// This exception type will be thrown for any non-2XX API responses.
@@ -19,9 +15,4 @@ public class SeedServerSentEventsApiException(string message, int statusCode, ob
     /// The body of the response that triggered the exception.
     /// </summary>
     public object Body => body;
-
-    public override string ToString()
-    {
-        return $"SeedServerSentEventsApiException {{ message: {Message}, statusCode: {StatusCode}, body: {Body} }}";
-    }
 }
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/SeedServerSentEventsException.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Public/SeedServerSentEventsException.cs
similarity index 87%
rename from seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/SeedServerSentEventsException.cs
rename to seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Public/SeedServerSentEventsException.cs
index 0b4fe99d37a..63d07005ada 100644
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/SeedServerSentEventsException.cs
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Public/SeedServerSentEventsException.cs
@@ -2,7 +2,7 @@
 
 #nullable enable
 
-namespace SeedServerSentEvents.Core;
+namespace SeedServerSentEvents;
 
 /// <summary>
 /// Base exception class for all exceptions thrown by the SDK.
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Public/Version.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Public/Version.cs
new file mode 100644
index 00000000000..8296b59ade5
--- /dev/null
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/Public/Version.cs
@@ -0,0 +1,6 @@
+namespace SeedServerSentEvents;
+
+internal class Version
+{
+    public const string Current = "0.0.1";
+}
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/RawClient.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/RawClient.cs
index 2c8bcc1a1cb..cbb8c0c992b 100644
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/RawClient.cs
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/RawClient.cs
@@ -1,5 +1,6 @@
 using System.Net.Http;
 using System.Text;
+using System.Threading;
 
 namespace SeedServerSentEvents.Core;
 
@@ -8,65 +9,28 @@ namespace SeedServerSentEvents.Core;
 /// <summary>
 /// Utility class for making raw HTTP requests to the API.
 /// </summary>
-public class RawClient(
-    Dictionary<string, string> headers,
-    Dictionary<string, Func<string>> headerSuppliers,
-    ClientOptions clientOptions
-)
+internal class RawClient(ClientOptions clientOptions)
 {
-    /// <summary>
-    /// The http client used to make requests.
-    /// </summary>
-    public readonly ClientOptions Options = clientOptions;
+    private const int InitialRetryDelayMs = 1000;
+    private const int MaxRetryDelayMs = 60000;
 
     /// <summary>
-    /// Global headers to be sent with every request.
+    /// The client options applied on every request.
     /// </summary>
-    private readonly Dictionary<string, string> _headers = headers;
+    public readonly ClientOptions Options = clientOptions;
 
-    public async Task<ApiResponse> MakeRequestAsync(BaseApiRequest request)
+    public async Task<ApiResponse> MakeRequestAsync(
+        BaseApiRequest request,
+        CancellationToken cancellationToken = default
+    )
     {
-        var url = BuildUrl(request);
-        var httpRequest = new HttpRequestMessage(request.Method, url);
-        if (request.ContentType != null)
-        {
-            request.Headers.Add("Content-Type", request.ContentType);
-        }
-        // Add global headers to the request
-        foreach (var header in _headers)
-        {
-            httpRequest.Headers.Add(header.Key, header.Value);
-        }
-        // Add global headers to the request from supplier
-        foreach (var header in headerSuppliers)
-        {
-            httpRequest.Headers.Add(header.Key, header.Value.Invoke());
-        }
-        // Add request headers to the request
-        foreach (var header in request.Headers)
-        {
-            httpRequest.Headers.Add(header.Key, header.Value);
-        }
-        // Add the request body to the request
-        if (request is JsonApiRequest jsonRequest)
-        {
-            if (jsonRequest.Body != null)
-            {
-                httpRequest.Content = new StringContent(
-                    JsonUtils.Serialize(jsonRequest.Body),
-                    Encoding.UTF8,
-                    "application/json"
-                );
-            }
-        }
-        else if (request is StreamApiRequest { Body: not null } streamRequest)
-        {
-            httpRequest.Content = new StreamContent(streamRequest.Body);
-        }
-        // Send the request
-        var httpClient = request.Options?.HttpClient ?? Options.HttpClient;
-        var response = await httpClient.SendAsync(httpRequest);
-        return new ApiResponse { StatusCode = (int)response.StatusCode, Raw = response };
+        // Apply the request timeout.
+        var cts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
+        var timeout = request.Options?.Timeout ?? Options.Timeout;
+        cts.CancelAfter(timeout);
+
+        // Send the request.
+        return await SendWithRetriesAsync(request, cts.Token);
     }
 
     public record BaseApiRequest
@@ -81,7 +45,7 @@ public record BaseApiRequest
 
         public Dictionary<string, object> Query { get; init; } = new();
 
-        public Dictionary<string, string> Headers { get; init; } = new();
+        public Headers Headers { get; init; } = new();
 
         public RequestOptions? Options { get; init; }
     }
@@ -112,7 +76,67 @@ public record ApiResponse
         public required HttpResponseMessage Raw { get; init; }
     }
 
-    private string BuildUrl(BaseApiRequest request)
+    private async Task<ApiResponse> SendWithRetriesAsync(
+        BaseApiRequest request,
+        CancellationToken cancellationToken
+    )
+    {
+        var httpClient = request.Options?.HttpClient ?? Options.HttpClient;
+        var maxRetries = request.Options?.MaxRetries ?? Options.MaxRetries;
+        var response = await httpClient.SendAsync(BuildHttpRequest(request), cancellationToken);
+        for (var i = 0; i < maxRetries; i++)
+        {
+            if (!ShouldRetry(response))
+            {
+                break;
+            }
+            var delayMs = Math.Min(InitialRetryDelayMs * (int)Math.Pow(2, i), MaxRetryDelayMs);
+            await System.Threading.Tasks.Task.Delay(delayMs, cancellationToken);
+            response = await httpClient.SendAsync(BuildHttpRequest(request), cancellationToken);
+        }
+        return new ApiResponse { StatusCode = (int)response.StatusCode, Raw = response };
+    }
+
+    private static bool ShouldRetry(HttpResponseMessage response)
+    {
+        var statusCode = (int)response.StatusCode;
+        return statusCode is 408 or 429 or >= 500;
+    }
+
+    private HttpRequestMessage BuildHttpRequest(BaseApiRequest request)
+    {
+        var url = BuildUrl(request);
+        var httpRequest = new HttpRequestMessage(request.Method, url);
+        switch (request)
+        {
+            // Add the request body to the request.
+            case JsonApiRequest jsonRequest:
+            {
+                if (jsonRequest.Body != null)
+                {
+                    httpRequest.Content = new StringContent(
+                        JsonUtils.Serialize(jsonRequest.Body),
+                        Encoding.UTF8,
+                        "application/json"
+                    );
+                }
+                break;
+            }
+            case StreamApiRequest { Body: not null } streamRequest:
+                httpRequest.Content = new StreamContent(streamRequest.Body);
+                break;
+        }
+        if (request.ContentType != null)
+        {
+            request.Headers.Add("Content-Type", request.ContentType);
+        }
+        SetHeaders(httpRequest, Options.Headers);
+        SetHeaders(httpRequest, request.Headers);
+        SetHeaders(httpRequest, request.Options?.Headers ?? new Headers());
+        return httpRequest;
+    }
+
+    private static string BuildUrl(BaseApiRequest request)
     {
         var baseUrl = request.Options?.BaseUrl ?? request.BaseUrl;
         var trimmedBaseUrl = baseUrl.TrimEnd('/');
@@ -143,7 +167,19 @@ private string BuildUrl(BaseApiRequest request)
                 return current;
             }
         );
-        url = url.Substring(0, url.Length - 1);
+        url = url[..^1];
         return url;
     }
+
+    private static void SetHeaders(HttpRequestMessage httpRequest, Headers headers)
+    {
+        foreach (var header in headers)
+        {
+            var value = header.Value?.Match(str => str, func => func.Invoke());
+            if (value != null)
+            {
+                httpRequest.Headers.TryAddWithoutValidation(header.Key, value);
+            }
+        }
+    }
 }
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/StringEnumSerializer.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/StringEnumSerializer.cs
index 143654892f7..707a72f31b4 100644
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/StringEnumSerializer.cs
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/Core/StringEnumSerializer.cs
@@ -4,7 +4,7 @@
 
 namespace SeedServerSentEvents.Core;
 
-public class StringEnumSerializer<TEnum> : JsonConverter<TEnum>
+internal class StringEnumSerializer<TEnum> : JsonConverter<TEnum>
     where TEnum : struct, System.Enum
 {
     private readonly Dictionary<TEnum, string> _enumToString = new();
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/SeedServerSentEvents.csproj b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/SeedServerSentEvents.csproj
index 11f735b98cc..dfaed0b7562 100644
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/SeedServerSentEvents.csproj
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/SeedServerSentEvents.csproj
@@ -11,7 +11,7 @@
         <PackageReadmeFile>README.md</PackageReadmeFile>
         <PackageProjectUrl>https://github.com/server-sent-events/fern</PackageProjectUrl>
     </PropertyGroup>
-    
+
     <PropertyGroup Condition="'$(TargetFramework)' == 'net6.0' Or '$(TargetFramework)' == 'net462' Or '$(TargetFramework)' == 'netstandard2.0'">
         <PolySharpIncludeRuntimeSupportedAttributes>true</PolySharpIncludeRuntimeSupportedAttributes>
     </PropertyGroup>
@@ -41,5 +41,10 @@
         <None Include="..\..\README.md" Pack="true" PackagePath=""/>
     </ItemGroup>
 
+    <ItemGroup>
+        <AssemblyAttribute Include="System.Runtime.CompilerServices.InternalsVisibleTo">
+            <_Parameter1>SeedServerSentEvents.Test</_Parameter1>
+        </AssemblyAttribute>
+    </ItemGroup>
 
 </Project>
diff --git a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/SeedServerSentEventsClient.cs b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/SeedServerSentEventsClient.cs
index e91de74227f..09c8e604565 100644
--- a/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/SeedServerSentEventsClient.cs
+++ b/seed/csharp-sdk/server-sent-events/src/SeedServerSentEvents/SeedServerSentEventsClient.cs
@@ -1,5 +1,3 @@
-using System;
-using SeedServerSentEvents;
 using SeedServerSentEvents.Core;
 
 #nullable enable
@@ -12,11 +10,24 @@ public partial class SeedServerSentEventsClient
 
     public SeedServerSentEventsClient(ClientOptions? clientOptions = null)
     {
-        _client = new RawClient(
-            new Dictionary<string, string>() { { "X-Fern-Language", "C#" }, },
-            new Dictionary<string, Func<string>>() { },
-            clientOptions ?? new ClientOptions()
+        var defaultHeaders = new Headers(
+            new Dictionary<string, string>()
+            {
+                { "X-Fern-Language", "C#" },
+                { "X-Fern-SDK-Name", "SeedServerSentEvents" },
+                { "X-Fern-SDK-Version", Version.Current },
+                { "User-Agent", "Fernserver-sent-events/0.0.1" },
+            }
         );
+        clientOptions ??= new ClientOptions();
+        foreach (var header in defaultHeaders)
+        {
+            if (!clientOptions.Headers.ContainsKey(header.Key))
+            {
+                clientOptions.Headers[header.Key] = header.Value;
+            }
+        }
+        _client = new RawClient(clientOptions);
         Completions = new CompletionsClient(_client);
     }
 
diff --git a/seed/java-model/server-sent-events/src/main/java/com/seed/serverSentEvents/model/completions/StreamedCompletion.java b/seed/java-model/server-sent-events/src/main/java/com/seed/serverSentEvents/model/completions/StreamedCompletion.java
index 0a05329a4a7..b271add6f6f 100644
--- a/seed/java-model/server-sent-events/src/main/java/com/seed/serverSentEvents/model/completions/StreamedCompletion.java
+++ b/seed/java-model/server-sent-events/src/main/java/com/seed/serverSentEvents/model/completions/StreamedCompletion.java
@@ -91,7 +91,7 @@ public Builder from(StreamedCompletion other) {
         @java.lang.Override
         @JsonSetter("delta")
         public _FinalStage delta(String delta) {
-            this.delta = delta;
+            this.delta = Objects.requireNonNull(delta, "delta must not be null");
             return this;
         }
 
diff --git a/seed/java-sdk/server-sent-events/snippet-templates.json b/seed/java-sdk/server-sent-events/snippet-templates.json
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/seed/java-sdk/server-sent-events/snippet.json b/seed/java-sdk/server-sent-events/snippet.json
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/seed/java-sdk/server-sent-events/src/main/java/com/seed/serverSentEvents/core/FileStream.java b/seed/java-sdk/server-sent-events/src/main/java/com/seed/serverSentEvents/core/FileStream.java
new file mode 100644
index 00000000000..cf1177b976d
--- /dev/null
+++ b/seed/java-sdk/server-sent-events/src/main/java/com/seed/serverSentEvents/core/FileStream.java
@@ -0,0 +1,60 @@
+/**
+ * This file was auto-generated by Fern from our API Definition.
+ */
+package com.seed.serverSentEvents.core;
+
+import java.io.InputStream;
+import java.util.Objects;
+import okhttp3.MediaType;
+import okhttp3.RequestBody;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * Represents a file stream with associated metadata for file uploads.
+ */
+public class FileStream {
+    private final InputStream inputStream;
+    private final String fileName;
+    private final MediaType contentType;
+
+    /**
+     * Constructs a FileStream with the given input stream and optional metadata.
+     *
+     * @param inputStream The input stream of the file content. Must not be null.
+     * @param fileName The name of the file, or null if unknown.
+     * @param contentType The MIME type of the file content, or null if unknown.
+     * @throws NullPointerException if inputStream is null
+     */
+    public FileStream(InputStream inputStream, @Nullable String fileName, @Nullable MediaType contentType) {
+        this.inputStream = Objects.requireNonNull(inputStream, "Input stream cannot be null");
+        this.fileName = fileName;
+        this.contentType = contentType;
+    }
+
+    public FileStream(InputStream inputStream) {
+        this(inputStream, null, null);
+    }
+
+    public InputStream getInputStream() {
+        return inputStream;
+    }
+
+    @Nullable
+    public String getFileName() {
+        return fileName;
+    }
+
+    @Nullable
+    public MediaType getContentType() {
+        return contentType;
+    }
+
+    /**
+     * Creates a RequestBody suitable for use with OkHttp client.
+     *
+     * @return A RequestBody instance representing this file stream.
+     */
+    public RequestBody toRequestBody() {
+        return new InputStreamRequestBody(contentType, inputStream);
+    }
+}
diff --git a/seed/java-sdk/server-sent-events/src/main/java/com/seed/serverSentEvents/core/InputStreamRequestBody.java b/seed/java-sdk/server-sent-events/src/main/java/com/seed/serverSentEvents/core/InputStreamRequestBody.java
new file mode 100644
index 00000000000..a97c3290df6
--- /dev/null
+++ b/seed/java-sdk/server-sent-events/src/main/java/com/seed/serverSentEvents/core/InputStreamRequestBody.java
@@ -0,0 +1,79 @@
+/**
+ * This file was auto-generated by Fern from our API Definition.
+ */
+package com.seed.serverSentEvents.core;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Objects;
+import okhttp3.MediaType;
+import okhttp3.RequestBody;
+import okhttp3.internal.Util;
+import okio.BufferedSink;
+import okio.Okio;
+import okio.Source;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * A custom implementation of OkHttp's RequestBody that wraps an InputStream.
+ * This class allows streaming of data from an InputStream directly to an HTTP request body,
+ * which is useful for file uploads or sending large amounts of data without loading it all into memory.
+ */
+public class InputStreamRequestBody extends RequestBody {
+    private final InputStream inputStream;
+    private final MediaType contentType;
+
+    /**
+     * Constructs an InputStreamRequestBody with the specified content type and input stream.
+     *
+     * @param contentType the MediaType of the content, or null if not known
+     * @param inputStream the InputStream containing the data to be sent
+     * @throws NullPointerException if inputStream is null
+     */
+    public InputStreamRequestBody(@Nullable MediaType contentType, InputStream inputStream) {
+        this.contentType = contentType;
+        this.inputStream = Objects.requireNonNull(inputStream, "inputStream == null");
+    }
+
+    /**
+     * Returns the content type of this request body.
+     *
+     * @return the MediaType of the content, or null if not specified
+     */
+    @Nullable
+    @Override
+    public MediaType contentType() {
+        return contentType;
+    }
+
+    /**
+     * Returns the content length of this request body, if known.
+     * This method attempts to determine the length using the InputStream's available() method,
+     * which may not always accurately reflect the total length of the stream.
+     *
+     * @return the content length, or -1 if the length is unknown
+     * @throws IOException if an I/O error occurs
+     */
+    @Override
+    public long contentLength() throws IOException {
+        return inputStream.available() == 0 ? -1 : inputStream.available();
+    }
+
+    /**
+     * Writes the content of the InputStream to the given BufferedSink.
+     * This method is responsible for transferring the data from the InputStream to the network request.
+     *
+     * @param sink the BufferedSink to write the content to
+     * @throws IOException if an I/O error occurs during writing
+     */
+    @Override
+    public void writeTo(BufferedSink sink) throws IOException {
+        Source source = null;
+        try {
+            source = Okio.source(inputStream);
+            sink.writeAll(source);
+        } finally {
+            Util.closeQuietly(Objects.requireNonNull(source));
+        }
+    }
+}
diff --git a/seed/java-sdk/server-sent-events/src/main/java/com/seed/serverSentEvents/resources/completions/requests/StreamCompletionRequest.java b/seed/java-sdk/server-sent-events/src/main/java/com/seed/serverSentEvents/resources/completions/requests/StreamCompletionRequest.java
index d05a1da4881..a27c8e22024 100644
--- a/seed/java-sdk/server-sent-events/src/main/java/com/seed/serverSentEvents/resources/completions/requests/StreamCompletionRequest.java
+++ b/seed/java-sdk/server-sent-events/src/main/java/com/seed/serverSentEvents/resources/completions/requests/StreamCompletionRequest.java
@@ -14,6 +14,7 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Objects;
+import org.jetbrains.annotations.NotNull;
 
 @JsonInclude(JsonInclude.Include.NON_ABSENT)
 @JsonDeserialize(builder = StreamCompletionRequest.Builder.class)
@@ -62,7 +63,7 @@ public static QueryStage builder() {
     }
 
     public interface QueryStage {
-        _FinalStage query(String query);
+        _FinalStage query(@NotNull String query);
 
         Builder from(StreamCompletionRequest other);
     }
@@ -88,8 +89,8 @@ public Builder from(StreamCompletionRequest other) {
 
         @java.lang.Override
         @JsonSetter("query")
-        public _FinalStage query(String query) {
-            this.query = query;
+        public _FinalStage query(@NotNull String query) {
+            this.query = Objects.requireNonNull(query, "query must not be null");
             return this;
         }
 
diff --git a/seed/java-sdk/server-sent-events/src/main/java/com/seed/serverSentEvents/resources/completions/types/StreamedCompletion.java b/seed/java-sdk/server-sent-events/src/main/java/com/seed/serverSentEvents/resources/completions/types/StreamedCompletion.java
index 11e6253dcad..cf21a4b65e4 100644
--- a/seed/java-sdk/server-sent-events/src/main/java/com/seed/serverSentEvents/resources/completions/types/StreamedCompletion.java
+++ b/seed/java-sdk/server-sent-events/src/main/java/com/seed/serverSentEvents/resources/completions/types/StreamedCompletion.java
@@ -16,6 +16,7 @@
 import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
+import org.jetbrains.annotations.NotNull;
 
 @JsonInclude(JsonInclude.Include.NON_ABSENT)
 @JsonDeserialize(builder = StreamedCompletion.Builder.class)
@@ -72,7 +73,7 @@ public static DeltaStage builder() {
     }
 
     public interface DeltaStage {
-        _FinalStage delta(String delta);
+        _FinalStage delta(@NotNull String delta);
 
         Builder from(StreamedCompletion other);
     }
@@ -105,8 +106,8 @@ public Builder from(StreamedCompletion other) {
 
         @java.lang.Override
         @JsonSetter("delta")
-        public _FinalStage delta(String delta) {
-            this.delta = delta;
+        public _FinalStage delta(@NotNull String delta) {
+            this.delta = Objects.requireNonNull(delta, "delta must not be null");
             return this;
         }
 
diff --git a/seed/php-model/server-sent-events/.github/workflows/ci.yml b/seed/php-model/server-sent-events/.github/workflows/ci.yml
new file mode 100644
index 00000000000..258bf33a19f
--- /dev/null
+++ b/seed/php-model/server-sent-events/.github/workflows/ci.yml
@@ -0,0 +1,48 @@
+name: ci
+
+on: [push]
+
+jobs:
+  compile:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: "8.1"
+
+      - name: Install tools
+        run: |
+          composer install
+
+      - name: Build
+        run: |
+          composer build
+
+      - name: Analyze
+        run: |
+          composer analyze
+
+  unit-tests:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: "8.1"
+
+      - name: Install tools
+        run: |
+          composer install
+
+      - name: Run Tests
+        run: |
+          composer test
\ No newline at end of file
diff --git a/seed/php-model/server-sent-events/.gitignore b/seed/php-model/server-sent-events/.gitignore
new file mode 100644
index 00000000000..f38efc46ade
--- /dev/null
+++ b/seed/php-model/server-sent-events/.gitignore
@@ -0,0 +1,4 @@
+.php-cs-fixer.cache
+.phpunit.result.cache
+composer.lock
+vendor/
\ No newline at end of file
diff --git a/seed/php-model/server-sent-events/.mock/definition/api.yml b/seed/php-model/server-sent-events/.mock/definition/api.yml
new file mode 100644
index 00000000000..80e84c41785
--- /dev/null
+++ b/seed/php-model/server-sent-events/.mock/definition/api.yml
@@ -0,0 +1 @@
+name: server-sent-events
diff --git a/seed/php-model/server-sent-events/.mock/definition/completions.yml b/seed/php-model/server-sent-events/.mock/definition/completions.yml
new file mode 100644
index 00000000000..d1748fad19e
--- /dev/null
+++ b/seed/php-model/server-sent-events/.mock/definition/completions.yml
@@ -0,0 +1,22 @@
+types:
+  StreamedCompletion:
+    properties:
+      delta: string
+      tokens: optional<integer>
+
+service:
+  auth: false
+  base-path: ""
+  endpoints:
+    stream:
+      method: POST
+      path: /stream
+      request:
+        name: StreamCompletionRequest
+        body:
+          properties:
+            query: string
+      response-stream:
+        type: StreamedCompletion
+        format: sse
+        terminator: "[[DONE]]"
diff --git a/seed/php-model/server-sent-events/.mock/fern.config.json b/seed/php-model/server-sent-events/.mock/fern.config.json
new file mode 100644
index 00000000000..4c8e54ac313
--- /dev/null
+++ b/seed/php-model/server-sent-events/.mock/fern.config.json
@@ -0,0 +1 @@
+{"organization": "fern-test", "version": "*"}
\ No newline at end of file
diff --git a/seed/php-model/server-sent-events/.mock/generators.yml b/seed/php-model/server-sent-events/.mock/generators.yml
new file mode 100644
index 00000000000..0967ef424bc
--- /dev/null
+++ b/seed/php-model/server-sent-events/.mock/generators.yml
@@ -0,0 +1 @@
+{}
diff --git a/seed/php-model/server-sent-events/composer.json b/seed/php-model/server-sent-events/composer.json
new file mode 100644
index 00000000000..7f5821806d4
--- /dev/null
+++ b/seed/php-model/server-sent-events/composer.json
@@ -0,0 +1,40 @@
+
+{
+  "name": "seed/seed",
+  "version": "0.0.1",
+  "description": "Seed PHP Library",
+  "keywords": [
+    "seed",
+    "api",
+    "sdk"
+  ],
+  "license": [],
+  "require": {
+    "php": "^8.1",
+    "ext-json": "*",
+    "guzzlehttp/guzzle": "^7.9"
+  },
+  "require-dev": {
+    "phpunit/phpunit": "^9.0",
+    "friendsofphp/php-cs-fixer": "3.5.0",
+    "phpstan/phpstan": "^1.12"
+  },
+  "autoload": {
+    "psr-4": {
+      "Seed\\": "src/"
+    }
+  },
+  "autoload-dev": {
+    "psr-4": {
+      "\\Seed\\Tests\\": "tests/"
+    }
+  },
+  "scripts": {
+    "build": [
+      "@php -l src",
+      "@php -l tests"
+    ],
+    "test": "phpunit",
+    "analyze": "phpstan analyze src"
+  }
+}
diff --git a/seed/php-model/server-sent-events/phpstan.neon b/seed/php-model/server-sent-events/phpstan.neon
new file mode 100644
index 00000000000..29a11a92a19
--- /dev/null
+++ b/seed/php-model/server-sent-events/phpstan.neon
@@ -0,0 +1,5 @@
+parameters:
+    level: max
+    paths:
+        - src
+        - tests
\ No newline at end of file
diff --git a/seed/php-model/server-sent-events/phpunit.xml b/seed/php-model/server-sent-events/phpunit.xml
new file mode 100644
index 00000000000..54630a51163
--- /dev/null
+++ b/seed/php-model/server-sent-events/phpunit.xml
@@ -0,0 +1,7 @@
+<phpunit bootstrap="vendor/autoload.php">
+    <testsuites>
+        <testsuite name="Test Suite">
+            <directory suffix="Test.php">tests</directory>
+        </testsuite>
+    </testsuites>
+</phpunit>
\ No newline at end of file
diff --git a/seed/php-model/server-sent-events/snippet-templates.json b/seed/php-model/server-sent-events/snippet-templates.json
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/seed/php-model/server-sent-events/snippet.json b/seed/php-model/server-sent-events/snippet.json
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/seed/php-model/server-sent-events/src/Completions/StreamedCompletion.php b/seed/php-model/server-sent-events/src/Completions/StreamedCompletion.php
new file mode 100644
index 00000000000..59208a9fc57
--- /dev/null
+++ b/seed/php-model/server-sent-events/src/Completions/StreamedCompletion.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace Seed\Completions;
+
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+
+class StreamedCompletion extends SerializableType
+{
+    /**
+     * @var string $delta
+     */
+    #[JsonProperty('delta')]
+    public string $delta;
+
+    /**
+     * @var ?int $tokens
+     */
+    #[JsonProperty('tokens')]
+    public ?int $tokens;
+
+    /**
+     * @param array{
+     *   delta: string,
+     *   tokens?: ?int,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->delta = $values['delta'];
+        $this->tokens = $values['tokens'] ?? null;
+    }
+}
diff --git a/seed/php-model/server-sent-events/src/Core/ArrayType.php b/seed/php-model/server-sent-events/src/Core/ArrayType.php
new file mode 100644
index 00000000000..b2ed8bf12b2
--- /dev/null
+++ b/seed/php-model/server-sent-events/src/Core/ArrayType.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Seed\Core;
+
+use Attribute;
+
+#[Attribute(Attribute::TARGET_PROPERTY)]
+class ArrayType
+{
+    /**
+     * @param mixed[] $type Array in the form ['keyType' => 'valueType'] for maps, or ['valueType'] for lists
+     */
+    public function __construct(public array $type)
+    {
+    }
+}
diff --git a/seed/php-model/server-sent-events/src/Core/Constant.php b/seed/php-model/server-sent-events/src/Core/Constant.php
new file mode 100644
index 00000000000..abbac7f6649
--- /dev/null
+++ b/seed/php-model/server-sent-events/src/Core/Constant.php
@@ -0,0 +1,12 @@
+<?php
+
+namespace Seed\Core;
+
+use DateTimeInterface;
+
+class Constant
+{
+    public const DateFormat = 'Y-m-d';
+    public const DateDeserializationFormat = "!" . self::DateFormat;
+    public const DateTimeFormat = DateTimeInterface::RFC3339;
+}
diff --git a/seed/php-model/server-sent-events/src/Core/DateType.php b/seed/php-model/server-sent-events/src/Core/DateType.php
new file mode 100644
index 00000000000..dcf05bb2710
--- /dev/null
+++ b/seed/php-model/server-sent-events/src/Core/DateType.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Seed\Core;
+
+use Attribute;
+
+#[Attribute(Attribute::TARGET_PROPERTY)]
+class DateType
+{
+    public const TYPE_DATE = 'date';
+    public const TYPE_DATETIME = 'datetime';
+
+    public function __construct(public string $type)
+    {
+    }
+}
diff --git a/seed/php-model/server-sent-events/src/Core/JsonDecoder.php b/seed/php-model/server-sent-events/src/Core/JsonDecoder.php
new file mode 100644
index 00000000000..34651d0b9eb
--- /dev/null
+++ b/seed/php-model/server-sent-events/src/Core/JsonDecoder.php
@@ -0,0 +1,147 @@
+<?php
+
+namespace Seed\Core;
+
+use DateTime;
+use Exception;
+use JsonException;
+
+class JsonDecoder
+{
+    /**
+     * Decodes a JSON string and returns a string.
+     *
+     * @param string $json The JSON string to decode.
+     * @return string The decoded string.
+     * @throws JsonException If the decoded value is not a string.
+     */
+    public static function decodeString(string $json): string
+    {
+        $decoded = self::decode($json);
+        if (!is_string($decoded)) {
+            throw new JsonException("Unexpected non-string json value: " . $json);
+        }
+        return $decoded;
+    }
+
+    /**
+     * Decodes a JSON string and returns a boolean.
+     *
+     * @param string $json The JSON string to decode.
+     * @return bool The decoded boolean.
+     * @throws JsonException If the decoded value is not a boolean.
+     */
+    public static function decodeBool(string $json): bool
+    {
+        $decoded = self::decode($json);
+        if (!is_bool($decoded)) {
+            throw new JsonException("Unexpected non-boolean json value: " . $json);
+        }
+        return $decoded;
+    }
+
+    /**
+     * Decodes a JSON string and returns a DateTime object.
+     *
+     * @param string $json The JSON string to decode.
+     * @return DateTime The decoded DateTime object.
+     * @throws JsonException If the decoded value is not a valid datetime string.
+     */
+    public static function decodeDateTime(string $json): DateTime
+    {
+        $decoded = self::decode($json);
+        if (!is_string($decoded)) {
+            throw new JsonException("Unexpected non-string json value for datetime: " . $json);
+        }
+        return JsonDeserializer::deserializeDateTime($decoded);
+    }
+
+    /**
+     * Decodes a JSON string and returns a DateTime object representing a date.
+     *
+     * @param string $json The JSON string to decode.
+     * @return DateTime The decoded DateTime object.
+     * @throws JsonException If the decoded value is not a valid date string.
+     */
+    public static function decodeDate(string $json): DateTime
+    {
+        $decoded = self::decode($json);
+        if (!is_string($decoded)) {
+            throw new JsonException("Unexpected non-string json value for date: " . $json);
+        }
+        return JsonDeserializer::deserializeDate($decoded);
+    }
+
+    /**
+     * Decodes a JSON string and returns a float.
+     *
+     * @param string $json The JSON string to decode.
+     * @return float The decoded float.
+     * @throws JsonException If the decoded value is not a float.
+     */
+    public static function decodeFloat(string $json): float
+    {
+        $decoded = self::decode($json);
+        if (!is_float($decoded)) {
+            throw new JsonException("Unexpected non-float json value: " . $json);
+        }
+        return $decoded;
+    }
+
+    /**
+     * Decodes a JSON string and returns an integer.
+     *
+     * @param string $json The JSON string to decode.
+     * @return int The decoded integer.
+     * @throws JsonException If the decoded value is not an integer.
+     */
+    public static function decodeInt(string $json): int
+    {
+        $decoded = self::decode($json);
+        if (!is_int($decoded)) {
+            throw new JsonException("Unexpected non-integer json value: " . $json);
+        }
+        return $decoded;
+    }
+
+    /**
+     * Decodes a JSON string into an array and deserializes it based on the provided type.
+     *
+     * @param string $json The JSON string to decode.
+     * @param mixed[]|array<string, mixed> $type The type definition for deserialization.
+     * @return mixed[]|array<string, mixed> The deserialized array.
+     * @throws JsonException If the decoded value is not an array.
+     */
+    public static function decodeArray(string $json, array $type): array
+    {
+        $decoded = self::decode($json);
+        if (!is_array($decoded)) {
+            throw new JsonException("Unexpected non-array json value: " . $json);
+        }
+        return JsonDeserializer::deserializeArray($decoded, $type);
+    }
+
+    /**
+     * Decodes a JSON string and returns a mixed.
+     *
+     * @param string $json The JSON string to decode.
+     * @return mixed The decoded mixed.
+     * @throws JsonException If the decoded value is not an mixed.
+     */
+    public static function decodeMixed(string $json): mixed
+    {
+        return self::decode($json);
+    }
+
+    /**
+     * Decodes a JSON string into a PHP value.
+     *
+     * @param string $json The JSON string to decode.
+     * @return mixed The decoded value.
+     * @throws JsonException If an error occurs during JSON decoding.
+     */
+    public static function decode(string $json): mixed
+    {
+        return json_decode($json, associative: true, flags: JSON_THROW_ON_ERROR);
+    }
+}
diff --git a/seed/php-model/server-sent-events/src/Core/JsonDeserializer.php b/seed/php-model/server-sent-events/src/Core/JsonDeserializer.php
new file mode 100644
index 00000000000..4c9998886ee
--- /dev/null
+++ b/seed/php-model/server-sent-events/src/Core/JsonDeserializer.php
@@ -0,0 +1,187 @@
+<?php
+
+namespace Seed\Core;
+
+use DateTime;
+use Exception;
+use JsonException;
+
+class JsonDeserializer
+{
+    /**
+     * Deserializes a string into a DateTime object.
+     *
+     * @param string $datetime The date/time string to deserialize.
+     * @return DateTime
+     * @throws JsonException If the DateTime creation fails.
+     */
+    public static function deserializeDateTime(string $datetime): DateTime
+    {
+        try {
+            return new DateTime($datetime);
+        } catch (Exception $e) {
+            throw new JsonException("Failed to create DateTime from string: $datetime", previous: $e);
+        }
+    }
+
+    /**
+     * Deserializes a string into a DateTime object using a specific format.
+     *
+     * @param string $date The date string to deserialize.
+     * @return DateTime
+     * @throws JsonException If the date creation fails.
+     */
+    public static function deserializeDate(string $date): DateTime
+    {
+        $dateTime = DateTime::createFromFormat(Constant::DateDeserializationFormat, $date);
+        if ($dateTime === false) {
+            throw new JsonException("Failed to create date from string: $date");
+        }
+        return $dateTime;
+    }
+
+    /**
+     * Deserializes an array based on type annotations (either a list or a map).
+     *
+     * @param mixed[]|array<string, mixed> $data The array to be deserialized.
+     * @param mixed[]|array<string, mixed> $type The type definition from the annotation.
+     * @return mixed[]|array<string, mixed> The deserialized array.
+     * @throws JsonException If deserialization fails.
+     */
+    public static function deserializeArray(array $data, array $type): array
+    {
+        return Utils::isMapType($type)
+            ? self::deserializeMap($data, $type)
+            : self::deserializeList($data, $type);
+    }
+
+    /**
+     * Deserializes a value based on its type definition.
+     *
+     * @param mixed $data The data to deserialize.
+     * @param mixed $type The type definition.
+     * @return mixed The deserialized value.
+     * @throws JsonException If deserialization fails.
+     */
+    private static function deserializeValue(mixed $data, mixed $type): mixed
+    {
+        if ($type instanceof Union) {
+            foreach ($type->types as $unionType) {
+                try {
+                    return self::deserializeSingleValue($data, $unionType);
+                } catch (Exception) {
+                    continue;
+                }
+            }
+            $readableType = Utils::getReadableType($data);
+            throw new JsonException(
+                "Cannot deserialize value of type $readableType with any of the union types: " . $type
+            );
+        }
+        if (is_array($type)) {
+            return self::deserializeArray((array)$data, $type);
+        }
+
+        if (gettype($type) != "string") {
+            throw new JsonException("Unexpected non-string type.");
+        }
+        return self::deserializeSingleValue($data, $type);
+    }
+
+    /**
+     * Deserializes a single value based on its expected type.
+     *
+     * @param mixed $data The data to deserialize.
+     * @param string $type The expected type.
+     * @return mixed The deserialized value.
+     * @throws JsonException If deserialization fails.
+     */
+    private static function deserializeSingleValue(mixed $data, string $type): mixed
+    {
+        if ($type === 'null' && $data === null) {
+            return null;
+        }
+
+        if ($type === 'date' && is_string($data)) {
+            return self::deserializeDate($data);
+        }
+
+        if ($type === 'datetime' && is_string($data)) {
+            return self::deserializeDateTime($data);
+        }
+
+        if ($type === 'mixed') {
+            return $data;
+        }
+
+        if (class_exists($type) && is_array($data)) {
+            return self::deserializeObject($data, $type);
+        }
+
+        // Handle floats as a special case since gettype($data) returns "double" for float values in PHP, and because
+        // floats make come through from json_decoded as integers
+        if ($type === 'float' && (is_numeric($data))) {
+            return (float) $data;
+        }
+
+        if (gettype($data) === $type) {
+            return $data;
+        }
+
+        throw new JsonException("Unable to deserialize value of type '" . gettype($data) . "' as '$type'.");
+    }
+
+    /**
+     * Deserializes an array into an object of the given type.
+     *
+     * @param array<string, mixed> $data The data to deserialize.
+     * @param string $type The class name of the object to deserialize into.
+     *
+     * @return object The deserialized object.
+     *
+     * @throws JsonException If the type does not implement SerializableType.
+     */
+    public static function deserializeObject(array $data, string $type): object
+    {
+        if (!is_subclass_of($type, SerializableType::class)) {
+            throw new JsonException("$type is not a subclass of SerializableType.");
+        }
+        return $type::jsonDeserialize($data);
+    }
+
+    /**
+     * Deserializes a map (associative array) with defined key and value types.
+     *
+     * @param array<string, mixed> $data The associative array to deserialize.
+     * @param array<string, mixed> $type The type definition for the map.
+     * @return array<string, mixed> The deserialized map.
+     * @throws JsonException If deserialization fails.
+     */
+    private static function deserializeMap(array $data, array $type): array
+    {
+        $keyType = array_key_first($type);
+        $valueType = $type[$keyType];
+        $result = [];
+
+        foreach ($data as $key => $item) {
+            $key = Utils::castKey($key, (string)$keyType);
+            $result[$key] = self::deserializeValue($item, $valueType);
+        }
+
+        return $result;
+    }
+
+    /**
+     * Deserializes a list (indexed array) with a defined value type.
+     *
+     * @param array<int, mixed> $data The list to deserialize.
+     * @param array<int, mixed> $type The type definition for the list.
+     * @return array<int, mixed> The deserialized list.
+     * @throws JsonException If deserialization fails.
+     */
+    private static function deserializeList(array $data, array $type): array
+    {
+        $valueType = $type[0];
+        return array_map(fn ($item) => self::deserializeValue($item, $valueType), $data);
+    }
+}
diff --git a/seed/php-model/server-sent-events/src/Core/JsonEncoder.php b/seed/php-model/server-sent-events/src/Core/JsonEncoder.php
new file mode 100644
index 00000000000..ba5191a8068
--- /dev/null
+++ b/seed/php-model/server-sent-events/src/Core/JsonEncoder.php
@@ -0,0 +1,20 @@
+<?php
+
+namespace Seed\Core;
+
+use JsonException;
+
+class JsonEncoder
+{
+    /**
+     * Encodes a PHP value into JSON string.
+     *
+     * @param mixed $value The PHP value to encode.
+     * @return string The encoded string.
+     * @throws JsonException
+     */
+    public static function encode(mixed $value): string
+    {
+        return json_encode($value, JSON_THROW_ON_ERROR);
+    }
+}
diff --git a/seed/php-model/server-sent-events/src/Core/JsonProperty.php b/seed/php-model/server-sent-events/src/Core/JsonProperty.php
new file mode 100644
index 00000000000..06a436fff9b
--- /dev/null
+++ b/seed/php-model/server-sent-events/src/Core/JsonProperty.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace Seed\Core;
+
+use Attribute;
+
+#[Attribute(Attribute::TARGET_PROPERTY)]
+class JsonProperty
+{
+    public function __construct(public string $name)
+    {
+    }
+}
diff --git a/seed/php-model/server-sent-events/src/Core/JsonSerializer.php b/seed/php-model/server-sent-events/src/Core/JsonSerializer.php
new file mode 100644
index 00000000000..eae0c087441
--- /dev/null
+++ b/seed/php-model/server-sent-events/src/Core/JsonSerializer.php
@@ -0,0 +1,173 @@
+<?php
+
+namespace Seed\Core;
+
+use DateTime;
+use Exception;
+use JsonException;
+use JsonSerializable;
+
+class JsonSerializer
+{
+    /**
+     * Serializes a DateTime object into a string using the date format.
+     *
+     * @param DateTime $date The DateTime object to serialize.
+     * @return string The serialized date string.
+     */
+    public static function serializeDate(DateTime $date): string
+    {
+        return $date->format(Constant::DateFormat);
+    }
+
+    /**
+     * Serializes a DateTime object into a string using the date-time format.
+     *
+     * @param DateTime $date The DateTime object to serialize.
+     * @return string The serialized date-time string.
+     */
+    public static function serializeDateTime(DateTime $date): string
+    {
+        return $date->format(Constant::DateTimeFormat);
+    }
+
+    /**
+     * Serializes an array based on type annotations (either a list or map).
+     *
+     * @param mixed[]|array<string, mixed> $data The array to be serialized.
+     * @param mixed[]|array<string, mixed> $type The type definition from the annotation.
+     * @return mixed[]|array<string, mixed> The serialized array.
+     * @throws JsonException If serialization fails.
+     */
+    public static function serializeArray(array $data, array $type): array
+    {
+        return Utils::isMapType($type)
+            ? self::serializeMap($data, $type)
+            : self::serializeList($data, $type);
+    }
+
+    /**
+     * Serializes a value based on its type definition.
+     *
+     * @param mixed $data The value to serialize.
+     * @param mixed $type The type definition.
+     * @return mixed The serialized value.
+     * @throws JsonException If serialization fails.
+     */
+    private static function serializeValue(mixed $data, mixed $type): mixed
+    {
+        if ($type instanceof Union) {
+            foreach ($type->types as $unionType) {
+                try {
+                    return self::serializeSingleValue($data, $unionType);
+                } catch (Exception) {
+                    continue;
+                }
+            }
+            throw new JsonException("Cannot serialize value with any of the union types.");
+        }
+
+        if (is_array($type)) {
+            return self::serializeArray((array)$data, $type);
+        }
+
+        if (gettype($type) != "string") {
+            throw new JsonException("Unexpected non-string type.");
+        }
+
+        return self::serializeSingleValue($data, $type);
+    }
+
+    /**
+     * Serializes a single value based on its type.
+     *
+     * @param mixed $data The value to serialize.
+     * @param string $type The expected type.
+     * @return mixed The serialized value.
+     * @throws JsonException If serialization fails.
+     */
+    private static function serializeSingleValue(mixed $data, string $type): mixed
+    {
+        if ($type === 'null' && $data === null) {
+            return null;
+        }
+
+        if (($type === 'date' || $type === 'datetime') && $data instanceof DateTime) {
+            return $type === 'date' ? self::serializeDate($data) : self::serializeDateTime($data);
+        }
+
+        if ($type === 'mixed') {
+            return $data;
+        }
+
+        if (class_exists($type) && $data instanceof $type) {
+            return self::serializeObject($data);
+        }
+
+        // Handle floats as a special case since gettype($data) returns "double" for float values in PHP.
+        if ($type === 'float' && is_float($data)) {
+            return $data;
+        }
+
+        if (gettype($data) === $type) {
+            return $data;
+        }
+
+        throw new JsonException("Unable to serialize value of type '" . gettype($data) . "' as '$type'.");
+    }
+
+    /**
+     * Serializes an object to a JSON-serializable format.
+     *
+     * @param object $data The object to serialize.
+     * @return mixed The serialized data.
+     * @throws JsonException If the object does not implement JsonSerializable.
+     */
+    public static function serializeObject(object $data): mixed
+    {
+        if (!is_subclass_of($data, JsonSerializable::class)) {
+            $type = get_class($data);
+            throw new JsonException("Class $type must implement JsonSerializable.");
+        }
+        return $data->jsonSerialize();
+    }
+
+    /**
+     * Serializes a map (associative array) with defined key and value types.
+     *
+     * @param array<string, mixed> $data The associative array to serialize.
+     * @param array<string, mixed> $type The type definition for the map.
+     * @return array<string, mixed> The serialized map.
+     * @throws JsonException If serialization fails.
+     */
+    private static function serializeMap(array $data, array $type): array
+    {
+        $keyType = array_key_first($type);
+        if ($keyType === null) {
+            throw new JsonException("Unexpected no key in ArrayType.");
+        }
+        $valueType = $type[$keyType];
+        $result = [];
+
+        foreach ($data as $key => $item) {
+            $key = Utils::castKey($key, $keyType);
+            $result[$key] = self::serializeValue($item, $valueType);
+        }
+
+        return $result;
+    }
+
+    /**
+     * Serializes a list (indexed array) where only the value type is defined.
+     *
+     * @param array<int, mixed> $data The list to serialize.
+     * @param array<int, mixed> $type The type definition for the list.
+     * @return array<int, mixed> The serialized list.
+     * @throws JsonException If serialization fails.
+     */
+    private static function serializeList(array $data, array $type): array
+    {
+        $valueType = $type[0];
+        return array_map(fn ($item) => self::serializeValue($item, $valueType), $data);
+    }
+}
diff --git a/seed/php-model/server-sent-events/src/Core/SerializableType.php b/seed/php-model/server-sent-events/src/Core/SerializableType.php
new file mode 100644
index 00000000000..ecb6c6abc19
--- /dev/null
+++ b/seed/php-model/server-sent-events/src/Core/SerializableType.php
@@ -0,0 +1,165 @@
+<?php
+
+namespace Seed\Core;
+
+use DateTime;
+use Exception;
+use JsonException;
+use ReflectionNamedType;
+use ReflectionProperty;
+
+/**
+ * Provides generic serialization and deserialization methods.
+ */
+abstract class SerializableType implements \JsonSerializable
+{
+    /**
+     * Serializes the object to a JSON string.
+     *
+     * @return string JSON-encoded string representation of the object.
+     * @throws Exception If encoding fails.
+     */
+    public function toJson(): string
+    {
+        $serializedObject = $this->jsonSerialize();
+        $encoded = JsonEncoder::encode($serializedObject);
+        if (!$encoded) {
+            throw new Exception("Could not encode type");
+        }
+        return $encoded;
+    }
+
+    /**
+     * Serializes the object to an array.
+     *
+     * @return mixed[] Array representation of the object.
+     * @throws JsonException If serialization fails.
+     */
+    public function jsonSerialize(): array
+    {
+        $result = [];
+        $reflectionClass = new \ReflectionClass($this);
+
+        foreach ($reflectionClass->getProperties() as $property) {
+            $jsonKey = self::getJsonKey($property);
+            if ($jsonKey == null) {
+                continue;
+            }
+            $value = $property->getValue($this);
+
+            // Handle DateTime properties
+            $dateTypeAttr = $property->getAttributes(DateType::class)[0] ?? null;
+            if ($dateTypeAttr && $value instanceof DateTime) {
+                $dateType = $dateTypeAttr->newInstance()->type;
+                $value = ($dateType === DateType::TYPE_DATE)
+                    ? JsonSerializer::serializeDate($value)
+                    : JsonSerializer::serializeDateTime($value);
+            }
+
+            // Handle arrays with type annotations
+            $arrayTypeAttr = $property->getAttributes(ArrayType::class)[0] ?? null;
+            if ($arrayTypeAttr && is_array($value)) {
+                $arrayType = $arrayTypeAttr->newInstance()->type;
+                $value = JsonSerializer::serializeArray($value, $arrayType);
+            }
+
+            // Handle object
+            if (is_object($value)) {
+                $value = JsonSerializer::serializeObject($value);
+            }
+
+            if ($value !== null) {
+                $result[$jsonKey] = $value;
+            }
+        }
+
+        return $result;
+    }
+
+    /**
+     * Deserializes a JSON string into an instance of the calling class.
+     *
+     * @param string $json JSON string to deserialize.
+     * @return static Deserialized object.
+     * @throws JsonException If decoding fails or the result is not an array.
+     * @throws Exception If deserialization fails.
+     */
+    public static function fromJson(string $json): static
+    {
+        $decodedJson = JsonDecoder::decode($json);
+        if (!is_array($decodedJson)) {
+            throw new JsonException("Unexpected non-array decoded type: " . gettype($decodedJson));
+        }
+        return self::jsonDeserialize($decodedJson);
+    }
+
+    /**
+     * Deserializes an array into an instance of the calling class.
+     *
+     * @param array<string, mixed> $data Array data to deserialize.
+     * @return static Deserialized object.
+     * @throws JsonException If deserialization fails.
+     */
+    public static function jsonDeserialize(array $data): static
+    {
+        $reflectionClass = new \ReflectionClass(static::class);
+        $constructor = $reflectionClass->getConstructor();
+
+        if ($constructor === null) {
+            throw new JsonException("No constructor found.");
+        }
+
+        $args = [];
+        foreach ($reflectionClass->getProperties() as $property) {
+            $jsonKey = self::getJsonKey($property) ?? $property->getName();
+
+            if (array_key_exists($jsonKey, $data)) {
+                $value = $data[$jsonKey];
+
+                // Handle DateType annotation
+                $dateTypeAttr = $property->getAttributes(DateType::class)[0] ?? null;
+                if ($dateTypeAttr) {
+                    $dateType = $dateTypeAttr->newInstance()->type;
+                    if (!is_string($value)) {
+                        throw new JsonException("Unexpected non-string type for date.");
+                    }
+                    $value = ($dateType === DateType::TYPE_DATE)
+                        ? JsonDeserializer::deserializeDate($value)
+                        : JsonDeserializer::deserializeDateTime($value);
+                }
+
+                // Handle ArrayType annotation
+                $arrayTypeAttr = $property->getAttributes(ArrayType::class)[0] ?? null;
+                if (is_array($value) && $arrayTypeAttr) {
+                    $arrayType = $arrayTypeAttr->newInstance()->type;
+                    $value = JsonDeserializer::deserializeArray($value, $arrayType);
+                }
+
+                // Handle object
+                $type = $property->getType();
+                if (is_array($value) && $type instanceof ReflectionNamedType && !$type->isBuiltin()) {
+                    $value = JsonDeserializer::deserializeObject($value, $type->getName());
+                }
+
+                $args[$property->getName()] = $value;
+            } else {
+                $defaultValue = $property->getDefaultValue() ?? null;
+                $args[$property->getName()] = $defaultValue;
+            }
+        }
+        // @phpstan-ignore-next-line
+        return new static($args);
+    }
+
+    /**
+     * Retrieves the JSON key associated with a property.
+     *
+     * @param ReflectionProperty $property The reflection property.
+     * @return ?string The JSON key, or null if not available.
+     */
+    private static function getJsonKey(ReflectionProperty $property): ?string
+    {
+        $jsonPropertyAttr = $property->getAttributes(JsonProperty::class)[0] ?? null;
+        return $jsonPropertyAttr?->newInstance()?->name;
+    }
+}
diff --git a/seed/php-model/server-sent-events/src/Core/Union.php b/seed/php-model/server-sent-events/src/Core/Union.php
new file mode 100644
index 00000000000..8608d2cae49
--- /dev/null
+++ b/seed/php-model/server-sent-events/src/Core/Union.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace Seed\Core;
+
+class Union
+{
+    /**
+     * @var string[]
+     */
+    public array $types;
+
+    public function __construct(string ...$strings)
+    {
+        $this->types = $strings;
+    }
+
+    public function __toString(): string
+    {
+        return implode(' | ', $this->types);
+    }
+}
diff --git a/seed/php-model/server-sent-events/src/Core/Utils.php b/seed/php-model/server-sent-events/src/Core/Utils.php
new file mode 100644
index 00000000000..74416068d02
--- /dev/null
+++ b/seed/php-model/server-sent-events/src/Core/Utils.php
@@ -0,0 +1,61 @@
+<?php
+
+namespace Seed\Core;
+
+use DateTime;
+use Exception;
+use JsonException;
+
+class Utils
+{
+    /**
+     * Determines if the given type represents a map.
+     *
+     * @param mixed[]|array<string, mixed> $type The type definition from the annotation.
+     * @return bool True if the type is a map, false if it's a list.
+     */
+    public static function isMapType(array $type): bool
+    {
+        return count($type) === 1 && !array_is_list($type);
+    }
+
+    /**
+     * Casts the key to the appropriate type based on the key type.
+     *
+     * @param mixed $key The key to be cast.
+     * @param string $keyType The type to cast the key to ('string', 'integer', 'float').
+     * @return mixed The casted key.
+     * @throws JsonException
+     */
+    public static function castKey(mixed $key, string $keyType): mixed
+    {
+        if (!is_scalar($key)) {
+            throw new JsonException("Key must be a scalar type.");
+        }
+        return match ($keyType) {
+            'integer' => (int)$key,
+            'float' => (float)$key,
+            'string' => (string)$key,
+            default => $key,
+        };
+    }
+
+    /**
+     * Returns a human-readable representation of the input's type.
+     *
+     * @param mixed $input The input value to determine the type of.
+     * @return string A readable description of the input type.
+     */
+    public static function getReadableType(mixed $input): string
+    {
+        if (is_object($input)) {
+            return get_class($input);
+        } elseif (is_array($input)) {
+            return 'array(' . count($input) . ' items)';
+        } elseif (is_null($input)) {
+            return 'null';
+        } else {
+            return gettype($input);
+        }
+    }
+}
diff --git a/seed/php-model/server-sent-events/tests/Seed/Core/DateArrayTypeTest.php b/seed/php-model/server-sent-events/tests/Seed/Core/DateArrayTypeTest.php
new file mode 100644
index 00000000000..8d93afc9e44
--- /dev/null
+++ b/seed/php-model/server-sent-events/tests/Seed/Core/DateArrayTypeTest.php
@@ -0,0 +1,55 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+use Seed\Core\ArrayType;
+use DateTime;
+
+class DateArrayType extends SerializableType
+{
+    /**
+     * @var string[] $dates
+     */
+    #[ArrayType(['date'])]
+    #[JsonProperty('dates')]
+    public array $dates;
+
+    /**
+     * @param array{
+     *   dates: string[],
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->dates = $values['dates'];
+    }
+}
+
+class DateArrayTypeTest extends TestCase
+{
+    public function testDateTimeTypesInArrays(): void
+    {
+        $data = [
+            'dates' => ['2023-01-01', '2023-02-01', '2023-03-01']
+        ];
+
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+
+        $object = DateArrayType::fromJson($json);
+
+        $this->assertInstanceOf(DateTime::class, $object->dates[0], 'dates[0] should be a DateTime instance.');
+        $this->assertEquals('2023-01-01', $object->dates[0]->format('Y-m-d'), 'dates[0] should have the correct date.');
+        $this->assertInstanceOf(DateTime::class, $object->dates[1], 'dates[1] should be a DateTime instance.');
+        $this->assertEquals('2023-02-01', $object->dates[1]->format('Y-m-d'), 'dates[1] should have the correct date.');
+        $this->assertInstanceOf(DateTime::class, $object->dates[2], 'dates[2] should be a DateTime instance.');
+        $this->assertEquals('2023-03-01', $object->dates[2]->format('Y-m-d'), 'dates[2] should have the correct date.');
+
+        $serializedJson = $object->toJson();
+
+        $this->assertJsonStringEqualsJsonString($json, $serializedJson, 'Serialized JSON does not match original JSON for dates array.');
+    }
+}
diff --git a/seed/php-model/server-sent-events/tests/Seed/Core/EmptyArraysTest.php b/seed/php-model/server-sent-events/tests/Seed/Core/EmptyArraysTest.php
new file mode 100644
index 00000000000..b44f3d093e6
--- /dev/null
+++ b/seed/php-model/server-sent-events/tests/Seed/Core/EmptyArraysTest.php
@@ -0,0 +1,73 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+use Seed\Core\ArrayType;
+use Seed\Core\Union;
+
+class EmptyArraysType extends SerializableType
+{
+    /**
+     * @var string[] $emptyStringArray
+     */
+    #[ArrayType(['string'])]
+    #[JsonProperty('empty_string_array')]
+    public array $emptyStringArray;
+
+    /**
+     * @var array<string, string|null> $emptyMapArray
+     */
+    #[JsonProperty('empty_map_array')]
+    #[ArrayType(['integer' => new Union('string', 'null')])]
+    public array $emptyMapArray;
+
+    /**
+     * @var array<string|null> $emptyDatesArray
+     */
+    #[ArrayType([new Union('date', 'null')])]
+    #[JsonProperty('empty_dates_array')]
+    public array $emptyDatesArray;
+
+    /**
+     * @param array{
+     *   emptyStringArray: string[],
+     *   emptyMapArray: array<string, string|null>,
+     *   emptyDatesArray: array<string|null>,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->emptyStringArray = $values['emptyStringArray'];
+        $this->emptyMapArray = $values['emptyMapArray'];
+        $this->emptyDatesArray = $values['emptyDatesArray'];
+    }
+}
+
+class EmptyArraysTest extends TestCase
+{
+    public function testEmptyArrays(): void
+    {
+        $data = [
+            'empty_string_array' => [],
+            'empty_map_array' => [],
+            'empty_dates_array' => []
+        ];
+
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+
+        $object = EmptyArraysType::fromJson($json);
+
+        $serializedJson = $object->toJson();
+
+        $this->assertJsonStringEqualsJsonString($json, $serializedJson, 'Serialized JSON does not match original JSON for EmptyArraysType.');
+
+        // Check that arrays are empty
+        $this->assertEmpty($object->emptyStringArray, 'empty_string_array should be empty.');
+        $this->assertEmpty($object->emptyMapArray, 'empty_map_array should be empty.');
+        $this->assertEmpty($object->emptyDatesArray, 'empty_dates_array should be empty.');
+    }
+}
diff --git a/seed/php-model/server-sent-events/tests/Seed/Core/EnumTest.php b/seed/php-model/server-sent-events/tests/Seed/Core/EnumTest.php
new file mode 100644
index 00000000000..ef5b8484dfd
--- /dev/null
+++ b/seed/php-model/server-sent-events/tests/Seed/Core/EnumTest.php
@@ -0,0 +1,76 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use JsonSerializable;
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+use Seed\Core\ArrayType;
+
+enum Shape: string implements JsonSerializable
+{
+    case Square = "SQUARE";
+    case Circle = "CIRCLE";
+    case Triangle = "TRIANGLE";
+
+    /**
+     * @return string
+     */
+    public function jsonSerialize(): string
+    {
+        return $this->value;
+    }
+}
+
+class ShapeType extends SerializableType
+{
+    /**
+     * @var Shape $shape
+     */
+    #[JsonProperty('shape')]
+    public Shape $shape;
+
+    /**
+     * @var Shape[] $shapes
+     */
+    #[ArrayType([Shape::class])]
+    #[JsonProperty('shapes')]
+    public array $shapes;
+
+    /**
+     * @param Shape $shape
+     * @param Shape[] $shapes
+     */
+    public function __construct(
+        Shape $shape,
+        array $shapes,
+    ) {
+        $this->shape = $shape;
+        $this->shapes = $shapes;
+    }
+}
+
+class EnumTest extends TestCase
+{
+    public function testShapeEnumSerialization(): void
+    {
+        $object = new ShapeType(
+            Shape::Circle,
+            [Shape::Square, Shape::Circle, Shape::Triangle]
+        );
+
+        $expectedJson = json_encode([
+            'shape' => 'CIRCLE',
+            'shapes' => ['SQUARE', 'CIRCLE', 'TRIANGLE']
+        ], JSON_THROW_ON_ERROR);
+
+        $serializedJson = $object->toJson();
+
+        $this->assertJsonStringEqualsJsonString(
+            $expectedJson,
+            $serializedJson,
+            'Serialized JSON does not match expected JSON for shape and shapes properties.'
+        );
+    }
+}
diff --git a/seed/php-model/server-sent-events/tests/Seed/Core/InvalidTypesTest.php b/seed/php-model/server-sent-events/tests/Seed/Core/InvalidTypesTest.php
new file mode 100644
index 00000000000..67bfd235b2f
--- /dev/null
+++ b/seed/php-model/server-sent-events/tests/Seed/Core/InvalidTypesTest.php
@@ -0,0 +1,45 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+
+class InvalidType extends SerializableType
+{
+    /**
+     * @var int $integerProperty
+     */
+    #[JsonProperty('integer_property')]
+    public int $integerProperty;
+
+    /**
+     * @param array{
+     *   integerProperty: int,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->integerProperty = $values['integerProperty'];
+    }
+}
+
+class InvalidTypesTest extends TestCase
+{
+    public function testInvalidTypesThrowExceptions(): void
+    {
+        // Create test data with invalid type for integer_property (string instead of int)
+        $data = [
+            'integer_property' => 'not_an_integer'
+        ];
+
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+
+        $this->expectException(\TypeError::class);
+
+        // Attempt to deserialize invalid data
+        InvalidType::fromJson($json);
+    }
+}
diff --git a/seed/php-model/server-sent-events/tests/Seed/Core/MixedDateArrayTypeTest.php b/seed/php-model/server-sent-events/tests/Seed/Core/MixedDateArrayTypeTest.php
new file mode 100644
index 00000000000..3bf18aec25b
--- /dev/null
+++ b/seed/php-model/server-sent-events/tests/Seed/Core/MixedDateArrayTypeTest.php
@@ -0,0 +1,60 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+use Seed\Core\ArrayType;
+use Seed\Core\Union;
+use DateTime;
+
+class MixedDateArrayType extends SerializableType
+{
+    /**
+     * @var array<int, datetime|string|null> $mixedDates
+     */
+    #[ArrayType(['integer' => new Union('datetime', 'string', 'null')])]
+    #[JsonProperty('mixed_dates')]
+    public array $mixedDates;
+
+    /**
+     * @param array{
+     *   mixedDates: array<int, datetime|string|null>,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->mixedDates = $values['mixedDates'];
+    }
+}
+
+class MixedDateArrayTypeTest extends TestCase
+{
+    public function testDateTimeTypesInUnionArrays(): void
+    {
+        $data = [
+            'mixed_dates' => [
+                1 => '2023-01-01T12:00:00+00:00',
+                2 => null,
+                3 => 'Some String'
+            ]
+        ];
+
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+
+        $object = MixedDateArrayType::fromJson($json);
+
+        $this->assertInstanceOf(DateTime::class, $object->mixedDates[1], 'mixed_dates[1] should be a DateTime instance.');
+        $this->assertEquals('2023-01-01 12:00:00', $object->mixedDates[1]->format('Y-m-d H:i:s'), 'mixed_dates[1] should have the correct datetime.');
+
+        $this->assertNull($object->mixedDates[2], 'mixed_dates[2] should be null.');
+
+        $this->assertEquals('Some String', $object->mixedDates[3], 'mixed_dates[3] should be "Some String".');
+
+        $serializedJson = $object->toJson();
+
+        $this->assertJsonStringEqualsJsonString($json, $serializedJson, 'Serialized JSON does not match original JSON for mixed_dates.');
+    }
+}
diff --git a/seed/php-model/server-sent-events/tests/Seed/Core/NestedUnionArrayTypeTest.php b/seed/php-model/server-sent-events/tests/Seed/Core/NestedUnionArrayTypeTest.php
new file mode 100644
index 00000000000..4667ecafcb9
--- /dev/null
+++ b/seed/php-model/server-sent-events/tests/Seed/Core/NestedUnionArrayTypeTest.php
@@ -0,0 +1,99 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\Constant;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+use Seed\Core\ArrayType;
+use Seed\Core\Union;
+use DateTime;
+
+// Supporting Classes
+
+class TestNestedType extends SerializableType
+{
+    /**
+     * @var string $nestedProperty
+     */
+    #[JsonProperty('nested_property')]
+    public string $nestedProperty;
+
+    /**
+     * @param array{
+     *   nestedProperty: string,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->nestedProperty = $values['nestedProperty'];
+    }
+}
+
+class NestedUnionArrayType extends SerializableType
+{
+    /**
+     * @var array<int, array<int, TestNestedType|null|string>> $nestedArray
+     */
+    #[ArrayType(['integer' => ['integer' => new Union(TestNestedType::class, 'null', 'date')]])]
+    #[JsonProperty('nested_array')]
+    public array $nestedArray;
+
+    /**
+     * @param array{
+     *   nestedArray: array<int, array<int, TestNestedType|null|string>>,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->nestedArray = $values['nestedArray'];
+    }
+}
+
+class NestedUnionArrayTypeTest extends TestCase
+{
+    public function testNestedUnionTypesInArrays(): void
+    {
+        $data = [
+            'nested_array' => [
+                1 => [
+                    1 => ['nested_property' => 'Nested One'],
+                    2 => null,
+                    4 => '2023-01-02'
+                ],
+                2 => [
+                    5 => ['nested_property' => 'Nested Two'],
+                    7 => '2023-02-02'
+                ]
+            ]
+        ];
+
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+
+        $object = NestedUnionArrayType::fromJson($json);
+
+        // Level 1
+        $this->assertInstanceOf(TestNestedType::class, $object->nestedArray[1][1], 'nested_array[1][1] should be an instance of TestNestedType.');
+        $this->assertEquals('Nested One', $object->nestedArray[1][1]->nestedProperty, 'nested_array[1][1]->nestedProperty should match the original data.');
+
+        $this->assertNull($object->nestedArray[1][2], 'nested_array[1][2] should be null.');
+
+        // ensure dates are set with the default time
+        $this->assertInstanceOf(DateTime::class, $object->nestedArray[1][4], 'nested_array[1][4] should be a DateTime instance.');
+        $this->assertEquals('2023-01-02T00:00:00+00:00', $object->nestedArray[1][4]->format(Constant::DateTimeFormat), 'nested_array[1][4] should have the correct datetime.');
+
+        // Level 2
+        $this->assertInstanceOf(TestNestedType::class, $object->nestedArray[2][5], 'nested_array[2][5] should be an instance of TestNestedType.');
+        $this->assertEquals('Nested Two', $object->nestedArray[2][5]->nestedProperty, 'nested_array[2][5]->nestedProperty should match the original data.');
+
+        $this->assertInstanceOf(DateTime::class, $object->nestedArray[2][7], 'nested_array[1][4] should be a DateTime instance.');
+        $this->assertEquals('2023-02-02', $object->nestedArray[2][7]->format('Y-m-d'), 'nested_array[1][4] should have the correct date.');
+
+        $serializedJson = $object->toJson();
+
+        $this->assertJsonStringEqualsJsonString($json, $serializedJson, 'Serialized JSON does not match original JSON for nested_array.');
+    }
+}
diff --git a/seed/php-model/server-sent-events/tests/Seed/Core/NullPropertyTypeTest.php b/seed/php-model/server-sent-events/tests/Seed/Core/NullPropertyTypeTest.php
new file mode 100644
index 00000000000..134296f56e3
--- /dev/null
+++ b/seed/php-model/server-sent-events/tests/Seed/Core/NullPropertyTypeTest.php
@@ -0,0 +1,50 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+
+class NullPropertyType extends SerializableType
+{
+    /**
+     * @var string $nonNullProperty
+     */
+    #[JsonProperty('non_null_property')]
+    public string $nonNullProperty;
+
+    /**
+     * @var string|null $nullProperty
+     */
+    #[JsonProperty('null_property')]
+    public ?string $nullProperty;
+
+    /**
+     * @param array{
+     *   nonNullProperty: string,
+     *   nullProperty?: string|null,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->nonNullProperty = $values['nonNullProperty'];
+        $this->nullProperty = $values['nullProperty'] ?? null;
+    }
+}
+
+class NullPropertyTypeTest extends TestCase
+{
+    public function testNullPropertiesAreOmitted(): void
+    {
+        $object = new NullPropertyType(["nonNullProperty" => "Test String", "nullProperty" => null]);
+
+        $serializedObject = $object->jsonSerialize();
+
+        $this->assertArrayHasKey('non_null_property', $serializedObject, 'non_null_property should be present in the serialized JSON.');
+        $this->assertArrayNotHasKey('null_property', $serializedObject, 'null_property should be omitted from the serialized JSON.');
+
+        $this->assertEquals('Test String', $serializedObject['non_null_property'], 'non_null_property should have the correct value.');
+    }
+}
diff --git a/seed/php-model/server-sent-events/tests/Seed/Core/NullableArrayTypeTest.php b/seed/php-model/server-sent-events/tests/Seed/Core/NullableArrayTypeTest.php
new file mode 100644
index 00000000000..bf6345e5c6f
--- /dev/null
+++ b/seed/php-model/server-sent-events/tests/Seed/Core/NullableArrayTypeTest.php
@@ -0,0 +1,50 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+use Seed\Core\ArrayType;
+use Seed\Core\Union;
+
+class NullableArrayType extends SerializableType
+{
+    /**
+     * @var array<string|null> $nullableStringArray
+     */
+    #[ArrayType([new Union('string', 'null')])]
+    #[JsonProperty('nullable_string_array')]
+    public array $nullableStringArray;
+
+    /**
+     * @param array{
+     *   nullableStringArray: array<string|null>,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->nullableStringArray = $values['nullableStringArray'];
+    }
+}
+
+class NullableArrayTypeTest extends TestCase
+{
+    public function testNullableTypesInArrays(): void
+    {
+        $data = [
+            'nullable_string_array' => ['one', null, 'three']
+        ];
+
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+
+        $object = NullableArrayType::fromJson($json);
+
+        $this->assertEquals(['one', null, 'three'], $object->nullableStringArray, 'nullable_string_array should match the original data.');
+
+        $serializedJson = $object->toJson();
+
+        $this->assertJsonStringEqualsJsonString($json, $serializedJson, 'Serialized JSON does not match original JSON for nullable_string_array.');
+    }
+}
diff --git a/seed/php-model/server-sent-events/tests/Seed/Core/ScalarTypesTest.php b/seed/php-model/server-sent-events/tests/Seed/Core/ScalarTypesTest.php
new file mode 100644
index 00000000000..899e949836c
--- /dev/null
+++ b/seed/php-model/server-sent-events/tests/Seed/Core/ScalarTypesTest.php
@@ -0,0 +1,121 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+use Seed\Core\ArrayType;
+use Seed\Core\Union;
+
+class ScalarTypesTestType extends SerializableType
+{
+    /**
+     * @var int $integerProperty
+     */
+    #[JsonProperty('integer_property')]
+    public int $integerProperty;
+
+    /**
+     * @var float $floatProperty
+     */
+    #[JsonProperty('float_property')]
+    public float $floatProperty;
+    /**
+     * @var float $otherFloatProperty
+     */
+    #[JsonProperty('other_float_property')]
+    public float $otherFloatProperty;
+
+    /**
+     * @var bool $booleanProperty
+     */
+    #[JsonProperty('boolean_property')]
+    public bool $booleanProperty;
+
+    /**
+     * @var string $stringProperty
+     */
+    #[JsonProperty('string_property')]
+    public string $stringProperty;
+
+    /**
+     * @var array<int|float> $intFloatArray
+     */
+    #[ArrayType([new Union('integer', 'float')])]
+    #[JsonProperty('int_float_array')]
+    public array $intFloatArray;
+
+    /**
+     * @var array<float> $floatArray
+     */
+    #[ArrayType(['float'])]
+    #[JsonProperty('float_array')]
+    public array $floatArray;
+
+    /**
+     * @var bool|null $nullableBooleanProperty
+     */
+    #[JsonProperty('nullable_boolean_property')]
+    public ?bool $nullableBooleanProperty;
+
+    /**
+     * @param array{
+     *   integerProperty: int,
+     *   floatProperty: float,
+     *   otherFloatProperty: float,
+     *   booleanProperty: bool,
+     *   stringProperty: string,
+     *   intFloatArray: array<int|float>,
+     *   floatArray: array<float>,
+     *   nullableBooleanProperty?: bool|null,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->integerProperty = $values['integerProperty'];
+        $this->floatProperty = $values['floatProperty'];
+        $this->otherFloatProperty = $values['otherFloatProperty'];
+        $this->booleanProperty = $values['booleanProperty'];
+        $this->stringProperty = $values['stringProperty'];
+        $this->intFloatArray = $values['intFloatArray'];
+        $this->floatArray = $values['floatArray'];
+        $this->nullableBooleanProperty = $values['nullableBooleanProperty'] ?? null;
+    }
+}
+
+class ScalarTypesTest extends TestCase
+{
+    public function testAllScalarTypesIncludingFloat(): void
+    {
+        // Create test data
+        $data = [
+            'integer_property' => 42,
+            'float_property' => 3.14159,
+            'other_float_property' => 3,
+            'boolean_property' => true,
+            'string_property' => 'Hello, World!',
+            'int_float_array' => [1, 2.5, 3, 4.75],
+            'float_array' => [1, 2, 3, 4] // ensure we handle "integer-looking" floats
+        ];
+
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+
+        $object = ScalarTypesTestType::fromJson($json);
+
+        $serializedJson = $object->toJson();
+
+        $this->assertJsonStringEqualsJsonString($json, $serializedJson, 'Serialized JSON does not match original JSON for ScalarTypesTest.');
+
+        // Check scalar properties
+        $this->assertEquals(42, $object->integerProperty, 'integer_property should be 42.');
+        $this->assertEquals(3.14159, $object->floatProperty, 'float_property should be 3.14159.');
+        $this->assertTrue($object->booleanProperty, 'boolean_property should be true.');
+        $this->assertEquals('Hello, World!', $object->stringProperty, 'string_property should be "Hello, World!".');
+        $this->assertNull($object->nullableBooleanProperty, 'nullable_boolean_property should be null.');
+
+        // Check int_float_array
+        $this->assertEquals([1, 2.5, 3, 4.75], $object->intFloatArray, 'int_float_array should match the original data.');
+    }
+}
diff --git a/seed/php-model/server-sent-events/tests/Seed/Core/TestTypeTest.php b/seed/php-model/server-sent-events/tests/Seed/Core/TestTypeTest.php
new file mode 100644
index 00000000000..8e7ca1b825c
--- /dev/null
+++ b/seed/php-model/server-sent-events/tests/Seed/Core/TestTypeTest.php
@@ -0,0 +1,201 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+use Seed\Core\DateType;
+use Seed\Core\ArrayType;
+use DateTime;
+use Seed\Core\Union;
+
+class TestNestedType1 extends SerializableType
+{
+    /**
+     * @var DateTime $nestedProperty
+     */
+    #[JsonProperty('nested_property')]
+    #[DateType(DateType::TYPE_DATE)]
+    public DateTime $nestedProperty;
+
+    /**
+     * @param array{
+     *   nestedProperty: DateTime,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->nestedProperty = $values['nestedProperty'];
+    }
+}
+
+class TestType extends SerializableType
+{
+    /**
+     * @var TestNestedType1 nestedType
+     */
+    #[JsonProperty('nested_type')]
+    public TestNestedType1 $nestedType;    /**
+
+     * @var string $simpleProperty
+     */
+    #[JsonProperty('simple_property')]
+    public string $simpleProperty;
+
+    /**
+     * @var DateTime $dateProperty
+     */
+    #[DateType(DateType::TYPE_DATE)]
+    #[JsonProperty('date_property')]
+    public DateTime $dateProperty;
+
+    /**
+     * @var DateTime $datetimeProperty
+     */
+    #[DateType(DateType::TYPE_DATETIME)]
+    #[JsonProperty('datetime_property')]
+    public DateTime $datetimeProperty;
+
+    /**
+     * @var array<string> $stringArray
+     */
+    #[ArrayType(['string'])]
+    #[JsonProperty('string_array')]
+    public array $stringArray;
+
+    /**
+     * @var array<string, int> $mapProperty
+     */
+    #[ArrayType(['string' => 'integer'])]
+    #[JsonProperty('map_property')]
+    public array $mapProperty;
+
+    /**
+     * @var array<int, TestNestedType1|null> $objectArray
+     */
+    #[ArrayType(['integer' => new Union(TestNestedType1::class, 'null')])]
+    #[JsonProperty('object_array')]
+    public array $objectArray;
+
+    /**
+     * @var array<int, array<int, string|null>> $nestedArray
+     */
+    #[ArrayType(['integer' => ['integer' => new Union('string', 'null')]])]
+    #[JsonProperty('nested_array')]
+    public array $nestedArray;
+
+    /**
+     * @var array<string|null> $datesArray
+     */
+    #[ArrayType([new Union('date', 'null')])]
+    #[JsonProperty('dates_array')]
+    public array $datesArray;
+
+    /**
+     * @var string|null $nullableProperty
+     */
+    #[JsonProperty('nullable_property')]
+    public ?string $nullableProperty;
+
+    /**
+     * @param array{
+     *   nestedType: TestNestedType1,
+     *   simpleProperty: string,
+     *   dateProperty: DateTime,
+     *   datetimeProperty: DateTime,
+     *   stringArray: array<string>,
+     *   mapProperty: array<string, int>,
+     *   objectArray: array<int, TestNestedType1|null>,
+     *   nestedArray: array<int, array<int, string|null>>,
+     *   datesArray: array<string|null>,
+     *   nullableProperty?: string|null,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->nestedType = $values['nestedType'];
+        $this->simpleProperty = $values['simpleProperty'];
+        $this->dateProperty = $values['dateProperty'];
+        $this->datetimeProperty = $values['datetimeProperty'];
+        $this->stringArray = $values['stringArray'];
+        $this->mapProperty = $values['mapProperty'];
+        $this->objectArray = $values['objectArray'];
+        $this->nestedArray = $values['nestedArray'];
+        $this->datesArray = $values['datesArray'];
+        $this->nullableProperty = $values['nullableProperty'] ?? null;
+    }
+}
+
+class TestTypeTest extends TestCase
+{
+    /**
+     * Test serialization and deserialization of all types in TestType
+     */
+    public function testSerializationAndDeserialization(): void
+    {
+        // Create test data
+        $data = [
+            'nested_type' => ['nested_property' => '1995-07-20'],
+            'simple_property' => 'Test String',
+            // 'nullable_property' is omitted to test null serialization
+            'date_property' => '2023-01-01',
+            'datetime_property' => '2023-01-01T12:34:56+00:00',
+            'string_array' => ['one', 'two', 'three'],
+            'map_property' => ['key1' => 1, 'key2' => 2],
+            'object_array' => [
+                1 => ['nested_property' =>  '2021-07-20'],
+                2 => null, // Testing nullable objects in array
+            ],
+            'nested_array' => [
+                1 => [1 => 'value1', 2 => null], // Testing nullable strings in nested array
+                2 => [3 => 'value3', 4 => 'value4']
+            ],
+            'dates_array' => ['2023-01-01', null, '2023-03-01'] // Testing nullable dates in array
+        ];
+
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+
+        $object = TestType::fromJson($json);
+
+        $serializedJson = $object->toJson();
+
+        $this->assertJsonStringEqualsJsonString($json, $serializedJson, 'The serialized JSON does not match the original JSON.');
+
+        // Check that nullable property is null and not included in JSON
+        $this->assertNull($object->nullableProperty, 'Nullable property should be null.');
+        // @phpstan-ignore-next-line
+        $this->assertFalse(array_key_exists('nullable_property', json_decode($serializedJson, true)), 'Nullable property should be omitted from JSON.');
+
+        // Check date properties
+        $this->assertInstanceOf(DateTime::class, $object->dateProperty, 'date_property should be a DateTime instance.');
+        $this->assertEquals('2023-01-01', $object->dateProperty->format('Y-m-d'), 'date_property should have the correct date.');
+
+        $this->assertInstanceOf(DateTime::class, $object->datetimeProperty, 'datetime_property should be a DateTime instance.');
+        $this->assertEquals('2023-01-01 12:34:56', $object->datetimeProperty->format('Y-m-d H:i:s'), 'datetime_property should have the correct datetime.');
+
+        // Check scalar arrays
+        $this->assertEquals(['one', 'two', 'three'], $object->stringArray, 'string_array should match the original data.');
+        $this->assertEquals(['key1' => 1, 'key2' => 2], $object->mapProperty, 'map_property should match the original data.');
+
+        // Check object array with nullable elements
+        $this->assertInstanceOf(TestNestedType1::class, $object->objectArray[1], 'object_array[1] should be an instance of TestNestedType1.');
+        $this->assertEquals('2021-07-20', $object->objectArray[1]->nestedProperty->format('Y-m-d'), 'object_array[1]->nestedProperty should match the original data.');
+        $this->assertNull($object->objectArray[2], 'object_array[2] should be null.');
+
+        // Check nested array with nullable strings
+        $this->assertEquals('value1', $object->nestedArray[1][1], 'nested_array[1][1] should match the original data.');
+        $this->assertNull($object->nestedArray[1][2], 'nested_array[1][2] should be null.');
+        $this->assertEquals('value3', $object->nestedArray[2][3], 'nested_array[2][3] should match the original data.');
+        $this->assertEquals('value4', $object->nestedArray[2][4], 'nested_array[2][4] should match the original data.');
+
+        // Check dates array with nullable DateTime objects
+        $this->assertInstanceOf(DateTime::class, $object->datesArray[0], 'dates_array[0] should be a DateTime instance.');
+        $this->assertEquals('2023-01-01', $object->datesArray[0]->format('Y-m-d'), 'dates_array[0] should have the correct date.');
+        $this->assertNull($object->datesArray[1], 'dates_array[1] should be null.');
+        $this->assertInstanceOf(DateTime::class, $object->datesArray[2], 'dates_array[2] should be a DateTime instance.');
+        $this->assertEquals('2023-03-01', $object->datesArray[2]->format('Y-m-d'), 'dates_array[2] should have the correct date.');
+    }
+}
diff --git a/seed/php-model/server-sent-events/tests/Seed/Core/UnionArrayTypeTest.php b/seed/php-model/server-sent-events/tests/Seed/Core/UnionArrayTypeTest.php
new file mode 100644
index 00000000000..8d0998f4b7e
--- /dev/null
+++ b/seed/php-model/server-sent-events/tests/Seed/Core/UnionArrayTypeTest.php
@@ -0,0 +1,56 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+use Seed\Core\ArrayType;
+use Seed\Core\Union;
+
+class UnionArrayType extends SerializableType
+{
+    /**
+     * @var array<int, string|int|null> $mixedArray
+     */
+    #[ArrayType(['integer' => new Union('string', 'integer', 'null')])]
+    #[JsonProperty('mixed_array')]
+    public array $mixedArray;
+
+    /**
+     * @param array{
+     *   mixedArray: array<int, string|int|null>,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->mixedArray = $values['mixedArray'];
+    }
+}
+
+class UnionArrayTypeTest extends TestCase
+{
+    public function testUnionTypesInArrays(): void
+    {
+        $data = [
+            'mixed_array' => [
+                1 => 'one',
+                2 => 2,
+                3 => null
+            ]
+        ];
+
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+
+        $object = UnionArrayType::fromJson($json);
+
+        $this->assertEquals('one', $object->mixedArray[1], 'mixed_array[1] should be "one".');
+        $this->assertEquals(2, $object->mixedArray[2], 'mixed_array[2] should be 2.');
+        $this->assertNull($object->mixedArray[3], 'mixed_array[3] should be null.');
+
+        $serializedJson = $object->toJson();
+
+        $this->assertJsonStringEqualsJsonString($json, $serializedJson, 'Serialized JSON does not match original JSON for mixed_array.');
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/.github/workflows/ci.yml b/seed/php-sdk/server-sent-events/.github/workflows/ci.yml
new file mode 100644
index 00000000000..258bf33a19f
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/.github/workflows/ci.yml
@@ -0,0 +1,48 @@
+name: ci
+
+on: [push]
+
+jobs:
+  compile:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: "8.1"
+
+      - name: Install tools
+        run: |
+          composer install
+
+      - name: Build
+        run: |
+          composer build
+
+      - name: Analyze
+        run: |
+          composer analyze
+
+  unit-tests:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: "8.1"
+
+      - name: Install tools
+        run: |
+          composer install
+
+      - name: Run Tests
+        run: |
+          composer test
\ No newline at end of file
diff --git a/seed/php-sdk/server-sent-events/.gitignore b/seed/php-sdk/server-sent-events/.gitignore
new file mode 100644
index 00000000000..f38efc46ade
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/.gitignore
@@ -0,0 +1,4 @@
+.php-cs-fixer.cache
+.phpunit.result.cache
+composer.lock
+vendor/
\ No newline at end of file
diff --git a/seed/php-sdk/server-sent-events/.mock/definition/api.yml b/seed/php-sdk/server-sent-events/.mock/definition/api.yml
new file mode 100644
index 00000000000..80e84c41785
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/.mock/definition/api.yml
@@ -0,0 +1 @@
+name: server-sent-events
diff --git a/seed/php-sdk/server-sent-events/.mock/definition/completions.yml b/seed/php-sdk/server-sent-events/.mock/definition/completions.yml
new file mode 100644
index 00000000000..d1748fad19e
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/.mock/definition/completions.yml
@@ -0,0 +1,22 @@
+types:
+  StreamedCompletion:
+    properties:
+      delta: string
+      tokens: optional<integer>
+
+service:
+  auth: false
+  base-path: ""
+  endpoints:
+    stream:
+      method: POST
+      path: /stream
+      request:
+        name: StreamCompletionRequest
+        body:
+          properties:
+            query: string
+      response-stream:
+        type: StreamedCompletion
+        format: sse
+        terminator: "[[DONE]]"
diff --git a/seed/php-sdk/server-sent-events/.mock/fern.config.json b/seed/php-sdk/server-sent-events/.mock/fern.config.json
new file mode 100644
index 00000000000..4c8e54ac313
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/.mock/fern.config.json
@@ -0,0 +1 @@
+{"organization": "fern-test", "version": "*"}
\ No newline at end of file
diff --git a/seed/php-sdk/server-sent-events/.mock/generators.yml b/seed/php-sdk/server-sent-events/.mock/generators.yml
new file mode 100644
index 00000000000..0967ef424bc
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/.mock/generators.yml
@@ -0,0 +1 @@
+{}
diff --git a/seed/php-sdk/server-sent-events/composer.json b/seed/php-sdk/server-sent-events/composer.json
new file mode 100644
index 00000000000..7f5821806d4
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/composer.json
@@ -0,0 +1,40 @@
+
+{
+  "name": "seed/seed",
+  "version": "0.0.1",
+  "description": "Seed PHP Library",
+  "keywords": [
+    "seed",
+    "api",
+    "sdk"
+  ],
+  "license": [],
+  "require": {
+    "php": "^8.1",
+    "ext-json": "*",
+    "guzzlehttp/guzzle": "^7.9"
+  },
+  "require-dev": {
+    "phpunit/phpunit": "^9.0",
+    "friendsofphp/php-cs-fixer": "3.5.0",
+    "phpstan/phpstan": "^1.12"
+  },
+  "autoload": {
+    "psr-4": {
+      "Seed\\": "src/"
+    }
+  },
+  "autoload-dev": {
+    "psr-4": {
+      "\\Seed\\Tests\\": "tests/"
+    }
+  },
+  "scripts": {
+    "build": [
+      "@php -l src",
+      "@php -l tests"
+    ],
+    "test": "phpunit",
+    "analyze": "phpstan analyze src"
+  }
+}
diff --git a/seed/php-sdk/server-sent-events/phpstan.neon b/seed/php-sdk/server-sent-events/phpstan.neon
new file mode 100644
index 00000000000..29a11a92a19
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/phpstan.neon
@@ -0,0 +1,5 @@
+parameters:
+    level: max
+    paths:
+        - src
+        - tests
\ No newline at end of file
diff --git a/seed/php-sdk/server-sent-events/phpunit.xml b/seed/php-sdk/server-sent-events/phpunit.xml
new file mode 100644
index 00000000000..54630a51163
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/phpunit.xml
@@ -0,0 +1,7 @@
+<phpunit bootstrap="vendor/autoload.php">
+    <testsuites>
+        <testsuite name="Test Suite">
+            <directory suffix="Test.php">tests</directory>
+        </testsuite>
+    </testsuites>
+</phpunit>
\ No newline at end of file
diff --git a/seed/php-sdk/server-sent-events/snippet-templates.json b/seed/php-sdk/server-sent-events/snippet-templates.json
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/seed/php-sdk/server-sent-events/snippet.json b/seed/php-sdk/server-sent-events/snippet.json
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/seed/php-sdk/server-sent-events/src/Completions/CompletionsClient.php b/seed/php-sdk/server-sent-events/src/Completions/CompletionsClient.php
new file mode 100644
index 00000000000..2b145a52d09
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Completions/CompletionsClient.php
@@ -0,0 +1,58 @@
+<?php
+
+namespace Seed\Completions;
+
+use Seed\Core\RawClient;
+use Seed\Completions\Requests\StreamCompletionRequest;
+use Seed\Exceptions\SeedException;
+use Seed\Exceptions\SeedApiException;
+use Seed\Core\JsonApiRequest;
+use Seed\Core\HttpMethod;
+use Psr\Http\Client\ClientExceptionInterface;
+
+class CompletionsClient
+{
+    /**
+     * @var RawClient $client
+     */
+    private RawClient $client;
+
+    /**
+     * @param RawClient $client
+     */
+    public function __construct(
+        RawClient $client,
+    ) {
+        $this->client = $client;
+    }
+
+    /**
+     * @param StreamCompletionRequest $request
+     * @param ?array{
+     *   baseUrl?: string,
+     * } $options
+     * @throws SeedException
+     * @throws SeedApiException
+     */
+    public function stream(StreamCompletionRequest $request, ?array $options = null): void
+    {
+        try {
+            $response = $this->client->sendRequest(
+                new JsonApiRequest(
+                    baseUrl: $options['baseUrl'] ?? $this->client->options['baseUrl'] ?? '',
+                    path: "stream",
+                    method: HttpMethod::POST,
+                    body: $request,
+                ),
+            );
+            $statusCode = $response->getStatusCode();
+        } catch (ClientExceptionInterface $e) {
+            throw new SeedException(message: $e->getMessage(), previous: $e);
+        }
+        throw new SeedApiException(
+            message: 'API request failed',
+            statusCode: $statusCode,
+            body: $response->getBody()->getContents(),
+        );
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/src/Completions/Requests/StreamCompletionRequest.php b/seed/php-sdk/server-sent-events/src/Completions/Requests/StreamCompletionRequest.php
new file mode 100644
index 00000000000..2023705caff
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Completions/Requests/StreamCompletionRequest.php
@@ -0,0 +1,26 @@
+<?php
+
+namespace Seed\Completions\Requests;
+
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+
+class StreamCompletionRequest extends SerializableType
+{
+    /**
+     * @var string $query
+     */
+    #[JsonProperty('query')]
+    public string $query;
+
+    /**
+     * @param array{
+     *   query: string,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->query = $values['query'];
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/src/Completions/Types/StreamedCompletion.php b/seed/php-sdk/server-sent-events/src/Completions/Types/StreamedCompletion.php
new file mode 100644
index 00000000000..0573b87281c
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Completions/Types/StreamedCompletion.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace Seed\Completions\Types;
+
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+
+class StreamedCompletion extends SerializableType
+{
+    /**
+     * @var string $delta
+     */
+    #[JsonProperty('delta')]
+    public string $delta;
+
+    /**
+     * @var ?int $tokens
+     */
+    #[JsonProperty('tokens')]
+    public ?int $tokens;
+
+    /**
+     * @param array{
+     *   delta: string,
+     *   tokens?: ?int,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->delta = $values['delta'];
+        $this->tokens = $values['tokens'] ?? null;
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/src/Core/ArrayType.php b/seed/php-sdk/server-sent-events/src/Core/ArrayType.php
new file mode 100644
index 00000000000..b2ed8bf12b2
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Core/ArrayType.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Seed\Core;
+
+use Attribute;
+
+#[Attribute(Attribute::TARGET_PROPERTY)]
+class ArrayType
+{
+    /**
+     * @param mixed[] $type Array in the form ['keyType' => 'valueType'] for maps, or ['valueType'] for lists
+     */
+    public function __construct(public array $type)
+    {
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/src/Core/BaseApiRequest.php b/seed/php-sdk/server-sent-events/src/Core/BaseApiRequest.php
new file mode 100644
index 00000000000..2ace034ec90
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Core/BaseApiRequest.php
@@ -0,0 +1,22 @@
+<?php
+
+namespace Seed\Core;
+
+abstract class BaseApiRequest
+{
+    /**
+     * @param string $baseUrl The base URL for the request
+     * @param string $path The path for the request
+     * @param HttpMethod $method The HTTP method for the request
+     * @param array<string, string> $headers Additional headers for the request (optional)
+     * @param array<string, mixed> $query Query parameters for the request (optional)
+     */
+    public function __construct(
+        public readonly string      $baseUrl,
+        public readonly string      $path,
+        public readonly HttpMethod  $method,
+        public readonly array       $headers = [],
+        public readonly array       $query = [],
+    ) {
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/src/Core/Constant.php b/seed/php-sdk/server-sent-events/src/Core/Constant.php
new file mode 100644
index 00000000000..abbac7f6649
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Core/Constant.php
@@ -0,0 +1,12 @@
+<?php
+
+namespace Seed\Core;
+
+use DateTimeInterface;
+
+class Constant
+{
+    public const DateFormat = 'Y-m-d';
+    public const DateDeserializationFormat = "!" . self::DateFormat;
+    public const DateTimeFormat = DateTimeInterface::RFC3339;
+}
diff --git a/seed/php-sdk/server-sent-events/src/Core/DateType.php b/seed/php-sdk/server-sent-events/src/Core/DateType.php
new file mode 100644
index 00000000000..dcf05bb2710
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Core/DateType.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Seed\Core;
+
+use Attribute;
+
+#[Attribute(Attribute::TARGET_PROPERTY)]
+class DateType
+{
+    public const TYPE_DATE = 'date';
+    public const TYPE_DATETIME = 'datetime';
+
+    public function __construct(public string $type)
+    {
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/src/Core/HttpMethod.php b/seed/php-sdk/server-sent-events/src/Core/HttpMethod.php
new file mode 100644
index 00000000000..22cd7d22cd5
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Core/HttpMethod.php
@@ -0,0 +1,12 @@
+<?php
+
+namespace Seed\Core;
+
+enum HttpMethod
+{
+    case GET;
+    case POST;
+    case PUT;
+    case PATCH;
+    case DELETE;
+}
diff --git a/seed/php-sdk/server-sent-events/src/Core/JsonApiRequest.php b/seed/php-sdk/server-sent-events/src/Core/JsonApiRequest.php
new file mode 100644
index 00000000000..4c0e7dd01e8
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Core/JsonApiRequest.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace Seed\Core;
+
+class JsonApiRequest extends BaseApiRequest
+{
+    /**
+     * @param string $baseUrl The base URL for the request
+     * @param string $path The path for the request
+     * @param HttpMethod $method The HTTP method for the request
+     * @param array<string, string> $headers Additional headers for the request (optional)
+     * @param array<string, mixed> $query Query parameters for the request (optional)
+     * @param mixed|null $body The JSON request body (optional)
+     */
+    public function __construct(
+        string $baseUrl,
+        string $path,
+        HttpMethod $method,
+        array $headers = [],
+        array $query = [],
+        public readonly mixed $body = null
+    ) {
+        parent::__construct($baseUrl, $path, $method, $headers, $query);
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/src/Core/JsonDecoder.php b/seed/php-sdk/server-sent-events/src/Core/JsonDecoder.php
new file mode 100644
index 00000000000..34651d0b9eb
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Core/JsonDecoder.php
@@ -0,0 +1,147 @@
+<?php
+
+namespace Seed\Core;
+
+use DateTime;
+use Exception;
+use JsonException;
+
+class JsonDecoder
+{
+    /**
+     * Decodes a JSON string and returns a string.
+     *
+     * @param string $json The JSON string to decode.
+     * @return string The decoded string.
+     * @throws JsonException If the decoded value is not a string.
+     */
+    public static function decodeString(string $json): string
+    {
+        $decoded = self::decode($json);
+        if (!is_string($decoded)) {
+            throw new JsonException("Unexpected non-string json value: " . $json);
+        }
+        return $decoded;
+    }
+
+    /**
+     * Decodes a JSON string and returns a boolean.
+     *
+     * @param string $json The JSON string to decode.
+     * @return bool The decoded boolean.
+     * @throws JsonException If the decoded value is not a boolean.
+     */
+    public static function decodeBool(string $json): bool
+    {
+        $decoded = self::decode($json);
+        if (!is_bool($decoded)) {
+            throw new JsonException("Unexpected non-boolean json value: " . $json);
+        }
+        return $decoded;
+    }
+
+    /**
+     * Decodes a JSON string and returns a DateTime object.
+     *
+     * @param string $json The JSON string to decode.
+     * @return DateTime The decoded DateTime object.
+     * @throws JsonException If the decoded value is not a valid datetime string.
+     */
+    public static function decodeDateTime(string $json): DateTime
+    {
+        $decoded = self::decode($json);
+        if (!is_string($decoded)) {
+            throw new JsonException("Unexpected non-string json value for datetime: " . $json);
+        }
+        return JsonDeserializer::deserializeDateTime($decoded);
+    }
+
+    /**
+     * Decodes a JSON string and returns a DateTime object representing a date.
+     *
+     * @param string $json The JSON string to decode.
+     * @return DateTime The decoded DateTime object.
+     * @throws JsonException If the decoded value is not a valid date string.
+     */
+    public static function decodeDate(string $json): DateTime
+    {
+        $decoded = self::decode($json);
+        if (!is_string($decoded)) {
+            throw new JsonException("Unexpected non-string json value for date: " . $json);
+        }
+        return JsonDeserializer::deserializeDate($decoded);
+    }
+
+    /**
+     * Decodes a JSON string and returns a float.
+     *
+     * @param string $json The JSON string to decode.
+     * @return float The decoded float.
+     * @throws JsonException If the decoded value is not a float.
+     */
+    public static function decodeFloat(string $json): float
+    {
+        $decoded = self::decode($json);
+        if (!is_float($decoded)) {
+            throw new JsonException("Unexpected non-float json value: " . $json);
+        }
+        return $decoded;
+    }
+
+    /**
+     * Decodes a JSON string and returns an integer.
+     *
+     * @param string $json The JSON string to decode.
+     * @return int The decoded integer.
+     * @throws JsonException If the decoded value is not an integer.
+     */
+    public static function decodeInt(string $json): int
+    {
+        $decoded = self::decode($json);
+        if (!is_int($decoded)) {
+            throw new JsonException("Unexpected non-integer json value: " . $json);
+        }
+        return $decoded;
+    }
+
+    /**
+     * Decodes a JSON string into an array and deserializes it based on the provided type.
+     *
+     * @param string $json The JSON string to decode.
+     * @param mixed[]|array<string, mixed> $type The type definition for deserialization.
+     * @return mixed[]|array<string, mixed> The deserialized array.
+     * @throws JsonException If the decoded value is not an array.
+     */
+    public static function decodeArray(string $json, array $type): array
+    {
+        $decoded = self::decode($json);
+        if (!is_array($decoded)) {
+            throw new JsonException("Unexpected non-array json value: " . $json);
+        }
+        return JsonDeserializer::deserializeArray($decoded, $type);
+    }
+
+    /**
+     * Decodes a JSON string and returns a mixed.
+     *
+     * @param string $json The JSON string to decode.
+     * @return mixed The decoded mixed.
+     * @throws JsonException If the decoded value is not an mixed.
+     */
+    public static function decodeMixed(string $json): mixed
+    {
+        return self::decode($json);
+    }
+
+    /**
+     * Decodes a JSON string into a PHP value.
+     *
+     * @param string $json The JSON string to decode.
+     * @return mixed The decoded value.
+     * @throws JsonException If an error occurs during JSON decoding.
+     */
+    public static function decode(string $json): mixed
+    {
+        return json_decode($json, associative: true, flags: JSON_THROW_ON_ERROR);
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/src/Core/JsonDeserializer.php b/seed/php-sdk/server-sent-events/src/Core/JsonDeserializer.php
new file mode 100644
index 00000000000..4c9998886ee
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Core/JsonDeserializer.php
@@ -0,0 +1,187 @@
+<?php
+
+namespace Seed\Core;
+
+use DateTime;
+use Exception;
+use JsonException;
+
+class JsonDeserializer
+{
+    /**
+     * Deserializes a string into a DateTime object.
+     *
+     * @param string $datetime The date/time string to deserialize.
+     * @return DateTime
+     * @throws JsonException If the DateTime creation fails.
+     */
+    public static function deserializeDateTime(string $datetime): DateTime
+    {
+        try {
+            return new DateTime($datetime);
+        } catch (Exception $e) {
+            throw new JsonException("Failed to create DateTime from string: $datetime", previous: $e);
+        }
+    }
+
+    /**
+     * Deserializes a string into a DateTime object using a specific format.
+     *
+     * @param string $date The date string to deserialize.
+     * @return DateTime
+     * @throws JsonException If the date creation fails.
+     */
+    public static function deserializeDate(string $date): DateTime
+    {
+        $dateTime = DateTime::createFromFormat(Constant::DateDeserializationFormat, $date);
+        if ($dateTime === false) {
+            throw new JsonException("Failed to create date from string: $date");
+        }
+        return $dateTime;
+    }
+
+    /**
+     * Deserializes an array based on type annotations (either a list or a map).
+     *
+     * @param mixed[]|array<string, mixed> $data The array to be deserialized.
+     * @param mixed[]|array<string, mixed> $type The type definition from the annotation.
+     * @return mixed[]|array<string, mixed> The deserialized array.
+     * @throws JsonException If deserialization fails.
+     */
+    public static function deserializeArray(array $data, array $type): array
+    {
+        return Utils::isMapType($type)
+            ? self::deserializeMap($data, $type)
+            : self::deserializeList($data, $type);
+    }
+
+    /**
+     * Deserializes a value based on its type definition.
+     *
+     * @param mixed $data The data to deserialize.
+     * @param mixed $type The type definition.
+     * @return mixed The deserialized value.
+     * @throws JsonException If deserialization fails.
+     */
+    private static function deserializeValue(mixed $data, mixed $type): mixed
+    {
+        if ($type instanceof Union) {
+            foreach ($type->types as $unionType) {
+                try {
+                    return self::deserializeSingleValue($data, $unionType);
+                } catch (Exception) {
+                    continue;
+                }
+            }
+            $readableType = Utils::getReadableType($data);
+            throw new JsonException(
+                "Cannot deserialize value of type $readableType with any of the union types: " . $type
+            );
+        }
+        if (is_array($type)) {
+            return self::deserializeArray((array)$data, $type);
+        }
+
+        if (gettype($type) != "string") {
+            throw new JsonException("Unexpected non-string type.");
+        }
+        return self::deserializeSingleValue($data, $type);
+    }
+
+    /**
+     * Deserializes a single value based on its expected type.
+     *
+     * @param mixed $data The data to deserialize.
+     * @param string $type The expected type.
+     * @return mixed The deserialized value.
+     * @throws JsonException If deserialization fails.
+     */
+    private static function deserializeSingleValue(mixed $data, string $type): mixed
+    {
+        if ($type === 'null' && $data === null) {
+            return null;
+        }
+
+        if ($type === 'date' && is_string($data)) {
+            return self::deserializeDate($data);
+        }
+
+        if ($type === 'datetime' && is_string($data)) {
+            return self::deserializeDateTime($data);
+        }
+
+        if ($type === 'mixed') {
+            return $data;
+        }
+
+        if (class_exists($type) && is_array($data)) {
+            return self::deserializeObject($data, $type);
+        }
+
+        // Handle floats as a special case since gettype($data) returns "double" for float values in PHP, and because
+        // floats make come through from json_decoded as integers
+        if ($type === 'float' && (is_numeric($data))) {
+            return (float) $data;
+        }
+
+        if (gettype($data) === $type) {
+            return $data;
+        }
+
+        throw new JsonException("Unable to deserialize value of type '" . gettype($data) . "' as '$type'.");
+    }
+
+    /**
+     * Deserializes an array into an object of the given type.
+     *
+     * @param array<string, mixed> $data The data to deserialize.
+     * @param string $type The class name of the object to deserialize into.
+     *
+     * @return object The deserialized object.
+     *
+     * @throws JsonException If the type does not implement SerializableType.
+     */
+    public static function deserializeObject(array $data, string $type): object
+    {
+        if (!is_subclass_of($type, SerializableType::class)) {
+            throw new JsonException("$type is not a subclass of SerializableType.");
+        }
+        return $type::jsonDeserialize($data);
+    }
+
+    /**
+     * Deserializes a map (associative array) with defined key and value types.
+     *
+     * @param array<string, mixed> $data The associative array to deserialize.
+     * @param array<string, mixed> $type The type definition for the map.
+     * @return array<string, mixed> The deserialized map.
+     * @throws JsonException If deserialization fails.
+     */
+    private static function deserializeMap(array $data, array $type): array
+    {
+        $keyType = array_key_first($type);
+        $valueType = $type[$keyType];
+        $result = [];
+
+        foreach ($data as $key => $item) {
+            $key = Utils::castKey($key, (string)$keyType);
+            $result[$key] = self::deserializeValue($item, $valueType);
+        }
+
+        return $result;
+    }
+
+    /**
+     * Deserializes a list (indexed array) with a defined value type.
+     *
+     * @param array<int, mixed> $data The list to deserialize.
+     * @param array<int, mixed> $type The type definition for the list.
+     * @return array<int, mixed> The deserialized list.
+     * @throws JsonException If deserialization fails.
+     */
+    private static function deserializeList(array $data, array $type): array
+    {
+        $valueType = $type[0];
+        return array_map(fn ($item) => self::deserializeValue($item, $valueType), $data);
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/src/Core/JsonEncoder.php b/seed/php-sdk/server-sent-events/src/Core/JsonEncoder.php
new file mode 100644
index 00000000000..ba5191a8068
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Core/JsonEncoder.php
@@ -0,0 +1,20 @@
+<?php
+
+namespace Seed\Core;
+
+use JsonException;
+
+class JsonEncoder
+{
+    /**
+     * Encodes a PHP value into JSON string.
+     *
+     * @param mixed $value The PHP value to encode.
+     * @return string The encoded string.
+     * @throws JsonException
+     */
+    public static function encode(mixed $value): string
+    {
+        return json_encode($value, JSON_THROW_ON_ERROR);
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/src/Core/JsonProperty.php b/seed/php-sdk/server-sent-events/src/Core/JsonProperty.php
new file mode 100644
index 00000000000..06a436fff9b
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Core/JsonProperty.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace Seed\Core;
+
+use Attribute;
+
+#[Attribute(Attribute::TARGET_PROPERTY)]
+class JsonProperty
+{
+    public function __construct(public string $name)
+    {
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/src/Core/JsonSerializer.php b/seed/php-sdk/server-sent-events/src/Core/JsonSerializer.php
new file mode 100644
index 00000000000..eae0c087441
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Core/JsonSerializer.php
@@ -0,0 +1,173 @@
+<?php
+
+namespace Seed\Core;
+
+use DateTime;
+use Exception;
+use JsonException;
+use JsonSerializable;
+
+class JsonSerializer
+{
+    /**
+     * Serializes a DateTime object into a string using the date format.
+     *
+     * @param DateTime $date The DateTime object to serialize.
+     * @return string The serialized date string.
+     */
+    public static function serializeDate(DateTime $date): string
+    {
+        return $date->format(Constant::DateFormat);
+    }
+
+    /**
+     * Serializes a DateTime object into a string using the date-time format.
+     *
+     * @param DateTime $date The DateTime object to serialize.
+     * @return string The serialized date-time string.
+     */
+    public static function serializeDateTime(DateTime $date): string
+    {
+        return $date->format(Constant::DateTimeFormat);
+    }
+
+    /**
+     * Serializes an array based on type annotations (either a list or map).
+     *
+     * @param mixed[]|array<string, mixed> $data The array to be serialized.
+     * @param mixed[]|array<string, mixed> $type The type definition from the annotation.
+     * @return mixed[]|array<string, mixed> The serialized array.
+     * @throws JsonException If serialization fails.
+     */
+    public static function serializeArray(array $data, array $type): array
+    {
+        return Utils::isMapType($type)
+            ? self::serializeMap($data, $type)
+            : self::serializeList($data, $type);
+    }
+
+    /**
+     * Serializes a value based on its type definition.
+     *
+     * @param mixed $data The value to serialize.
+     * @param mixed $type The type definition.
+     * @return mixed The serialized value.
+     * @throws JsonException If serialization fails.
+     */
+    private static function serializeValue(mixed $data, mixed $type): mixed
+    {
+        if ($type instanceof Union) {
+            foreach ($type->types as $unionType) {
+                try {
+                    return self::serializeSingleValue($data, $unionType);
+                } catch (Exception) {
+                    continue;
+                }
+            }
+            throw new JsonException("Cannot serialize value with any of the union types.");
+        }
+
+        if (is_array($type)) {
+            return self::serializeArray((array)$data, $type);
+        }
+
+        if (gettype($type) != "string") {
+            throw new JsonException("Unexpected non-string type.");
+        }
+
+        return self::serializeSingleValue($data, $type);
+    }
+
+    /**
+     * Serializes a single value based on its type.
+     *
+     * @param mixed $data The value to serialize.
+     * @param string $type The expected type.
+     * @return mixed The serialized value.
+     * @throws JsonException If serialization fails.
+     */
+    private static function serializeSingleValue(mixed $data, string $type): mixed
+    {
+        if ($type === 'null' && $data === null) {
+            return null;
+        }
+
+        if (($type === 'date' || $type === 'datetime') && $data instanceof DateTime) {
+            return $type === 'date' ? self::serializeDate($data) : self::serializeDateTime($data);
+        }
+
+        if ($type === 'mixed') {
+            return $data;
+        }
+
+        if (class_exists($type) && $data instanceof $type) {
+            return self::serializeObject($data);
+        }
+
+        // Handle floats as a special case since gettype($data) returns "double" for float values in PHP.
+        if ($type === 'float' && is_float($data)) {
+            return $data;
+        }
+
+        if (gettype($data) === $type) {
+            return $data;
+        }
+
+        throw new JsonException("Unable to serialize value of type '" . gettype($data) . "' as '$type'.");
+    }
+
+    /**
+     * Serializes an object to a JSON-serializable format.
+     *
+     * @param object $data The object to serialize.
+     * @return mixed The serialized data.
+     * @throws JsonException If the object does not implement JsonSerializable.
+     */
+    public static function serializeObject(object $data): mixed
+    {
+        if (!is_subclass_of($data, JsonSerializable::class)) {
+            $type = get_class($data);
+            throw new JsonException("Class $type must implement JsonSerializable.");
+        }
+        return $data->jsonSerialize();
+    }
+
+    /**
+     * Serializes a map (associative array) with defined key and value types.
+     *
+     * @param array<string, mixed> $data The associative array to serialize.
+     * @param array<string, mixed> $type The type definition for the map.
+     * @return array<string, mixed> The serialized map.
+     * @throws JsonException If serialization fails.
+     */
+    private static function serializeMap(array $data, array $type): array
+    {
+        $keyType = array_key_first($type);
+        if ($keyType === null) {
+            throw new JsonException("Unexpected no key in ArrayType.");
+        }
+        $valueType = $type[$keyType];
+        $result = [];
+
+        foreach ($data as $key => $item) {
+            $key = Utils::castKey($key, $keyType);
+            $result[$key] = self::serializeValue($item, $valueType);
+        }
+
+        return $result;
+    }
+
+    /**
+     * Serializes a list (indexed array) where only the value type is defined.
+     *
+     * @param array<int, mixed> $data The list to serialize.
+     * @param array<int, mixed> $type The type definition for the list.
+     * @return array<int, mixed> The serialized list.
+     * @throws JsonException If serialization fails.
+     */
+    private static function serializeList(array $data, array $type): array
+    {
+        $valueType = $type[0];
+        return array_map(fn ($item) => self::serializeValue($item, $valueType), $data);
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/src/Core/RawClient.php b/seed/php-sdk/server-sent-events/src/Core/RawClient.php
new file mode 100644
index 00000000000..1c0e42bf650
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Core/RawClient.php
@@ -0,0 +1,138 @@
+<?php
+
+namespace Seed\Core;
+
+use GuzzleHttp\Client;
+use GuzzleHttp\ClientInterface;
+use GuzzleHttp\Psr7\Request;
+use GuzzleHttp\Psr7\Utils;
+use InvalidArgumentException;
+use Psr\Http\Client\ClientExceptionInterface;
+use Psr\Http\Message\ResponseInterface;
+use Psr\Http\Message\StreamInterface;
+
+class RawClient
+{
+    /**
+     * @var ClientInterface $client
+     */
+    private ClientInterface $client;
+
+    /**
+     * @var array<string, string> $headers
+     */
+    private array $headers;
+
+    /**
+     * @param ?array{
+     *   baseUrl?: string,
+     *   client?: ClientInterface,
+     *   headers?: array<string, string>,
+     * } $options
+     */
+    public function __construct(
+        public readonly ?array $options = null,
+    ) {
+        $this->client = $this->options['client'] ?? new Client();
+        $this->headers = $this->options['headers'] ?? [];
+    }
+
+    /**
+     * @throws ClientExceptionInterface
+     */
+    public function sendRequest(
+        BaseApiRequest $request,
+    ): ResponseInterface {
+        $httpRequest = $this->buildRequest($request);
+        return $this->client->send($httpRequest);
+    }
+
+    private function buildRequest(
+        BaseApiRequest $request
+    ): Request {
+        $url = $this->buildUrl($request);
+        $headers = $this->encodeHeaders($request);
+        $body = $this->encodeRequestBody($request);
+        return new Request(
+            $request->method->name,
+            $url,
+            $headers,
+            $body,
+        );
+    }
+
+    /**
+     * @return array<string, string>
+     */
+    private function encodeHeaders(
+        BaseApiRequest $request
+    ): array {
+        return match (get_class($request)) {
+            JsonApiRequest::class => array_merge(
+                ["Content-Type" => "application/json"],
+                $this->headers,
+                $request->headers
+            ),
+            default => throw new InvalidArgumentException('Unsupported request type: ' . get_class($request)),
+        };
+    }
+
+    private function encodeRequestBody(
+        BaseApiRequest $request
+    ): ?StreamInterface {
+        return match (get_class($request)) {
+            JsonApiRequest::class => $request->body != null ? Utils::streamFor(json_encode($request->body)) : null,
+            default => throw new InvalidArgumentException('Unsupported request type: '.get_class($request)),
+        };
+    }
+
+    private function buildUrl(
+        BaseApiRequest $request
+    ): string {
+        $baseUrl = $request->baseUrl;
+        $trimmedBaseUrl = rtrim($baseUrl, '/');
+        $trimmedBasePath = ltrim($request->path, '/');
+        $url = "{$trimmedBaseUrl}/{$trimmedBasePath}";
+
+        if (!empty($request->query)) {
+            $url .= '?' . $this->encodeQuery($request->query);
+        }
+
+        return $url;
+    }
+
+    /**
+     * @param array<string, mixed> $query
+     */
+    private function encodeQuery(
+        array $query
+    ): string {
+        $parts = [];
+        foreach ($query as $key => $value) {
+            if (is_array($value)) {
+                foreach ($value as $item) {
+                    $parts[] = urlencode($key).'='.$this->encodeQueryValue($item);
+                }
+            } else {
+                $parts[] = urlencode($key).'='.$this->encodeQueryValue($value);
+            }
+        }
+        return implode('&', $parts);
+    }
+
+    private function encodeQueryValue(
+        mixed $value
+    ): string {
+        if (is_string($value)) {
+            return urlencode($value);
+        }
+        if (is_scalar($value)) {
+            return urlencode((string)$value);
+        }
+        if (is_null($value)) {
+            return 'null';
+        }
+        // Unreachable, but included for a best effort.
+        return urlencode(strval(json_encode($value)));
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/src/Core/SerializableType.php b/seed/php-sdk/server-sent-events/src/Core/SerializableType.php
new file mode 100644
index 00000000000..ecb6c6abc19
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Core/SerializableType.php
@@ -0,0 +1,165 @@
+<?php
+
+namespace Seed\Core;
+
+use DateTime;
+use Exception;
+use JsonException;
+use ReflectionNamedType;
+use ReflectionProperty;
+
+/**
+ * Provides generic serialization and deserialization methods.
+ */
+abstract class SerializableType implements \JsonSerializable
+{
+    /**
+     * Serializes the object to a JSON string.
+     *
+     * @return string JSON-encoded string representation of the object.
+     * @throws Exception If encoding fails.
+     */
+    public function toJson(): string
+    {
+        $serializedObject = $this->jsonSerialize();
+        $encoded = JsonEncoder::encode($serializedObject);
+        if (!$encoded) {
+            throw new Exception("Could not encode type");
+        }
+        return $encoded;
+    }
+
+    /**
+     * Serializes the object to an array.
+     *
+     * @return mixed[] Array representation of the object.
+     * @throws JsonException If serialization fails.
+     */
+    public function jsonSerialize(): array
+    {
+        $result = [];
+        $reflectionClass = new \ReflectionClass($this);
+
+        foreach ($reflectionClass->getProperties() as $property) {
+            $jsonKey = self::getJsonKey($property);
+            if ($jsonKey == null) {
+                continue;
+            }
+            $value = $property->getValue($this);
+
+            // Handle DateTime properties
+            $dateTypeAttr = $property->getAttributes(DateType::class)[0] ?? null;
+            if ($dateTypeAttr && $value instanceof DateTime) {
+                $dateType = $dateTypeAttr->newInstance()->type;
+                $value = ($dateType === DateType::TYPE_DATE)
+                    ? JsonSerializer::serializeDate($value)
+                    : JsonSerializer::serializeDateTime($value);
+            }
+
+            // Handle arrays with type annotations
+            $arrayTypeAttr = $property->getAttributes(ArrayType::class)[0] ?? null;
+            if ($arrayTypeAttr && is_array($value)) {
+                $arrayType = $arrayTypeAttr->newInstance()->type;
+                $value = JsonSerializer::serializeArray($value, $arrayType);
+            }
+
+            // Handle object
+            if (is_object($value)) {
+                $value = JsonSerializer::serializeObject($value);
+            }
+
+            if ($value !== null) {
+                $result[$jsonKey] = $value;
+            }
+        }
+
+        return $result;
+    }
+
+    /**
+     * Deserializes a JSON string into an instance of the calling class.
+     *
+     * @param string $json JSON string to deserialize.
+     * @return static Deserialized object.
+     * @throws JsonException If decoding fails or the result is not an array.
+     * @throws Exception If deserialization fails.
+     */
+    public static function fromJson(string $json): static
+    {
+        $decodedJson = JsonDecoder::decode($json);
+        if (!is_array($decodedJson)) {
+            throw new JsonException("Unexpected non-array decoded type: " . gettype($decodedJson));
+        }
+        return self::jsonDeserialize($decodedJson);
+    }
+
+    /**
+     * Deserializes an array into an instance of the calling class.
+     *
+     * @param array<string, mixed> $data Array data to deserialize.
+     * @return static Deserialized object.
+     * @throws JsonException If deserialization fails.
+     */
+    public static function jsonDeserialize(array $data): static
+    {
+        $reflectionClass = new \ReflectionClass(static::class);
+        $constructor = $reflectionClass->getConstructor();
+
+        if ($constructor === null) {
+            throw new JsonException("No constructor found.");
+        }
+
+        $args = [];
+        foreach ($reflectionClass->getProperties() as $property) {
+            $jsonKey = self::getJsonKey($property) ?? $property->getName();
+
+            if (array_key_exists($jsonKey, $data)) {
+                $value = $data[$jsonKey];
+
+                // Handle DateType annotation
+                $dateTypeAttr = $property->getAttributes(DateType::class)[0] ?? null;
+                if ($dateTypeAttr) {
+                    $dateType = $dateTypeAttr->newInstance()->type;
+                    if (!is_string($value)) {
+                        throw new JsonException("Unexpected non-string type for date.");
+                    }
+                    $value = ($dateType === DateType::TYPE_DATE)
+                        ? JsonDeserializer::deserializeDate($value)
+                        : JsonDeserializer::deserializeDateTime($value);
+                }
+
+                // Handle ArrayType annotation
+                $arrayTypeAttr = $property->getAttributes(ArrayType::class)[0] ?? null;
+                if (is_array($value) && $arrayTypeAttr) {
+                    $arrayType = $arrayTypeAttr->newInstance()->type;
+                    $value = JsonDeserializer::deserializeArray($value, $arrayType);
+                }
+
+                // Handle object
+                $type = $property->getType();
+                if (is_array($value) && $type instanceof ReflectionNamedType && !$type->isBuiltin()) {
+                    $value = JsonDeserializer::deserializeObject($value, $type->getName());
+                }
+
+                $args[$property->getName()] = $value;
+            } else {
+                $defaultValue = $property->getDefaultValue() ?? null;
+                $args[$property->getName()] = $defaultValue;
+            }
+        }
+        // @phpstan-ignore-next-line
+        return new static($args);
+    }
+
+    /**
+     * Retrieves the JSON key associated with a property.
+     *
+     * @param ReflectionProperty $property The reflection property.
+     * @return ?string The JSON key, or null if not available.
+     */
+    private static function getJsonKey(ReflectionProperty $property): ?string
+    {
+        $jsonPropertyAttr = $property->getAttributes(JsonProperty::class)[0] ?? null;
+        return $jsonPropertyAttr?->newInstance()?->name;
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/src/Core/Union.php b/seed/php-sdk/server-sent-events/src/Core/Union.php
new file mode 100644
index 00000000000..8608d2cae49
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Core/Union.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace Seed\Core;
+
+class Union
+{
+    /**
+     * @var string[]
+     */
+    public array $types;
+
+    public function __construct(string ...$strings)
+    {
+        $this->types = $strings;
+    }
+
+    public function __toString(): string
+    {
+        return implode(' | ', $this->types);
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/src/Core/Utils.php b/seed/php-sdk/server-sent-events/src/Core/Utils.php
new file mode 100644
index 00000000000..74416068d02
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Core/Utils.php
@@ -0,0 +1,61 @@
+<?php
+
+namespace Seed\Core;
+
+use DateTime;
+use Exception;
+use JsonException;
+
+class Utils
+{
+    /**
+     * Determines if the given type represents a map.
+     *
+     * @param mixed[]|array<string, mixed> $type The type definition from the annotation.
+     * @return bool True if the type is a map, false if it's a list.
+     */
+    public static function isMapType(array $type): bool
+    {
+        return count($type) === 1 && !array_is_list($type);
+    }
+
+    /**
+     * Casts the key to the appropriate type based on the key type.
+     *
+     * @param mixed $key The key to be cast.
+     * @param string $keyType The type to cast the key to ('string', 'integer', 'float').
+     * @return mixed The casted key.
+     * @throws JsonException
+     */
+    public static function castKey(mixed $key, string $keyType): mixed
+    {
+        if (!is_scalar($key)) {
+            throw new JsonException("Key must be a scalar type.");
+        }
+        return match ($keyType) {
+            'integer' => (int)$key,
+            'float' => (float)$key,
+            'string' => (string)$key,
+            default => $key,
+        };
+    }
+
+    /**
+     * Returns a human-readable representation of the input's type.
+     *
+     * @param mixed $input The input value to determine the type of.
+     * @return string A readable description of the input type.
+     */
+    public static function getReadableType(mixed $input): string
+    {
+        if (is_object($input)) {
+            return get_class($input);
+        } elseif (is_array($input)) {
+            return 'array(' . count($input) . ' items)';
+        } elseif (is_null($input)) {
+            return 'null';
+        } else {
+            return gettype($input);
+        }
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/src/Exceptions/SeedApiException.php b/seed/php-sdk/server-sent-events/src/Exceptions/SeedApiException.php
new file mode 100644
index 00000000000..41a85392b70
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Exceptions/SeedApiException.php
@@ -0,0 +1,53 @@
+<?php
+
+namespace Seed\Exceptions;
+
+use Throwable;
+
+/**
+ * This exception type will be thrown for any non-2XX API responses.
+ */
+class SeedApiException extends SeedException
+{
+    /**
+     * @var mixed $body
+     */
+    private mixed $body;
+
+    /**
+     * @param string $message
+     * @param int $statusCode
+     * @param mixed $body
+     * @param ?Throwable $previous
+     */
+    public function __construct(
+        string $message,
+        int $statusCode,
+        mixed $body,
+        ?Throwable $previous = null,
+    ) {
+        $this->body = $body;
+        parent::__construct($message, $statusCode, $previous);
+    }
+
+    /**
+     * Returns the body of the response that triggered the exception.
+     *
+     * @return mixed
+     */
+    public function getBody(): mixed
+    {
+        return $this->body;
+    }
+
+    /**
+     * @return string
+     */
+    public function __toString(): string
+    {
+        if (empty($this->body)) {
+            return "$this->message; Status Code: $this->code\n";
+        }
+        return "$this->message; Status Code: $this->code; Body: " . $this->body . "\n";
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/src/Exceptions/SeedException.php b/seed/php-sdk/server-sent-events/src/Exceptions/SeedException.php
new file mode 100644
index 00000000000..45703527673
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/Exceptions/SeedException.php
@@ -0,0 +1,12 @@
+<?php
+
+namespace Seed\Exceptions;
+
+use Exception;
+
+/**
+ * Base exception class for all exceptions thrown by the SDK.
+ */
+class SeedException extends Exception
+{
+}
diff --git a/seed/php-sdk/server-sent-events/src/SeedClient.php b/seed/php-sdk/server-sent-events/src/SeedClient.php
new file mode 100644
index 00000000000..d49132783ed
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/src/SeedClient.php
@@ -0,0 +1,58 @@
+<?php
+
+namespace Seed;
+
+use Seed\Completions\CompletionsClient;
+use GuzzleHttp\ClientInterface;
+use Seed\Core\RawClient;
+
+class SeedClient
+{
+    /**
+     * @var CompletionsClient $completions
+     */
+    public CompletionsClient $completions;
+
+    /**
+     * @var ?array{
+     *   baseUrl?: string,
+     *   client?: ClientInterface,
+     *   headers?: array<string, string>,
+     * } $options
+     */
+    private ?array $options;
+
+    /**
+     * @var RawClient $client
+     */
+    private RawClient $client;
+
+    /**
+     * @param ?array{
+     *   baseUrl?: string,
+     *   client?: ClientInterface,
+     *   headers?: array<string, string>,
+     * } $options
+     */
+    public function __construct(
+        ?array $options = null,
+    ) {
+        $defaultHeaders = [
+            'X-Fern-Language' => 'PHP',
+            'X-Fern-SDK-Name' => 'Seed',
+            'X-Fern-SDK-Version' => '0.0.1',
+        ];
+
+        $this->options = $options ?? [];
+        $this->options['headers'] = array_merge(
+            $defaultHeaders,
+            $this->options['headers'] ?? [],
+        );
+
+        $this->client = new RawClient(
+            options: $this->options,
+        );
+
+        $this->completions = new CompletionsClient($this->client);
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/tests/Seed/Core/DateArrayTypeTest.php b/seed/php-sdk/server-sent-events/tests/Seed/Core/DateArrayTypeTest.php
new file mode 100644
index 00000000000..8d93afc9e44
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/tests/Seed/Core/DateArrayTypeTest.php
@@ -0,0 +1,55 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+use Seed\Core\ArrayType;
+use DateTime;
+
+class DateArrayType extends SerializableType
+{
+    /**
+     * @var string[] $dates
+     */
+    #[ArrayType(['date'])]
+    #[JsonProperty('dates')]
+    public array $dates;
+
+    /**
+     * @param array{
+     *   dates: string[],
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->dates = $values['dates'];
+    }
+}
+
+class DateArrayTypeTest extends TestCase
+{
+    public function testDateTimeTypesInArrays(): void
+    {
+        $data = [
+            'dates' => ['2023-01-01', '2023-02-01', '2023-03-01']
+        ];
+
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+
+        $object = DateArrayType::fromJson($json);
+
+        $this->assertInstanceOf(DateTime::class, $object->dates[0], 'dates[0] should be a DateTime instance.');
+        $this->assertEquals('2023-01-01', $object->dates[0]->format('Y-m-d'), 'dates[0] should have the correct date.');
+        $this->assertInstanceOf(DateTime::class, $object->dates[1], 'dates[1] should be a DateTime instance.');
+        $this->assertEquals('2023-02-01', $object->dates[1]->format('Y-m-d'), 'dates[1] should have the correct date.');
+        $this->assertInstanceOf(DateTime::class, $object->dates[2], 'dates[2] should be a DateTime instance.');
+        $this->assertEquals('2023-03-01', $object->dates[2]->format('Y-m-d'), 'dates[2] should have the correct date.');
+
+        $serializedJson = $object->toJson();
+
+        $this->assertJsonStringEqualsJsonString($json, $serializedJson, 'Serialized JSON does not match original JSON for dates array.');
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/tests/Seed/Core/EmptyArraysTest.php b/seed/php-sdk/server-sent-events/tests/Seed/Core/EmptyArraysTest.php
new file mode 100644
index 00000000000..b44f3d093e6
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/tests/Seed/Core/EmptyArraysTest.php
@@ -0,0 +1,73 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+use Seed\Core\ArrayType;
+use Seed\Core\Union;
+
+class EmptyArraysType extends SerializableType
+{
+    /**
+     * @var string[] $emptyStringArray
+     */
+    #[ArrayType(['string'])]
+    #[JsonProperty('empty_string_array')]
+    public array $emptyStringArray;
+
+    /**
+     * @var array<string, string|null> $emptyMapArray
+     */
+    #[JsonProperty('empty_map_array')]
+    #[ArrayType(['integer' => new Union('string', 'null')])]
+    public array $emptyMapArray;
+
+    /**
+     * @var array<string|null> $emptyDatesArray
+     */
+    #[ArrayType([new Union('date', 'null')])]
+    #[JsonProperty('empty_dates_array')]
+    public array $emptyDatesArray;
+
+    /**
+     * @param array{
+     *   emptyStringArray: string[],
+     *   emptyMapArray: array<string, string|null>,
+     *   emptyDatesArray: array<string|null>,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->emptyStringArray = $values['emptyStringArray'];
+        $this->emptyMapArray = $values['emptyMapArray'];
+        $this->emptyDatesArray = $values['emptyDatesArray'];
+    }
+}
+
+class EmptyArraysTest extends TestCase
+{
+    public function testEmptyArrays(): void
+    {
+        $data = [
+            'empty_string_array' => [],
+            'empty_map_array' => [],
+            'empty_dates_array' => []
+        ];
+
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+
+        $object = EmptyArraysType::fromJson($json);
+
+        $serializedJson = $object->toJson();
+
+        $this->assertJsonStringEqualsJsonString($json, $serializedJson, 'Serialized JSON does not match original JSON for EmptyArraysType.');
+
+        // Check that arrays are empty
+        $this->assertEmpty($object->emptyStringArray, 'empty_string_array should be empty.');
+        $this->assertEmpty($object->emptyMapArray, 'empty_map_array should be empty.');
+        $this->assertEmpty($object->emptyDatesArray, 'empty_dates_array should be empty.');
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/tests/Seed/Core/EnumTest.php b/seed/php-sdk/server-sent-events/tests/Seed/Core/EnumTest.php
new file mode 100644
index 00000000000..ef5b8484dfd
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/tests/Seed/Core/EnumTest.php
@@ -0,0 +1,76 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use JsonSerializable;
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+use Seed\Core\ArrayType;
+
+enum Shape: string implements JsonSerializable
+{
+    case Square = "SQUARE";
+    case Circle = "CIRCLE";
+    case Triangle = "TRIANGLE";
+
+    /**
+     * @return string
+     */
+    public function jsonSerialize(): string
+    {
+        return $this->value;
+    }
+}
+
+class ShapeType extends SerializableType
+{
+    /**
+     * @var Shape $shape
+     */
+    #[JsonProperty('shape')]
+    public Shape $shape;
+
+    /**
+     * @var Shape[] $shapes
+     */
+    #[ArrayType([Shape::class])]
+    #[JsonProperty('shapes')]
+    public array $shapes;
+
+    /**
+     * @param Shape $shape
+     * @param Shape[] $shapes
+     */
+    public function __construct(
+        Shape $shape,
+        array $shapes,
+    ) {
+        $this->shape = $shape;
+        $this->shapes = $shapes;
+    }
+}
+
+class EnumTest extends TestCase
+{
+    public function testShapeEnumSerialization(): void
+    {
+        $object = new ShapeType(
+            Shape::Circle,
+            [Shape::Square, Shape::Circle, Shape::Triangle]
+        );
+
+        $expectedJson = json_encode([
+            'shape' => 'CIRCLE',
+            'shapes' => ['SQUARE', 'CIRCLE', 'TRIANGLE']
+        ], JSON_THROW_ON_ERROR);
+
+        $serializedJson = $object->toJson();
+
+        $this->assertJsonStringEqualsJsonString(
+            $expectedJson,
+            $serializedJson,
+            'Serialized JSON does not match expected JSON for shape and shapes properties.'
+        );
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/tests/Seed/Core/InvalidTypesTest.php b/seed/php-sdk/server-sent-events/tests/Seed/Core/InvalidTypesTest.php
new file mode 100644
index 00000000000..67bfd235b2f
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/tests/Seed/Core/InvalidTypesTest.php
@@ -0,0 +1,45 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+
+class InvalidType extends SerializableType
+{
+    /**
+     * @var int $integerProperty
+     */
+    #[JsonProperty('integer_property')]
+    public int $integerProperty;
+
+    /**
+     * @param array{
+     *   integerProperty: int,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->integerProperty = $values['integerProperty'];
+    }
+}
+
+class InvalidTypesTest extends TestCase
+{
+    public function testInvalidTypesThrowExceptions(): void
+    {
+        // Create test data with invalid type for integer_property (string instead of int)
+        $data = [
+            'integer_property' => 'not_an_integer'
+        ];
+
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+
+        $this->expectException(\TypeError::class);
+
+        // Attempt to deserialize invalid data
+        InvalidType::fromJson($json);
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/tests/Seed/Core/MixedDateArrayTypeTest.php b/seed/php-sdk/server-sent-events/tests/Seed/Core/MixedDateArrayTypeTest.php
new file mode 100644
index 00000000000..3bf18aec25b
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/tests/Seed/Core/MixedDateArrayTypeTest.php
@@ -0,0 +1,60 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+use Seed\Core\ArrayType;
+use Seed\Core\Union;
+use DateTime;
+
+class MixedDateArrayType extends SerializableType
+{
+    /**
+     * @var array<int, datetime|string|null> $mixedDates
+     */
+    #[ArrayType(['integer' => new Union('datetime', 'string', 'null')])]
+    #[JsonProperty('mixed_dates')]
+    public array $mixedDates;
+
+    /**
+     * @param array{
+     *   mixedDates: array<int, datetime|string|null>,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->mixedDates = $values['mixedDates'];
+    }
+}
+
+class MixedDateArrayTypeTest extends TestCase
+{
+    public function testDateTimeTypesInUnionArrays(): void
+    {
+        $data = [
+            'mixed_dates' => [
+                1 => '2023-01-01T12:00:00+00:00',
+                2 => null,
+                3 => 'Some String'
+            ]
+        ];
+
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+
+        $object = MixedDateArrayType::fromJson($json);
+
+        $this->assertInstanceOf(DateTime::class, $object->mixedDates[1], 'mixed_dates[1] should be a DateTime instance.');
+        $this->assertEquals('2023-01-01 12:00:00', $object->mixedDates[1]->format('Y-m-d H:i:s'), 'mixed_dates[1] should have the correct datetime.');
+
+        $this->assertNull($object->mixedDates[2], 'mixed_dates[2] should be null.');
+
+        $this->assertEquals('Some String', $object->mixedDates[3], 'mixed_dates[3] should be "Some String".');
+
+        $serializedJson = $object->toJson();
+
+        $this->assertJsonStringEqualsJsonString($json, $serializedJson, 'Serialized JSON does not match original JSON for mixed_dates.');
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/tests/Seed/Core/NestedUnionArrayTypeTest.php b/seed/php-sdk/server-sent-events/tests/Seed/Core/NestedUnionArrayTypeTest.php
new file mode 100644
index 00000000000..4667ecafcb9
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/tests/Seed/Core/NestedUnionArrayTypeTest.php
@@ -0,0 +1,99 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\Constant;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+use Seed\Core\ArrayType;
+use Seed\Core\Union;
+use DateTime;
+
+// Supporting Classes
+
+class TestNestedType extends SerializableType
+{
+    /**
+     * @var string $nestedProperty
+     */
+    #[JsonProperty('nested_property')]
+    public string $nestedProperty;
+
+    /**
+     * @param array{
+     *   nestedProperty: string,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->nestedProperty = $values['nestedProperty'];
+    }
+}
+
+class NestedUnionArrayType extends SerializableType
+{
+    /**
+     * @var array<int, array<int, TestNestedType|null|string>> $nestedArray
+     */
+    #[ArrayType(['integer' => ['integer' => new Union(TestNestedType::class, 'null', 'date')]])]
+    #[JsonProperty('nested_array')]
+    public array $nestedArray;
+
+    /**
+     * @param array{
+     *   nestedArray: array<int, array<int, TestNestedType|null|string>>,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->nestedArray = $values['nestedArray'];
+    }
+}
+
+class NestedUnionArrayTypeTest extends TestCase
+{
+    public function testNestedUnionTypesInArrays(): void
+    {
+        $data = [
+            'nested_array' => [
+                1 => [
+                    1 => ['nested_property' => 'Nested One'],
+                    2 => null,
+                    4 => '2023-01-02'
+                ],
+                2 => [
+                    5 => ['nested_property' => 'Nested Two'],
+                    7 => '2023-02-02'
+                ]
+            ]
+        ];
+
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+
+        $object = NestedUnionArrayType::fromJson($json);
+
+        // Level 1
+        $this->assertInstanceOf(TestNestedType::class, $object->nestedArray[1][1], 'nested_array[1][1] should be an instance of TestNestedType.');
+        $this->assertEquals('Nested One', $object->nestedArray[1][1]->nestedProperty, 'nested_array[1][1]->nestedProperty should match the original data.');
+
+        $this->assertNull($object->nestedArray[1][2], 'nested_array[1][2] should be null.');
+
+        // ensure dates are set with the default time
+        $this->assertInstanceOf(DateTime::class, $object->nestedArray[1][4], 'nested_array[1][4] should be a DateTime instance.');
+        $this->assertEquals('2023-01-02T00:00:00+00:00', $object->nestedArray[1][4]->format(Constant::DateTimeFormat), 'nested_array[1][4] should have the correct datetime.');
+
+        // Level 2
+        $this->assertInstanceOf(TestNestedType::class, $object->nestedArray[2][5], 'nested_array[2][5] should be an instance of TestNestedType.');
+        $this->assertEquals('Nested Two', $object->nestedArray[2][5]->nestedProperty, 'nested_array[2][5]->nestedProperty should match the original data.');
+
+        $this->assertInstanceOf(DateTime::class, $object->nestedArray[2][7], 'nested_array[1][4] should be a DateTime instance.');
+        $this->assertEquals('2023-02-02', $object->nestedArray[2][7]->format('Y-m-d'), 'nested_array[1][4] should have the correct date.');
+
+        $serializedJson = $object->toJson();
+
+        $this->assertJsonStringEqualsJsonString($json, $serializedJson, 'Serialized JSON does not match original JSON for nested_array.');
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/tests/Seed/Core/NullPropertyTypeTest.php b/seed/php-sdk/server-sent-events/tests/Seed/Core/NullPropertyTypeTest.php
new file mode 100644
index 00000000000..134296f56e3
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/tests/Seed/Core/NullPropertyTypeTest.php
@@ -0,0 +1,50 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+
+class NullPropertyType extends SerializableType
+{
+    /**
+     * @var string $nonNullProperty
+     */
+    #[JsonProperty('non_null_property')]
+    public string $nonNullProperty;
+
+    /**
+     * @var string|null $nullProperty
+     */
+    #[JsonProperty('null_property')]
+    public ?string $nullProperty;
+
+    /**
+     * @param array{
+     *   nonNullProperty: string,
+     *   nullProperty?: string|null,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->nonNullProperty = $values['nonNullProperty'];
+        $this->nullProperty = $values['nullProperty'] ?? null;
+    }
+}
+
+class NullPropertyTypeTest extends TestCase
+{
+    public function testNullPropertiesAreOmitted(): void
+    {
+        $object = new NullPropertyType(["nonNullProperty" => "Test String", "nullProperty" => null]);
+
+        $serializedObject = $object->jsonSerialize();
+
+        $this->assertArrayHasKey('non_null_property', $serializedObject, 'non_null_property should be present in the serialized JSON.');
+        $this->assertArrayNotHasKey('null_property', $serializedObject, 'null_property should be omitted from the serialized JSON.');
+
+        $this->assertEquals('Test String', $serializedObject['non_null_property'], 'non_null_property should have the correct value.');
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/tests/Seed/Core/NullableArrayTypeTest.php b/seed/php-sdk/server-sent-events/tests/Seed/Core/NullableArrayTypeTest.php
new file mode 100644
index 00000000000..bf6345e5c6f
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/tests/Seed/Core/NullableArrayTypeTest.php
@@ -0,0 +1,50 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+use Seed\Core\ArrayType;
+use Seed\Core\Union;
+
+class NullableArrayType extends SerializableType
+{
+    /**
+     * @var array<string|null> $nullableStringArray
+     */
+    #[ArrayType([new Union('string', 'null')])]
+    #[JsonProperty('nullable_string_array')]
+    public array $nullableStringArray;
+
+    /**
+     * @param array{
+     *   nullableStringArray: array<string|null>,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->nullableStringArray = $values['nullableStringArray'];
+    }
+}
+
+class NullableArrayTypeTest extends TestCase
+{
+    public function testNullableTypesInArrays(): void
+    {
+        $data = [
+            'nullable_string_array' => ['one', null, 'three']
+        ];
+
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+
+        $object = NullableArrayType::fromJson($json);
+
+        $this->assertEquals(['one', null, 'three'], $object->nullableStringArray, 'nullable_string_array should match the original data.');
+
+        $serializedJson = $object->toJson();
+
+        $this->assertJsonStringEqualsJsonString($json, $serializedJson, 'Serialized JSON does not match original JSON for nullable_string_array.');
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/tests/Seed/Core/RawClientTest.php b/seed/php-sdk/server-sent-events/tests/Seed/Core/RawClientTest.php
new file mode 100644
index 00000000000..e01ae63b41a
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/tests/Seed/Core/RawClientTest.php
@@ -0,0 +1,101 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use GuzzleHttp\Client;
+use GuzzleHttp\Handler\MockHandler;
+use GuzzleHttp\HandlerStack;
+use GuzzleHttp\Psr7\Response;
+use PHPUnit\Framework\TestCase;
+use Psr\Http\Message\RequestInterface;
+use Seed\Core\BaseApiRequest;
+use Seed\Core\JsonApiRequest;
+use Seed\Core\HttpMethod;
+use Seed\Core\RawClient;
+
+class RawClientTest extends TestCase
+{
+    private string $baseUrl = 'https://api.example.com';
+    private MockHandler $mockHandler;
+    private RawClient $rawClient;
+
+    protected function setUp(): void
+    {
+        $this->mockHandler = new MockHandler();
+        $handlerStack = HandlerStack::create($this->mockHandler);
+        $client = new Client(['handler' => $handlerStack]);
+        $this->rawClient = new RawClient(['client' => $client]);
+    }
+
+    public function testHeaders(): void
+    {
+        $this->mockHandler->append(new Response(200));
+
+        $request = new JsonApiRequest(
+            $this->baseUrl,
+            '/test',
+            HttpMethod::GET,
+            ['X-Custom-Header' => 'TestValue']
+        );
+
+        $this->sendRequest($request);
+
+        $lastRequest = $this->mockHandler->getLastRequest();
+        assert($lastRequest instanceof RequestInterface);
+        $this->assertEquals('application/json', $lastRequest->getHeaderLine('Content-Type'));
+        $this->assertEquals('TestValue', $lastRequest->getHeaderLine('X-Custom-Header'));
+    }
+
+    public function testQueryParameters(): void
+    {
+        $this->mockHandler->append(new Response(200));
+
+        $request = new JsonApiRequest(
+            $this->baseUrl,
+            '/test',
+            HttpMethod::GET,
+            [],
+            ['param1' => 'value1', 'param2' => ['a', 'b'], 'param3' => 'true']
+        );
+
+        $this->sendRequest($request);
+
+        $lastRequest = $this->mockHandler->getLastRequest();
+        assert($lastRequest instanceof RequestInterface);
+        $this->assertEquals(
+            'https://api.example.com/test?param1=value1&param2=a&param2=b&param3=true',
+            (string)$lastRequest->getUri()
+        );
+    }
+
+    public function testJsonBody(): void
+    {
+        $this->mockHandler->append(new Response(200));
+
+        $body = ['key' => 'value'];
+        $request = new JsonApiRequest(
+            $this->baseUrl,
+            '/test',
+            HttpMethod::POST,
+            [],
+            [],
+            $body
+        );
+
+        $this->sendRequest($request);
+
+        $lastRequest = $this->mockHandler->getLastRequest();
+        assert($lastRequest instanceof RequestInterface);
+        $this->assertEquals('application/json', $lastRequest->getHeaderLine('Content-Type'));
+        $this->assertEquals(json_encode($body), (string)$lastRequest->getBody());
+    }
+
+    private function sendRequest(BaseApiRequest $request): void
+    {
+        try {
+            $this->rawClient->sendRequest($request);
+        } catch (\Throwable $e) {
+            $this->fail('An exception was thrown: ' . $e->getMessage());
+        }
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/tests/Seed/Core/ScalarTypesTest.php b/seed/php-sdk/server-sent-events/tests/Seed/Core/ScalarTypesTest.php
new file mode 100644
index 00000000000..899e949836c
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/tests/Seed/Core/ScalarTypesTest.php
@@ -0,0 +1,121 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+use Seed\Core\ArrayType;
+use Seed\Core\Union;
+
+class ScalarTypesTestType extends SerializableType
+{
+    /**
+     * @var int $integerProperty
+     */
+    #[JsonProperty('integer_property')]
+    public int $integerProperty;
+
+    /**
+     * @var float $floatProperty
+     */
+    #[JsonProperty('float_property')]
+    public float $floatProperty;
+    /**
+     * @var float $otherFloatProperty
+     */
+    #[JsonProperty('other_float_property')]
+    public float $otherFloatProperty;
+
+    /**
+     * @var bool $booleanProperty
+     */
+    #[JsonProperty('boolean_property')]
+    public bool $booleanProperty;
+
+    /**
+     * @var string $stringProperty
+     */
+    #[JsonProperty('string_property')]
+    public string $stringProperty;
+
+    /**
+     * @var array<int|float> $intFloatArray
+     */
+    #[ArrayType([new Union('integer', 'float')])]
+    #[JsonProperty('int_float_array')]
+    public array $intFloatArray;
+
+    /**
+     * @var array<float> $floatArray
+     */
+    #[ArrayType(['float'])]
+    #[JsonProperty('float_array')]
+    public array $floatArray;
+
+    /**
+     * @var bool|null $nullableBooleanProperty
+     */
+    #[JsonProperty('nullable_boolean_property')]
+    public ?bool $nullableBooleanProperty;
+
+    /**
+     * @param array{
+     *   integerProperty: int,
+     *   floatProperty: float,
+     *   otherFloatProperty: float,
+     *   booleanProperty: bool,
+     *   stringProperty: string,
+     *   intFloatArray: array<int|float>,
+     *   floatArray: array<float>,
+     *   nullableBooleanProperty?: bool|null,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->integerProperty = $values['integerProperty'];
+        $this->floatProperty = $values['floatProperty'];
+        $this->otherFloatProperty = $values['otherFloatProperty'];
+        $this->booleanProperty = $values['booleanProperty'];
+        $this->stringProperty = $values['stringProperty'];
+        $this->intFloatArray = $values['intFloatArray'];
+        $this->floatArray = $values['floatArray'];
+        $this->nullableBooleanProperty = $values['nullableBooleanProperty'] ?? null;
+    }
+}
+
+class ScalarTypesTest extends TestCase
+{
+    public function testAllScalarTypesIncludingFloat(): void
+    {
+        // Create test data
+        $data = [
+            'integer_property' => 42,
+            'float_property' => 3.14159,
+            'other_float_property' => 3,
+            'boolean_property' => true,
+            'string_property' => 'Hello, World!',
+            'int_float_array' => [1, 2.5, 3, 4.75],
+            'float_array' => [1, 2, 3, 4] // ensure we handle "integer-looking" floats
+        ];
+
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+
+        $object = ScalarTypesTestType::fromJson($json);
+
+        $serializedJson = $object->toJson();
+
+        $this->assertJsonStringEqualsJsonString($json, $serializedJson, 'Serialized JSON does not match original JSON for ScalarTypesTest.');
+
+        // Check scalar properties
+        $this->assertEquals(42, $object->integerProperty, 'integer_property should be 42.');
+        $this->assertEquals(3.14159, $object->floatProperty, 'float_property should be 3.14159.');
+        $this->assertTrue($object->booleanProperty, 'boolean_property should be true.');
+        $this->assertEquals('Hello, World!', $object->stringProperty, 'string_property should be "Hello, World!".');
+        $this->assertNull($object->nullableBooleanProperty, 'nullable_boolean_property should be null.');
+
+        // Check int_float_array
+        $this->assertEquals([1, 2.5, 3, 4.75], $object->intFloatArray, 'int_float_array should match the original data.');
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/tests/Seed/Core/TestTypeTest.php b/seed/php-sdk/server-sent-events/tests/Seed/Core/TestTypeTest.php
new file mode 100644
index 00000000000..8e7ca1b825c
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/tests/Seed/Core/TestTypeTest.php
@@ -0,0 +1,201 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+use Seed\Core\DateType;
+use Seed\Core\ArrayType;
+use DateTime;
+use Seed\Core\Union;
+
+class TestNestedType1 extends SerializableType
+{
+    /**
+     * @var DateTime $nestedProperty
+     */
+    #[JsonProperty('nested_property')]
+    #[DateType(DateType::TYPE_DATE)]
+    public DateTime $nestedProperty;
+
+    /**
+     * @param array{
+     *   nestedProperty: DateTime,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->nestedProperty = $values['nestedProperty'];
+    }
+}
+
+class TestType extends SerializableType
+{
+    /**
+     * @var TestNestedType1 nestedType
+     */
+    #[JsonProperty('nested_type')]
+    public TestNestedType1 $nestedType;    /**
+
+     * @var string $simpleProperty
+     */
+    #[JsonProperty('simple_property')]
+    public string $simpleProperty;
+
+    /**
+     * @var DateTime $dateProperty
+     */
+    #[DateType(DateType::TYPE_DATE)]
+    #[JsonProperty('date_property')]
+    public DateTime $dateProperty;
+
+    /**
+     * @var DateTime $datetimeProperty
+     */
+    #[DateType(DateType::TYPE_DATETIME)]
+    #[JsonProperty('datetime_property')]
+    public DateTime $datetimeProperty;
+
+    /**
+     * @var array<string> $stringArray
+     */
+    #[ArrayType(['string'])]
+    #[JsonProperty('string_array')]
+    public array $stringArray;
+
+    /**
+     * @var array<string, int> $mapProperty
+     */
+    #[ArrayType(['string' => 'integer'])]
+    #[JsonProperty('map_property')]
+    public array $mapProperty;
+
+    /**
+     * @var array<int, TestNestedType1|null> $objectArray
+     */
+    #[ArrayType(['integer' => new Union(TestNestedType1::class, 'null')])]
+    #[JsonProperty('object_array')]
+    public array $objectArray;
+
+    /**
+     * @var array<int, array<int, string|null>> $nestedArray
+     */
+    #[ArrayType(['integer' => ['integer' => new Union('string', 'null')]])]
+    #[JsonProperty('nested_array')]
+    public array $nestedArray;
+
+    /**
+     * @var array<string|null> $datesArray
+     */
+    #[ArrayType([new Union('date', 'null')])]
+    #[JsonProperty('dates_array')]
+    public array $datesArray;
+
+    /**
+     * @var string|null $nullableProperty
+     */
+    #[JsonProperty('nullable_property')]
+    public ?string $nullableProperty;
+
+    /**
+     * @param array{
+     *   nestedType: TestNestedType1,
+     *   simpleProperty: string,
+     *   dateProperty: DateTime,
+     *   datetimeProperty: DateTime,
+     *   stringArray: array<string>,
+     *   mapProperty: array<string, int>,
+     *   objectArray: array<int, TestNestedType1|null>,
+     *   nestedArray: array<int, array<int, string|null>>,
+     *   datesArray: array<string|null>,
+     *   nullableProperty?: string|null,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->nestedType = $values['nestedType'];
+        $this->simpleProperty = $values['simpleProperty'];
+        $this->dateProperty = $values['dateProperty'];
+        $this->datetimeProperty = $values['datetimeProperty'];
+        $this->stringArray = $values['stringArray'];
+        $this->mapProperty = $values['mapProperty'];
+        $this->objectArray = $values['objectArray'];
+        $this->nestedArray = $values['nestedArray'];
+        $this->datesArray = $values['datesArray'];
+        $this->nullableProperty = $values['nullableProperty'] ?? null;
+    }
+}
+
+class TestTypeTest extends TestCase
+{
+    /**
+     * Test serialization and deserialization of all types in TestType
+     */
+    public function testSerializationAndDeserialization(): void
+    {
+        // Create test data
+        $data = [
+            'nested_type' => ['nested_property' => '1995-07-20'],
+            'simple_property' => 'Test String',
+            // 'nullable_property' is omitted to test null serialization
+            'date_property' => '2023-01-01',
+            'datetime_property' => '2023-01-01T12:34:56+00:00',
+            'string_array' => ['one', 'two', 'three'],
+            'map_property' => ['key1' => 1, 'key2' => 2],
+            'object_array' => [
+                1 => ['nested_property' =>  '2021-07-20'],
+                2 => null, // Testing nullable objects in array
+            ],
+            'nested_array' => [
+                1 => [1 => 'value1', 2 => null], // Testing nullable strings in nested array
+                2 => [3 => 'value3', 4 => 'value4']
+            ],
+            'dates_array' => ['2023-01-01', null, '2023-03-01'] // Testing nullable dates in array
+        ];
+
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+
+        $object = TestType::fromJson($json);
+
+        $serializedJson = $object->toJson();
+
+        $this->assertJsonStringEqualsJsonString($json, $serializedJson, 'The serialized JSON does not match the original JSON.');
+
+        // Check that nullable property is null and not included in JSON
+        $this->assertNull($object->nullableProperty, 'Nullable property should be null.');
+        // @phpstan-ignore-next-line
+        $this->assertFalse(array_key_exists('nullable_property', json_decode($serializedJson, true)), 'Nullable property should be omitted from JSON.');
+
+        // Check date properties
+        $this->assertInstanceOf(DateTime::class, $object->dateProperty, 'date_property should be a DateTime instance.');
+        $this->assertEquals('2023-01-01', $object->dateProperty->format('Y-m-d'), 'date_property should have the correct date.');
+
+        $this->assertInstanceOf(DateTime::class, $object->datetimeProperty, 'datetime_property should be a DateTime instance.');
+        $this->assertEquals('2023-01-01 12:34:56', $object->datetimeProperty->format('Y-m-d H:i:s'), 'datetime_property should have the correct datetime.');
+
+        // Check scalar arrays
+        $this->assertEquals(['one', 'two', 'three'], $object->stringArray, 'string_array should match the original data.');
+        $this->assertEquals(['key1' => 1, 'key2' => 2], $object->mapProperty, 'map_property should match the original data.');
+
+        // Check object array with nullable elements
+        $this->assertInstanceOf(TestNestedType1::class, $object->objectArray[1], 'object_array[1] should be an instance of TestNestedType1.');
+        $this->assertEquals('2021-07-20', $object->objectArray[1]->nestedProperty->format('Y-m-d'), 'object_array[1]->nestedProperty should match the original data.');
+        $this->assertNull($object->objectArray[2], 'object_array[2] should be null.');
+
+        // Check nested array with nullable strings
+        $this->assertEquals('value1', $object->nestedArray[1][1], 'nested_array[1][1] should match the original data.');
+        $this->assertNull($object->nestedArray[1][2], 'nested_array[1][2] should be null.');
+        $this->assertEquals('value3', $object->nestedArray[2][3], 'nested_array[2][3] should match the original data.');
+        $this->assertEquals('value4', $object->nestedArray[2][4], 'nested_array[2][4] should match the original data.');
+
+        // Check dates array with nullable DateTime objects
+        $this->assertInstanceOf(DateTime::class, $object->datesArray[0], 'dates_array[0] should be a DateTime instance.');
+        $this->assertEquals('2023-01-01', $object->datesArray[0]->format('Y-m-d'), 'dates_array[0] should have the correct date.');
+        $this->assertNull($object->datesArray[1], 'dates_array[1] should be null.');
+        $this->assertInstanceOf(DateTime::class, $object->datesArray[2], 'dates_array[2] should be a DateTime instance.');
+        $this->assertEquals('2023-03-01', $object->datesArray[2]->format('Y-m-d'), 'dates_array[2] should have the correct date.');
+    }
+}
diff --git a/seed/php-sdk/server-sent-events/tests/Seed/Core/UnionArrayTypeTest.php b/seed/php-sdk/server-sent-events/tests/Seed/Core/UnionArrayTypeTest.php
new file mode 100644
index 00000000000..8d0998f4b7e
--- /dev/null
+++ b/seed/php-sdk/server-sent-events/tests/Seed/Core/UnionArrayTypeTest.php
@@ -0,0 +1,56 @@
+<?php
+
+namespace Seed\Tests\Core;
+
+use PHPUnit\Framework\TestCase;
+use Seed\Core\SerializableType;
+use Seed\Core\JsonProperty;
+use Seed\Core\ArrayType;
+use Seed\Core\Union;
+
+class UnionArrayType extends SerializableType
+{
+    /**
+     * @var array<int, string|int|null> $mixedArray
+     */
+    #[ArrayType(['integer' => new Union('string', 'integer', 'null')])]
+    #[JsonProperty('mixed_array')]
+    public array $mixedArray;
+
+    /**
+     * @param array{
+     *   mixedArray: array<int, string|int|null>,
+     * } $values
+     */
+    public function __construct(
+        array $values,
+    ) {
+        $this->mixedArray = $values['mixedArray'];
+    }
+}
+
+class UnionArrayTypeTest extends TestCase
+{
+    public function testUnionTypesInArrays(): void
+    {
+        $data = [
+            'mixed_array' => [
+                1 => 'one',
+                2 => 2,
+                3 => null
+            ]
+        ];
+
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+
+        $object = UnionArrayType::fromJson($json);
+
+        $this->assertEquals('one', $object->mixedArray[1], 'mixed_array[1] should be "one".');
+        $this->assertEquals(2, $object->mixedArray[2], 'mixed_array[2] should be 2.');
+        $this->assertNull($object->mixedArray[3], 'mixed_array[3] should be null.');
+
+        $serializedJson = $object->toJson();
+
+        $this->assertJsonStringEqualsJsonString($json, $serializedJson, 'Serialized JSON does not match original JSON for mixed_array.');
+    }
+}
diff --git a/seed/postman/server-sent-events/collection.json b/seed/postman/server-sent-events/collection.json
index a0cea86dec9..857ab05350e 100644
--- a/seed/postman/server-sent-events/collection.json
+++ b/seed/postman/server-sent-events/collection.json
@@ -34,12 +34,18 @@
               "query": [],
               "variable": []
             },
-            "header": [],
+            "header": [
+              {
+                "type": "text",
+                "key": "Content-Type",
+                "value": "application/json"
+              }
+            ],
             "method": "POST",
             "auth": null,
             "body": {
               "mode": "raw",
-              "raw": "{\n    \"query\": \"example\"\n}",
+              "raw": "{\n    \"query\": \"string\"\n}",
               "options": {
                 "raw": {
                   "language": "json"
@@ -47,7 +53,48 @@
               }
             }
           },
-          "response": []
+          "response": [
+            {
+              "name": "Success",
+              "status": "OK",
+              "code": 200,
+              "originalRequest": {
+                "description": null,
+                "url": {
+                  "raw": "{{baseUrl}}/stream",
+                  "host": [
+                    "{{baseUrl}}"
+                  ],
+                  "path": [
+                    "stream"
+                  ],
+                  "query": [],
+                  "variable": []
+                },
+                "header": [
+                  {
+                    "type": "text",
+                    "key": "Content-Type",
+                    "value": "application/json"
+                  }
+                ],
+                "method": "POST",
+                "auth": null,
+                "body": {
+                  "mode": "raw",
+                  "raw": "{\n    \"query\": \"string\"\n}",
+                  "options": {
+                    "raw": {
+                      "language": "json"
+                    }
+                  }
+                }
+              },
+              "description": null,
+              "body": "[\n    {\n        \"delta\": \"string\",\n        \"tokens\": 1\n    },\n    {\n        \"delta\": \"string\",\n        \"tokens\": 1\n    }\n]",
+              "_postman_previewlanguage": "json"
+            }
+          ]
         }
       ]
     }
diff --git a/seed/pydantic/server-sent-events/.github/workflows/ci.yml b/seed/pydantic/server-sent-events/.github/workflows/ci.yml
index 17b9d4fa0e8..b204fa604e2 100644
--- a/seed/pydantic/server-sent-events/.github/workflows/ci.yml
+++ b/seed/pydantic/server-sent-events/.github/workflows/ci.yml
@@ -34,7 +34,7 @@ jobs:
         run: poetry install
 
       - name: Test
-        run: poetry run pytest ./tests/custom/
+        run: poetry run pytest -rP .
 
   publish:
     needs: [compile, test]
diff --git a/seed/pydantic/server-sent-events/pyproject.toml b/seed/pydantic/server-sent-events/pyproject.toml
index 3ecc58493cc..e5b0d831e44 100644
--- a/seed/pydantic/server-sent-events/pyproject.toml
+++ b/seed/pydantic/server-sent-events/pyproject.toml
@@ -50,6 +50,9 @@ asyncio_mode = "auto"
 [tool.mypy]
 plugins = ["pydantic.mypy"]
 
+[tool.ruff]
+line-length = 120
+
 
 [build-system]
 requires = ["poetry-core"]
diff --git a/seed/pydantic/server-sent-events/src/seed/server_sent_events/core/__init__.py b/seed/pydantic/server-sent-events/src/seed/server_sent_events/core/__init__.py
index 85460274fba..9c7cd65aa25 100644
--- a/seed/pydantic/server-sent-events/src/seed/server_sent_events/core/__init__.py
+++ b/seed/pydantic/server-sent-events/src/seed/server_sent_events/core/__init__.py
@@ -5,7 +5,6 @@
     IS_PYDANTIC_V2,
     UniversalBaseModel,
     UniversalRootModel,
-    deep_union_pydantic_dicts,
     parse_obj_as,
     universal_field_validator,
     universal_root_validator,
@@ -18,7 +17,6 @@
     "IS_PYDANTIC_V2",
     "UniversalBaseModel",
     "UniversalRootModel",
-    "deep_union_pydantic_dicts",
     "parse_obj_as",
     "serialize_datetime",
     "universal_field_validator",
diff --git a/seed/pydantic/server-sent-events/src/seed/server_sent_events/core/datetime_utils.py b/seed/pydantic/server-sent-events/src/seed/server_sent_events/core/datetime_utils.py
index 47344e9d9cc..7c9864a944c 100644
--- a/seed/pydantic/server-sent-events/src/seed/server_sent_events/core/datetime_utils.py
+++ b/seed/pydantic/server-sent-events/src/seed/server_sent_events/core/datetime_utils.py
@@ -13,9 +13,7 @@ def serialize_datetime(v: dt.datetime) -> str:
     """
 
     def _serialize_zoned_datetime(v: dt.datetime) -> str:
-        if v.tzinfo is not None and v.tzinfo.tzname(None) == dt.timezone.utc.tzname(
-            None
-        ):
+        if v.tzinfo is not None and v.tzinfo.tzname(None) == dt.timezone.utc.tzname(None):
             # UTC is a special case where we use "Z" at the end instead of "+00:00"
             return v.isoformat().replace("+00:00", "Z")
         else:
diff --git a/seed/pydantic/server-sent-events/src/seed/server_sent_events/core/pydantic_utilities.py b/seed/pydantic/server-sent-events/src/seed/server_sent_events/core/pydantic_utilities.py
index 1a4cd514c6a..bbe1de41431 100644
--- a/seed/pydantic/server-sent-events/src/seed/server_sent_events/core/pydantic_utilities.py
+++ b/seed/pydantic/server-sent-events/src/seed/server_sent_events/core/pydantic_utilities.py
@@ -4,7 +4,8 @@
 import datetime as dt
 import typing
 from collections import defaultdict
-from functools import wraps
+
+import typing_extensions
 
 import pydantic
 
@@ -54,19 +55,6 @@
 Model = typing.TypeVar("Model", bound=pydantic.BaseModel)
 
 
-def deep_union_pydantic_dicts(
-    source: typing.Dict[str, typing.Any], destination: typing.Dict[str, typing.Any]
-) -> typing.Dict[str, typing.Any]:
-    for key, value in source.items():
-        if isinstance(value, dict):
-            node = destination.setdefault(key, {})
-            deep_union_pydantic_dicts(value, node)
-        else:
-            destination[key] = value
-
-    return destination
-
-
 def parse_obj_as(type_: typing.Type[T], object_: typing.Any) -> T:
     if IS_PYDANTIC_V2:
         adapter = pydantic.TypeAdapter(type_)  # type: ignore # Pydantic v2
@@ -92,6 +80,8 @@ class Config:
         smart_union = True
         allow_population_by_field_name = True
         json_encoders = {dt.datetime: serialize_datetime}
+        # Allow fields begining with `model_` to be used in the model
+        protected_namespaces = ()
 
     def json(self, **kwargs: typing.Any) -> str:
         kwargs_with_defaults: typing.Any = {
@@ -105,44 +95,107 @@ def json(self, **kwargs: typing.Any) -> str:
             return super().json(**kwargs_with_defaults)
 
     def dict(self, **kwargs: typing.Any) -> typing.Dict[str, typing.Any]:
-        kwargs_with_defaults_exclude_unset: typing.Any = {
-            "by_alias": True,
-            "exclude_unset": True,
-            **kwargs,
-        }
-        kwargs_with_defaults_exclude_none: typing.Any = {
-            "by_alias": True,
-            "exclude_none": True,
-            **kwargs,
-        }
-
+        """
+        Override the default dict method to `exclude_unset` by default. This function patches
+        `exclude_unset` to work include fields within non-None default values.
+        """
+        # Note: the logic here is multi-plexed given the levers exposed in Pydantic V1 vs V2
+        # Pydantic V1's .dict can be extremely slow, so we do not want to call it twice.
+        #
+        # We'd ideally do the same for Pydantic V2, but it shells out to a library to serialize models
+        # that we have less control over, and this is less intrusive than custom serializers for now.
         if IS_PYDANTIC_V2:
+            kwargs_with_defaults_exclude_unset: typing.Any = {
+                **kwargs,
+                "by_alias": True,
+                "exclude_unset": True,
+                "exclude_none": False,
+            }
+            kwargs_with_defaults_exclude_none: typing.Any = {
+                **kwargs,
+                "by_alias": True,
+                "exclude_none": True,
+                "exclude_unset": False,
+            }
             return deep_union_pydantic_dicts(
                 super().model_dump(**kwargs_with_defaults_exclude_unset),  # type: ignore # Pydantic v2
                 super().model_dump(**kwargs_with_defaults_exclude_none),  # type: ignore # Pydantic v2
             )
+
         else:
-            return deep_union_pydantic_dicts(
-                super().dict(**kwargs_with_defaults_exclude_unset),
-                super().dict(**kwargs_with_defaults_exclude_none),
-            )
+            _fields_set = self.__fields_set__.copy()
+
+            fields = _get_model_fields(self.__class__)
+            for name, field in fields.items():
+                if name not in _fields_set:
+                    default = _get_field_default(field)
+
+                    # If the default values are non-null act like they've been set
+                    # This effectively allows exclude_unset to work like exclude_none where
+                    # the latter passes through intentionally set none values.
+                    if default is not None or ("exclude_unset" in kwargs and not kwargs["exclude_unset"]):
+                        _fields_set.add(name)
+
+                        if default is not None:
+                            self.__fields_set__.add(name)
+
+            kwargs_with_defaults_exclude_unset_include_fields: typing.Any = {
+                "by_alias": True,
+                "exclude_unset": True,
+                "include": _fields_set,
+                **kwargs,
+            }
+
+            return super().dict(**kwargs_with_defaults_exclude_unset_include_fields)
+
+
+def _union_list_of_pydantic_dicts(
+    source: typing.List[typing.Any], destination: typing.List[typing.Any]
+) -> typing.List[typing.Any]:
+    converted_list: typing.List[typing.Any] = []
+    for i, item in enumerate(source):
+        destination_value = destination[i]  # type: ignore
+        if isinstance(item, dict):
+            converted_list.append(deep_union_pydantic_dicts(item, destination_value))
+        elif isinstance(item, list):
+            converted_list.append(_union_list_of_pydantic_dicts(item, destination_value))
+        else:
+            converted_list.append(item)
+    return converted_list
+
+
+def deep_union_pydantic_dicts(
+    source: typing.Dict[str, typing.Any], destination: typing.Dict[str, typing.Any]
+) -> typing.Dict[str, typing.Any]:
+    for key, value in source.items():
+        node = destination.setdefault(key, {})
+        if isinstance(value, dict):
+            deep_union_pydantic_dicts(value, node)
+        # Note: we do not do this same processing for sets given we do not have sets of models
+        # and given the sets are unordered, the processing of the set and matching objects would
+        # be non-trivial.
+        elif isinstance(value, list):
+            destination[key] = _union_list_of_pydantic_dicts(value, node)
+        else:
+            destination[key] = value
+
+    return destination
 
 
-UniversalRootModel: typing.Type[pydantic.BaseModel]
 if IS_PYDANTIC_V2:
 
     class V2RootModel(UniversalBaseModel, pydantic.RootModel):  # type: ignore # Pydantic v2
         pass
 
-    UniversalRootModel = V2RootModel
+    UniversalRootModel: typing_extensions.TypeAlias = V2RootModel  # type: ignore
 else:
-    UniversalRootModel = UniversalBaseModel
+    UniversalRootModel: typing_extensions.TypeAlias = UniversalBaseModel  # type: ignore
 
 
 def encode_by_type(o: typing.Any) -> typing.Any:
-    encoders_by_class_tuples: typing.Dict[
-        typing.Callable[[typing.Any], typing.Any], typing.Tuple[typing.Any, ...]
-    ] = defaultdict(tuple)
+    encoders_by_class_tuples: typing.Dict[typing.Callable[[typing.Any], typing.Any], typing.Tuple[typing.Any, ...]] = (
+        defaultdict(tuple)
+    )
     for type_, encoder in encoders_by_type.items():
         encoders_by_class_tuples[encoder] += (type_,)
 
@@ -153,11 +206,11 @@ def encode_by_type(o: typing.Any) -> typing.Any:
             return encoder(o)
 
 
-def update_forward_refs(model: typing.Type["Model"]) -> None:
+def update_forward_refs(model: typing.Type["Model"], **localns: typing.Any) -> None:
     if IS_PYDANTIC_V2:
         model.model_rebuild(raise_errors=False)  # type: ignore # Pydantic v2
     else:
-        model.update_forward_refs()
+        model.update_forward_refs(**localns)
 
 
 # Mirrors Pydantic's internal typing
@@ -168,37 +221,45 @@ def universal_root_validator(
     pre: bool = False,
 ) -> typing.Callable[[AnyCallable], AnyCallable]:
     def decorator(func: AnyCallable) -> AnyCallable:
-        @wraps(func)
-        def validate(*args: typing.Any, **kwargs: typing.Any) -> AnyCallable:
-            if IS_PYDANTIC_V2:
-                wrapped_func = pydantic.model_validator("before" if pre else "after")(
-                    func
-                )  # type: ignore # Pydantic v2
-            else:
-                wrapped_func = pydantic.root_validator(pre=pre)(func)  # type: ignore # Pydantic v1
+        if IS_PYDANTIC_V2:
+            return pydantic.model_validator(mode="before" if pre else "after")(func)  # type: ignore # Pydantic v2
+        else:
+            return pydantic.root_validator(pre=pre)(func)  # type: ignore # Pydantic v1
 
-            return wrapped_func(*args, **kwargs)
+    return decorator
 
-        return validate
+
+def universal_field_validator(field_name: str, pre: bool = False) -> typing.Callable[[AnyCallable], AnyCallable]:
+    def decorator(func: AnyCallable) -> AnyCallable:
+        if IS_PYDANTIC_V2:
+            return pydantic.field_validator(field_name, mode="before" if pre else "after")(func)  # type: ignore # Pydantic v2
+        else:
+            return pydantic.validator(field_name, pre=pre)(func)  # type: ignore # Pydantic v1
 
     return decorator
 
 
-def universal_field_validator(
-    field_name: str, pre: bool = False
-) -> typing.Callable[[AnyCallable], AnyCallable]:
-    def decorator(func: AnyCallable) -> AnyCallable:
-        @wraps(func)
-        def validate(*args: typing.Any, **kwargs: typing.Any) -> AnyCallable:
-            if IS_PYDANTIC_V2:
-                wrapped_func = pydantic.field_validator(
-                    field_name, mode="before" if pre else "after"
-                )(func)  # type: ignore # Pydantic v2
-            else:
-                wrapped_func = pydantic.validator(field_name, pre=pre)(func)
+PydanticField = typing.Union[ModelField, pydantic.fields.FieldInfo]
 
-            return wrapped_func(*args, **kwargs)
 
-        return validate
+def _get_model_fields(
+    model: typing.Type["Model"],
+) -> typing.Mapping[str, PydanticField]:
+    if IS_PYDANTIC_V2:
+        return model.model_fields  # type: ignore # Pydantic v2
+    else:
+        return model.__fields__  # type: ignore # Pydantic v1
 
-    return decorator
+
+def _get_field_default(field: PydanticField) -> typing.Any:
+    try:
+        value = field.get_default()  # type: ignore # Pydantic < v1.10.15
+    except:
+        value = field.default
+    if IS_PYDANTIC_V2:
+        from pydantic_core import PydanticUndefined
+
+        if value == PydanticUndefined:
+            return None
+        return value
+    return value
diff --git a/seed/pydantic/server-sent-events/src/seed/server_sent_events/core/serialization.py b/seed/pydantic/server-sent-events/src/seed/server_sent_events/core/serialization.py
index 5400ca0bc3b..cb5dcbf93a9 100644
--- a/seed/pydantic/server-sent-events/src/seed/server_sent_events/core/serialization.py
+++ b/seed/pydantic/server-sent-events/src/seed/server_sent_events/core/serialization.py
@@ -1,10 +1,13 @@
 # This file was auto-generated by Fern from our API Definition.
 
 import collections
+import inspect
 import typing
 
 import typing_extensions
 
+import pydantic
+
 
 class FieldMetadata:
     """
@@ -29,6 +32,7 @@ def convert_and_respect_annotation_metadata(
     object_: typing.Any,
     annotation: typing.Any,
     inner_type: typing.Optional[typing.Any] = None,
+    direction: typing.Literal["read", "write"],
 ) -> typing.Any:
     """
     Respect the metadata annotations on a field, such as aliasing. This function effectively
@@ -56,49 +60,77 @@ def convert_and_respect_annotation_metadata(
         inner_type = annotation
 
     clean_type = _remove_annotations(inner_type)
-    if typing_extensions.is_typeddict(clean_type) and isinstance(
-        object_, typing.Mapping
+    # Pydantic models
+    if (
+        inspect.isclass(clean_type)
+        and issubclass(clean_type, pydantic.BaseModel)
+        and isinstance(object_, typing.Mapping)
     ):
-        return _convert_typeddict(object_, clean_type)
+        return _convert_mapping(object_, clean_type, direction)
+    # TypedDicts
+    if typing_extensions.is_typeddict(clean_type) and isinstance(object_, typing.Mapping):
+        return _convert_mapping(object_, clean_type, direction)
 
     if (
-        # If you're iterating on a string, do not bother to coerce it to a sequence.
-        (not isinstance(object_, str))
-        and (
-            (
-                (
-                    typing_extensions.get_origin(clean_type) == typing.List
-                    or typing_extensions.get_origin(clean_type) == list
-                    or clean_type == typing.List
-                )
-                and isinstance(object_, typing.List)
-            )
-            or (
-                (
-                    typing_extensions.get_origin(clean_type) == typing.Set
-                    or typing_extensions.get_origin(clean_type) == set
-                    or clean_type == typing.Set
-                )
-                and isinstance(object_, typing.Set)
+        typing_extensions.get_origin(clean_type) == typing.Dict
+        or typing_extensions.get_origin(clean_type) == dict
+        or clean_type == typing.Dict
+    ) and isinstance(object_, typing.Dict):
+        key_type = typing_extensions.get_args(clean_type)[0]
+        value_type = typing_extensions.get_args(clean_type)[1]
+
+        return {
+            key: convert_and_respect_annotation_metadata(
+                object_=value,
+                annotation=annotation,
+                inner_type=value_type,
+                direction=direction,
             )
-            or (
-                (
-                    typing_extensions.get_origin(clean_type) == typing.Sequence
-                    or typing_extensions.get_origin(clean_type)
-                    == collections.abc.Sequence
-                    or clean_type == typing.Sequence
+            for key, value in object_.items()
+        }
+
+    # If you're iterating on a string, do not bother to coerce it to a sequence.
+    if not isinstance(object_, str):
+        if (
+            typing_extensions.get_origin(clean_type) == typing.Set
+            or typing_extensions.get_origin(clean_type) == set
+            or clean_type == typing.Set
+        ) and isinstance(object_, typing.Set):
+            inner_type = typing_extensions.get_args(clean_type)[0]
+            return {
+                convert_and_respect_annotation_metadata(
+                    object_=item,
+                    annotation=annotation,
+                    inner_type=inner_type,
+                    direction=direction,
                 )
-                and isinstance(object_, typing.Sequence)
+                for item in object_
+            }
+        elif (
+            (
+                typing_extensions.get_origin(clean_type) == typing.List
+                or typing_extensions.get_origin(clean_type) == list
+                or clean_type == typing.List
             )
-        )
-    ):
-        inner_type = typing_extensions.get_args(clean_type)[0]
-        return [
-            convert_and_respect_annotation_metadata(
-                object_=item, annotation=annotation, inner_type=inner_type
+            and isinstance(object_, typing.List)
+        ) or (
+            (
+                typing_extensions.get_origin(clean_type) == typing.Sequence
+                or typing_extensions.get_origin(clean_type) == collections.abc.Sequence
+                or clean_type == typing.Sequence
             )
-            for item in object_
-        ]
+            and isinstance(object_, typing.Sequence)
+        ):
+            inner_type = typing_extensions.get_args(clean_type)[0]
+            return [
+                convert_and_respect_annotation_metadata(
+                    object_=item,
+                    annotation=annotation,
+                    inner_type=inner_type,
+                    direction=direction,
+                )
+                for item in object_
+            ]
 
     if typing_extensions.get_origin(clean_type) == typing.Union:
         # We should be able to ~relatively~ safely try to convert keys against all
@@ -107,7 +139,10 @@ def convert_and_respect_annotation_metadata(
         # Or if another member aliases a field of the same name that another member does not.
         for member in typing_extensions.get_args(clean_type):
             object_ = convert_and_respect_annotation_metadata(
-                object_=object_, annotation=annotation, inner_type=member
+                object_=object_,
+                annotation=annotation,
+                inner_type=member,
+                direction=direction,
             )
         return object_
 
@@ -120,18 +155,34 @@ def convert_and_respect_annotation_metadata(
     return object_
 
 
-def _convert_typeddict(
-    object_: typing.Mapping[str, object], expected_type: typing.Any
+def _convert_mapping(
+    object_: typing.Mapping[str, object],
+    expected_type: typing.Any,
+    direction: typing.Literal["read", "write"],
 ) -> typing.Mapping[str, object]:
     converted_object: typing.Dict[str, object] = {}
     annotations = typing_extensions.get_type_hints(expected_type, include_extras=True)
+    aliases_to_field_names = _get_alias_to_field_name(annotations)
     for key, value in object_.items():
-        type_ = annotations.get(key)
+        if direction == "read" and key in aliases_to_field_names:
+            dealiased_key = aliases_to_field_names.get(key)
+            if dealiased_key is not None:
+                type_ = annotations.get(dealiased_key)
+        else:
+            type_ = annotations.get(key)
+        # Note you can't get the annotation by the field name if you're in read mode, so you must check the aliases map
+        #
+        # So this is effectively saying if we're in write mode, and we don't have a type, or if we're in read mode and we don't have an alias
+        # then we can just pass the value through as is
         if type_ is None:
             converted_object[key] = value
+        elif direction == "read" and key not in aliases_to_field_names:
+            converted_object[key] = convert_and_respect_annotation_metadata(
+                object_=value, annotation=type_, direction=direction
+            )
         else:
-            converted_object[_alias_key(key, type_)] = (
-                convert_and_respect_annotation_metadata(object_=value, annotation=type_)
+            converted_object[_alias_key(key, type_, direction, aliases_to_field_names)] = (
+                convert_and_respect_annotation_metadata(object_=value, annotation=type_, direction=direction)
             )
     return converted_object
 
@@ -165,7 +216,39 @@ def _remove_annotations(type_: typing.Any) -> typing.Any:
     return type_
 
 
-def _alias_key(key: str, type_: typing.Any) -> str:
+def get_alias_to_field_mapping(type_: typing.Any) -> typing.Dict[str, str]:
+    annotations = typing_extensions.get_type_hints(type_, include_extras=True)
+    return _get_alias_to_field_name(annotations)
+
+
+def get_field_to_alias_mapping(type_: typing.Any) -> typing.Dict[str, str]:
+    annotations = typing_extensions.get_type_hints(type_, include_extras=True)
+    return _get_field_to_alias_name(annotations)
+
+
+def _get_alias_to_field_name(
+    field_to_hint: typing.Dict[str, typing.Any],
+) -> typing.Dict[str, str]:
+    aliases = {}
+    for field, hint in field_to_hint.items():
+        maybe_alias = _get_alias_from_type(hint)
+        if maybe_alias is not None:
+            aliases[maybe_alias] = field
+    return aliases
+
+
+def _get_field_to_alias_name(
+    field_to_hint: typing.Dict[str, typing.Any],
+) -> typing.Dict[str, str]:
+    aliases = {}
+    for field, hint in field_to_hint.items():
+        maybe_alias = _get_alias_from_type(hint)
+        if maybe_alias is not None:
+            aliases[field] = maybe_alias
+    return aliases
+
+
+def _get_alias_from_type(type_: typing.Any) -> typing.Optional[str]:
     maybe_annotated_type = _get_annotation(type_)
 
     if maybe_annotated_type is not None:
@@ -175,5 +258,15 @@ def _alias_key(key: str, type_: typing.Any) -> str:
         for annotation in annotations:
             if isinstance(annotation, FieldMetadata) and annotation.alias is not None:
                 return annotation.alias
+    return None
+
 
-    return key
+def _alias_key(
+    key: str,
+    type_: typing.Any,
+    direction: typing.Literal["read", "write"],
+    aliases_to_field_names: typing.Dict[str, str],
+) -> str:
+    if direction == "read":
+        return aliases_to_field_names.get(key, key)
+    return _get_alias_from_type(type_=type_) or key
diff --git a/seed/pydantic/server-sent-events/src/seed/server_sent_events/resources/completions/streamed_completion.py b/seed/pydantic/server-sent-events/src/seed/server_sent_events/resources/completions/streamed_completion.py
index 2a6089db912..1d8a2c11dd3 100644
--- a/seed/pydantic/server-sent-events/src/seed/server_sent_events/resources/completions/streamed_completion.py
+++ b/seed/pydantic/server-sent-events/src/seed/server_sent_events/resources/completions/streamed_completion.py
@@ -11,9 +11,7 @@ class StreamedCompletion(UniversalBaseModel):
     tokens: typing.Optional[int] = None
 
     if IS_PYDANTIC_V2:
-        model_config: typing.ClassVar[pydantic.ConfigDict] = pydantic.ConfigDict(
-            extra="allow"
-        )  # type: ignore # Pydantic v2
+        model_config: typing.ClassVar[pydantic.ConfigDict] = pydantic.ConfigDict(extra="allow")  # type: ignore # Pydantic v2
     else:
 
         class Config:
diff --git a/seed/python-sdk/server-sent-events/README.md b/seed/python-sdk/server-sent-events/README.md
index caa3e4e9608..2facc123618 100644
--- a/seed/python-sdk/server-sent-events/README.md
+++ b/seed/python-sdk/server-sent-events/README.md
@@ -1,6 +1,6 @@
 # Seed Python Library
 
-[![fern shield](https://img.shields.io/badge/%F0%9F%8C%BF-SDK%20generated%20by%20Fern-brightgreen)](https://github.com/fern-api/fern)
+[![fern shield](https://img.shields.io/badge/%F0%9F%8C%BF-Built%20with%20Fern-brightgreen)](https://buildwithfern.com?utm_source=github&utm_medium=github&utm_campaign=readme&utm_source=Seed%2FPython)
 [![pypi](https://img.shields.io/pypi/v/fern_server-sent-events)](https://pypi.python.org/pypi/fern_server-sent-events)
 
 The Seed Python library provides convenient access to the Seed API from Python.
@@ -11,6 +11,10 @@ The Seed Python library provides convenient access to the Seed API from Python.
 pip install fern_server-sent-events
 ```
 
+## Reference
+
+A full reference for this library is available [here](./reference.md).
+
 ## Usage
 
 Instantiate and use the client with the following:
@@ -102,7 +106,7 @@ A request is deemed retriable when any of the following HTTP status codes is ret
 Use the `max_retries` request option to configure this behavior.
 
 ```python
-client.completions.stream({
+client.completions.stream(request_options={
     "max_retries": 1
 })
 ```
@@ -122,7 +126,7 @@ client = SeedServerSentEvents(
 
 
 # Override timeout for a specific method
-client.completions.stream({
+client.completions.stream(request_options={
     "timeout_in_seconds": 1
 })
 ```
diff --git a/seed/python-sdk/server-sent-events/resolved-snippet-templates.md b/seed/python-sdk/server-sent-events/resolved-snippet-templates.md
new file mode 100644
index 00000000000..8f00e6ba3ba
--- /dev/null
+++ b/seed/python-sdk/server-sent-events/resolved-snippet-templates.md
@@ -0,0 +1,11 @@
+```python
+
+
+client = SeedServerSentEvents(base_url="https://yourhost.com/path/to/api", )        
+client.completions.stream(
+	query="string"
+)
+ 
+```                        
+
+
diff --git a/seed/python-sdk/server-sent-events/src/seed/core/__init__.py b/seed/python-sdk/server-sent-events/src/seed/core/__init__.py
index 5a0bee343d0..f03aecbfe18 100644
--- a/seed/python-sdk/server-sent-events/src/seed/core/__init__.py
+++ b/seed/python-sdk/server-sent-events/src/seed/core/__init__.py
@@ -3,14 +3,13 @@
 from .api_error import ApiError
 from .client_wrapper import AsyncClientWrapper, BaseClientWrapper, SyncClientWrapper
 from .datetime_utils import serialize_datetime
-from .file import File, convert_file_dict_to_httpx_tuples
+from .file import File, convert_file_dict_to_httpx_tuples, with_content_type
 from .http_client import AsyncHttpClient, HttpClient
 from .jsonable_encoder import jsonable_encoder
 from .pydantic_utilities import (
     IS_PYDANTIC_V2,
     UniversalBaseModel,
     UniversalRootModel,
-    deep_union_pydantic_dicts,
     parse_obj_as,
     universal_field_validator,
     universal_root_validator,
@@ -36,7 +35,6 @@
     "UniversalRootModel",
     "convert_and_respect_annotation_metadata",
     "convert_file_dict_to_httpx_tuples",
-    "deep_union_pydantic_dicts",
     "encode_query",
     "jsonable_encoder",
     "parse_obj_as",
@@ -45,4 +43,5 @@
     "universal_field_validator",
     "universal_root_validator",
     "update_forward_refs",
+    "with_content_type",
 ]
diff --git a/seed/python-sdk/server-sent-events/src/seed/core/client_wrapper.py b/seed/python-sdk/server-sent-events/src/seed/core/client_wrapper.py
index 314a74c13e8..302bb582845 100644
--- a/seed/python-sdk/server-sent-events/src/seed/core/client_wrapper.py
+++ b/seed/python-sdk/server-sent-events/src/seed/core/client_wrapper.py
@@ -31,9 +31,9 @@ def __init__(self, *, base_url: str, timeout: typing.Optional[float] = None, htt
         super().__init__(base_url=base_url, timeout=timeout)
         self.httpx_client = HttpClient(
             httpx_client=httpx_client,
-            base_headers=self.get_headers(),
-            base_timeout=self.get_timeout(),
-            base_url=self.get_base_url(),
+            base_headers=self.get_headers,
+            base_timeout=self.get_timeout,
+            base_url=self.get_base_url,
         )
 
 
@@ -42,7 +42,7 @@ def __init__(self, *, base_url: str, timeout: typing.Optional[float] = None, htt
         super().__init__(base_url=base_url, timeout=timeout)
         self.httpx_client = AsyncHttpClient(
             httpx_client=httpx_client,
-            base_headers=self.get_headers(),
-            base_timeout=self.get_timeout(),
-            base_url=self.get_base_url(),
+            base_headers=self.get_headers,
+            base_timeout=self.get_timeout,
+            base_url=self.get_base_url,
         )
diff --git a/seed/python-sdk/server-sent-events/src/seed/core/file.py b/seed/python-sdk/server-sent-events/src/seed/core/file.py
index 6e0f92bfcb1..b4cbba30f73 100644
--- a/seed/python-sdk/server-sent-events/src/seed/core/file.py
+++ b/seed/python-sdk/server-sent-events/src/seed/core/file.py
@@ -1,30 +1,30 @@
 # This file was auto-generated by Fern from our API Definition.
 
-import typing
+from typing import IO, Dict, List, Mapping, Optional, Tuple, Union, cast
 
 # File typing inspired by the flexibility of types within the httpx library
 # https://github.com/encode/httpx/blob/master/httpx/_types.py
-FileContent = typing.Union[typing.IO[bytes], bytes, str]
-File = typing.Union[
+FileContent = Union[IO[bytes], bytes, str]
+File = Union[
     # file (or bytes)
     FileContent,
     # (filename, file (or bytes))
-    typing.Tuple[typing.Optional[str], FileContent],
+    Tuple[Optional[str], FileContent],
     # (filename, file (or bytes), content_type)
-    typing.Tuple[typing.Optional[str], FileContent, typing.Optional[str]],
+    Tuple[Optional[str], FileContent, Optional[str]],
     # (filename, file (or bytes), content_type, headers)
-    typing.Tuple[
-        typing.Optional[str],
+    Tuple[
+        Optional[str],
         FileContent,
-        typing.Optional[str],
-        typing.Mapping[str, str],
+        Optional[str],
+        Mapping[str, str],
     ],
 ]
 
 
 def convert_file_dict_to_httpx_tuples(
-    d: typing.Dict[str, typing.Union[File, typing.List[File]]],
-) -> typing.List[typing.Tuple[str, File]]:
+    d: Dict[str, Union[File, List[File]]],
+) -> List[Tuple[str, File]]:
     """
     The format we use is a list of tuples, where the first element is the
     name of the file and the second is the file object. Typically HTTPX wants
@@ -41,3 +41,22 @@ def convert_file_dict_to_httpx_tuples(
         else:
             httpx_tuples.append((key, file_like))
     return httpx_tuples
+
+
+def with_content_type(*, file: File, content_type: str) -> File:
+    """ """
+    if isinstance(file, tuple):
+        if len(file) == 2:
+            filename, content = cast(Tuple[Optional[str], FileContent], file)  # type: ignore
+            return (filename, content, content_type)
+        elif len(file) == 3:
+            filename, content, _ = cast(Tuple[Optional[str], FileContent, Optional[str]], file)  # type: ignore
+            return (filename, content, content_type)
+        elif len(file) == 4:
+            filename, content, _, headers = cast(  # type: ignore
+                Tuple[Optional[str], FileContent, Optional[str], Mapping[str, str]], file
+            )
+            return (filename, content, content_type, headers)
+        else:
+            raise ValueError(f"Unexpected tuple length: {len(file)}")
+    return (None, file, content_type)
diff --git a/seed/python-sdk/server-sent-events/src/seed/core/http_client.py b/seed/python-sdk/server-sent-events/src/seed/core/http_client.py
index b07401b50eb..eb4e8943cec 100644
--- a/seed/python-sdk/server-sent-events/src/seed/core/http_client.py
+++ b/seed/python-sdk/server-sent-events/src/seed/core/http_client.py
@@ -152,9 +152,9 @@ def __init__(
         self,
         *,
         httpx_client: httpx.Client,
-        base_timeout: typing.Optional[float],
-        base_headers: typing.Dict[str, str],
-        base_url: typing.Optional[str] = None,
+        base_timeout: typing.Callable[[], typing.Optional[float]],
+        base_headers: typing.Callable[[], typing.Dict[str, str]],
+        base_url: typing.Optional[typing.Callable[[], str]] = None,
     ):
         self.base_url = base_url
         self.base_timeout = base_timeout
@@ -162,7 +162,10 @@ def __init__(
         self.httpx_client = httpx_client
 
     def get_base_url(self, maybe_base_url: typing.Optional[str]) -> str:
-        base_url = self.base_url if maybe_base_url is None else maybe_base_url
+        base_url = maybe_base_url
+        if self.base_url is not None and base_url is None:
+            base_url = self.base_url()
+
         if base_url is None:
             raise ValueError("A base_url is required to make this request, please provide one and try again.")
         return base_url
@@ -187,7 +190,7 @@ def request(
         timeout = (
             request_options.get("timeout_in_seconds")
             if request_options is not None and request_options.get("timeout_in_seconds") is not None
-            else self.base_timeout
+            else self.base_timeout()
         )
 
         json_body, data_body = get_request_body(json=json, data=data, request_options=request_options, omit=omit)
@@ -198,7 +201,7 @@ def request(
             headers=jsonable_encoder(
                 remove_none_from_dict(
                     {
-                        **self.base_headers,
+                        **self.base_headers(),
                         **(headers if headers is not None else {}),
                         **(request_options.get("additional_headers", {}) or {} if request_options is not None else {}),
                     }
@@ -224,7 +227,9 @@ def request(
             json=json_body,
             data=data_body,
             content=content,
-            files=convert_file_dict_to_httpx_tuples(remove_none_from_dict(files)) if files is not None else None,
+            files=convert_file_dict_to_httpx_tuples(remove_none_from_dict(files))
+            if (files is not None and files is not omit)
+            else None,
             timeout=timeout,
         )
 
@@ -269,7 +274,7 @@ def stream(
         timeout = (
             request_options.get("timeout_in_seconds")
             if request_options is not None and request_options.get("timeout_in_seconds") is not None
-            else self.base_timeout
+            else self.base_timeout()
         )
 
         json_body, data_body = get_request_body(json=json, data=data, request_options=request_options, omit=omit)
@@ -280,7 +285,7 @@ def stream(
             headers=jsonable_encoder(
                 remove_none_from_dict(
                     {
-                        **self.base_headers,
+                        **self.base_headers(),
                         **(headers if headers is not None else {}),
                         **(request_options.get("additional_headers", {}) if request_options is not None else {}),
                     }
@@ -306,7 +311,9 @@ def stream(
             json=json_body,
             data=data_body,
             content=content,
-            files=convert_file_dict_to_httpx_tuples(remove_none_from_dict(files)) if files is not None else None,
+            files=convert_file_dict_to_httpx_tuples(remove_none_from_dict(files))
+            if (files is not None and files is not omit)
+            else None,
             timeout=timeout,
         ) as stream:
             yield stream
@@ -317,9 +324,9 @@ def __init__(
         self,
         *,
         httpx_client: httpx.AsyncClient,
-        base_timeout: typing.Optional[float],
-        base_headers: typing.Dict[str, str],
-        base_url: typing.Optional[str] = None,
+        base_timeout: typing.Callable[[], typing.Optional[float]],
+        base_headers: typing.Callable[[], typing.Dict[str, str]],
+        base_url: typing.Optional[typing.Callable[[], str]] = None,
     ):
         self.base_url = base_url
         self.base_timeout = base_timeout
@@ -327,7 +334,10 @@ def __init__(
         self.httpx_client = httpx_client
 
     def get_base_url(self, maybe_base_url: typing.Optional[str]) -> str:
-        base_url = self.base_url if maybe_base_url is None else maybe_base_url
+        base_url = maybe_base_url
+        if self.base_url is not None and base_url is None:
+            base_url = self.base_url()
+
         if base_url is None:
             raise ValueError("A base_url is required to make this request, please provide one and try again.")
         return base_url
@@ -352,7 +362,7 @@ async def request(
         timeout = (
             request_options.get("timeout_in_seconds")
             if request_options is not None and request_options.get("timeout_in_seconds") is not None
-            else self.base_timeout
+            else self.base_timeout()
         )
 
         json_body, data_body = get_request_body(json=json, data=data, request_options=request_options, omit=omit)
@@ -364,7 +374,7 @@ async def request(
             headers=jsonable_encoder(
                 remove_none_from_dict(
                     {
-                        **self.base_headers,
+                        **self.base_headers(),
                         **(headers if headers is not None else {}),
                         **(request_options.get("additional_headers", {}) or {} if request_options is not None else {}),
                     }
@@ -434,7 +444,7 @@ async def stream(
         timeout = (
             request_options.get("timeout_in_seconds")
             if request_options is not None and request_options.get("timeout_in_seconds") is not None
-            else self.base_timeout
+            else self.base_timeout()
         )
 
         json_body, data_body = get_request_body(json=json, data=data, request_options=request_options, omit=omit)
@@ -445,7 +455,7 @@ async def stream(
             headers=jsonable_encoder(
                 remove_none_from_dict(
                     {
-                        **self.base_headers,
+                        **self.base_headers(),
                         **(headers if headers is not None else {}),
                         **(request_options.get("additional_headers", {}) if request_options is not None else {}),
                     }
diff --git a/seed/python-sdk/server-sent-events/src/seed/core/pydantic_utilities.py b/seed/python-sdk/server-sent-events/src/seed/core/pydantic_utilities.py
index a14ef4c0b90..ee8f0e4105f 100644
--- a/seed/python-sdk/server-sent-events/src/seed/core/pydantic_utilities.py
+++ b/seed/python-sdk/server-sent-events/src/seed/core/pydantic_utilities.py
@@ -4,11 +4,13 @@
 import datetime as dt
 import typing
 from collections import defaultdict
-from functools import wraps
+
+import typing_extensions
 
 import pydantic
 
 from .datetime_utils import serialize_datetime
+from .serialization import convert_and_respect_annotation_metadata
 
 IS_PYDANTIC_V2 = pydantic.VERSION.startswith("2.")
 
@@ -54,25 +56,13 @@
 Model = typing.TypeVar("Model", bound=pydantic.BaseModel)
 
 
-def deep_union_pydantic_dicts(
-    source: typing.Dict[str, typing.Any], destination: typing.Dict[str, typing.Any]
-) -> typing.Dict[str, typing.Any]:
-    for key, value in source.items():
-        if isinstance(value, dict):
-            node = destination.setdefault(key, {})
-            deep_union_pydantic_dicts(value, node)
-        else:
-            destination[key] = value
-
-    return destination
-
-
 def parse_obj_as(type_: typing.Type[T], object_: typing.Any) -> T:
+    dealiased_object = convert_and_respect_annotation_metadata(object_=object_, annotation=type_, direction="read")
     if IS_PYDANTIC_V2:
         adapter = pydantic.TypeAdapter(type_)  # type: ignore # Pydantic v2
-        return adapter.validate_python(object_)
+        return adapter.validate_python(dealiased_object)
     else:
-        return pydantic.parse_obj_as(type_, object_)
+        return pydantic.parse_obj_as(type_, dealiased_object)
 
 
 def to_jsonable_with_fallback(
@@ -87,11 +77,40 @@ def to_jsonable_with_fallback(
 
 
 class UniversalBaseModel(pydantic.BaseModel):
-    class Config:
-        populate_by_name = True
-        smart_union = True
-        allow_population_by_field_name = True
-        json_encoders = {dt.datetime: serialize_datetime}
+    if IS_PYDANTIC_V2:
+        model_config: typing.ClassVar[pydantic.ConfigDict] = pydantic.ConfigDict(
+            # Allow fields begining with `model_` to be used in the model
+            protected_namespaces=(),
+        )  # type: ignore # Pydantic v2
+
+        @pydantic.model_serializer(mode="wrap", when_used="json")  # type: ignore # Pydantic v2
+        def serialize_model(self, handler: pydantic.SerializerFunctionWrapHandler) -> typing.Any:  # type: ignore # Pydantic v2
+            serialized = handler(self)
+            data = {k: serialize_datetime(v) if isinstance(v, dt.datetime) else v for k, v in serialized.items()}
+            return data
+
+    else:
+
+        class Config:
+            smart_union = True
+            json_encoders = {dt.datetime: serialize_datetime}
+
+    @classmethod
+    def model_construct(
+        cls: typing.Type["Model"], _fields_set: typing.Optional[typing.Set[str]] = None, **values: typing.Any
+    ) -> "Model":
+        dealiased_object = convert_and_respect_annotation_metadata(object_=values, annotation=cls, direction="read")
+        return cls.construct(_fields_set, **dealiased_object)
+
+    @classmethod
+    def construct(
+        cls: typing.Type["Model"], _fields_set: typing.Optional[typing.Set[str]] = None, **values: typing.Any
+    ) -> "Model":
+        dealiased_object = convert_and_respect_annotation_metadata(object_=values, annotation=cls, direction="read")
+        if IS_PYDANTIC_V2:
+            return super().model_construct(_fields_set, **dealiased_object)  # type: ignore # Pydantic v2
+        else:
+            return super().construct(_fields_set, **dealiased_object)
 
     def json(self, **kwargs: typing.Any) -> str:
         kwargs_with_defaults: typing.Any = {
@@ -105,38 +124,103 @@ def json(self, **kwargs: typing.Any) -> str:
             return super().json(**kwargs_with_defaults)
 
     def dict(self, **kwargs: typing.Any) -> typing.Dict[str, typing.Any]:
-        kwargs_with_defaults_exclude_unset: typing.Any = {
-            "by_alias": True,
-            "exclude_unset": True,
-            **kwargs,
-        }
-        kwargs_with_defaults_exclude_none: typing.Any = {
-            "by_alias": True,
-            "exclude_none": True,
-            **kwargs,
-        }
-
+        """
+        Override the default dict method to `exclude_unset` by default. This function patches
+        `exclude_unset` to work include fields within non-None default values.
+        """
+        # Note: the logic here is multi-plexed given the levers exposed in Pydantic V1 vs V2
+        # Pydantic V1's .dict can be extremely slow, so we do not want to call it twice.
+        #
+        # We'd ideally do the same for Pydantic V2, but it shells out to a library to serialize models
+        # that we have less control over, and this is less intrusive than custom serializers for now.
         if IS_PYDANTIC_V2:
-            return deep_union_pydantic_dicts(
+            kwargs_with_defaults_exclude_unset: typing.Any = {
+                **kwargs,
+                "by_alias": True,
+                "exclude_unset": True,
+                "exclude_none": False,
+            }
+            kwargs_with_defaults_exclude_none: typing.Any = {
+                **kwargs,
+                "by_alias": True,
+                "exclude_none": True,
+                "exclude_unset": False,
+            }
+            dict_dump = deep_union_pydantic_dicts(
                 super().model_dump(**kwargs_with_defaults_exclude_unset),  # type: ignore # Pydantic v2
                 super().model_dump(**kwargs_with_defaults_exclude_none),  # type: ignore # Pydantic v2
             )
+
         else:
-            return deep_union_pydantic_dicts(
-                super().dict(**kwargs_with_defaults_exclude_unset),
-                super().dict(**kwargs_with_defaults_exclude_none),
-            )
+            _fields_set = self.__fields_set__.copy()
+
+            fields = _get_model_fields(self.__class__)
+            for name, field in fields.items():
+                if name not in _fields_set:
+                    default = _get_field_default(field)
+
+                    # If the default values are non-null act like they've been set
+                    # This effectively allows exclude_unset to work like exclude_none where
+                    # the latter passes through intentionally set none values.
+                    if default is not None or ("exclude_unset" in kwargs and not kwargs["exclude_unset"]):
+                        _fields_set.add(name)
+
+                        if default is not None:
+                            self.__fields_set__.add(name)
+
+            kwargs_with_defaults_exclude_unset_include_fields: typing.Any = {
+                "by_alias": True,
+                "exclude_unset": True,
+                "include": _fields_set,
+                **kwargs,
+            }
+
+            dict_dump = super().dict(**kwargs_with_defaults_exclude_unset_include_fields)
+
+        return convert_and_respect_annotation_metadata(object_=dict_dump, annotation=self.__class__, direction="write")
+
+
+def _union_list_of_pydantic_dicts(
+    source: typing.List[typing.Any], destination: typing.List[typing.Any]
+) -> typing.List[typing.Any]:
+    converted_list: typing.List[typing.Any] = []
+    for i, item in enumerate(source):
+        destination_value = destination[i]  # type: ignore
+        if isinstance(item, dict):
+            converted_list.append(deep_union_pydantic_dicts(item, destination_value))
+        elif isinstance(item, list):
+            converted_list.append(_union_list_of_pydantic_dicts(item, destination_value))
+        else:
+            converted_list.append(item)
+    return converted_list
+
+
+def deep_union_pydantic_dicts(
+    source: typing.Dict[str, typing.Any], destination: typing.Dict[str, typing.Any]
+) -> typing.Dict[str, typing.Any]:
+    for key, value in source.items():
+        node = destination.setdefault(key, {})
+        if isinstance(value, dict):
+            deep_union_pydantic_dicts(value, node)
+        # Note: we do not do this same processing for sets given we do not have sets of models
+        # and given the sets are unordered, the processing of the set and matching objects would
+        # be non-trivial.
+        elif isinstance(value, list):
+            destination[key] = _union_list_of_pydantic_dicts(value, node)
+        else:
+            destination[key] = value
+
+    return destination
 
 
-UniversalRootModel: typing.Type[pydantic.BaseModel]
 if IS_PYDANTIC_V2:
 
     class V2RootModel(UniversalBaseModel, pydantic.RootModel):  # type: ignore # Pydantic v2
         pass
 
-    UniversalRootModel = V2RootModel
+    UniversalRootModel: typing_extensions.TypeAlias = V2RootModel  # type: ignore
 else:
-    UniversalRootModel = UniversalBaseModel
+    UniversalRootModel: typing_extensions.TypeAlias = UniversalBaseModel  # type: ignore
 
 
 def encode_by_type(o: typing.Any) -> typing.Any:
@@ -153,11 +237,11 @@ def encode_by_type(o: typing.Any) -> typing.Any:
             return encoder(o)
 
 
-def update_forward_refs(model: typing.Type["Model"]) -> None:
+def update_forward_refs(model: typing.Type["Model"], **localns: typing.Any) -> None:
     if IS_PYDANTIC_V2:
         model.model_rebuild(raise_errors=False)  # type: ignore # Pydantic v2
     else:
-        model.update_forward_refs()
+        model.update_forward_refs(**localns)
 
 
 # Mirrors Pydantic's internal typing
@@ -168,33 +252,45 @@ def universal_root_validator(
     pre: bool = False,
 ) -> typing.Callable[[AnyCallable], AnyCallable]:
     def decorator(func: AnyCallable) -> AnyCallable:
-        @wraps(func)
-        def validate(*args: typing.Any, **kwargs: typing.Any) -> AnyCallable:
-            if IS_PYDANTIC_V2:
-                wrapped_func = pydantic.model_validator("before" if pre else "after")(  # type: ignore # Pydantic v2
-                    func
-                )
-            else:
-                wrapped_func = pydantic.root_validator(pre=pre)(func)  # type: ignore # Pydantic v1
-
-            return wrapped_func(*args, **kwargs)  # type: ignore # Pydantic v2
-
-        return validate
+        if IS_PYDANTIC_V2:
+            return pydantic.model_validator(mode="before" if pre else "after")(func)  # type: ignore # Pydantic v2
+        else:
+            return pydantic.root_validator(pre=pre)(func)  # type: ignore # Pydantic v1
 
     return decorator
 
 
 def universal_field_validator(field_name: str, pre: bool = False) -> typing.Callable[[AnyCallable], AnyCallable]:
     def decorator(func: AnyCallable) -> AnyCallable:
-        @wraps(func)
-        def validate(*args: typing.Any, **kwargs: typing.Any) -> AnyCallable:
-            if IS_PYDANTIC_V2:
-                wrapped_func = pydantic.field_validator(field_name, mode="before" if pre else "after")(func)  # type: ignore # Pydantic v2
-            else:
-                wrapped_func = pydantic.validator(field_name, pre=pre)(func)  # type: ignore # Pydantic v1
+        if IS_PYDANTIC_V2:
+            return pydantic.field_validator(field_name, mode="before" if pre else "after")(func)  # type: ignore # Pydantic v2
+        else:
+            return pydantic.validator(field_name, pre=pre)(func)  # type: ignore # Pydantic v1
 
-            return wrapped_func(*args, **kwargs)
+    return decorator
 
-        return validate
 
-    return decorator
+PydanticField = typing.Union[ModelField, pydantic.fields.FieldInfo]
+
+
+def _get_model_fields(
+    model: typing.Type["Model"],
+) -> typing.Mapping[str, PydanticField]:
+    if IS_PYDANTIC_V2:
+        return model.model_fields  # type: ignore # Pydantic v2
+    else:
+        return model.__fields__  # type: ignore # Pydantic v1
+
+
+def _get_field_default(field: PydanticField) -> typing.Any:
+    try:
+        value = field.get_default()  # type: ignore # Pydantic < v1.10.15
+    except:
+        value = field.default
+    if IS_PYDANTIC_V2:
+        from pydantic_core import PydanticUndefined
+
+        if value == PydanticUndefined:
+            return None
+        return value
+    return value
diff --git a/seed/python-sdk/server-sent-events/src/seed/core/query_encoder.py b/seed/python-sdk/server-sent-events/src/seed/core/query_encoder.py
index 24076d72ee9..3183001d404 100644
--- a/seed/python-sdk/server-sent-events/src/seed/core/query_encoder.py
+++ b/seed/python-sdk/server-sent-events/src/seed/core/query_encoder.py
@@ -1,33 +1,58 @@
 # This file was auto-generated by Fern from our API Definition.
 
-from collections import ChainMap
-from typing import Any, Dict, Optional
+from typing import Any, Dict, List, Optional, Tuple
 
 import pydantic
 
 
 # Flattens dicts to be of the form {"key[subkey][subkey2]": value} where value is not a dict
-def traverse_query_dict(dict_flat: Dict[str, Any], key_prefix: Optional[str] = None) -> Dict[str, Any]:
-    result = {}
+def traverse_query_dict(dict_flat: Dict[str, Any], key_prefix: Optional[str] = None) -> List[Tuple[str, Any]]:
+    result = []
     for k, v in dict_flat.items():
         key = f"{key_prefix}[{k}]" if key_prefix is not None else k
         if isinstance(v, dict):
-            result.update(traverse_query_dict(v, key))
+            result.extend(traverse_query_dict(v, key))
+        elif isinstance(v, list):
+            for arr_v in v:
+                if isinstance(arr_v, dict):
+                    result.extend(traverse_query_dict(arr_v, key))
+                else:
+                    result.append((key, arr_v))
         else:
-            result[key] = v
+            result.append((key, v))
     return result
 
 
-def single_query_encoder(query_key: str, query_value: Any) -> Dict[str, Any]:
+def single_query_encoder(query_key: str, query_value: Any) -> List[Tuple[str, Any]]:
     if isinstance(query_value, pydantic.BaseModel) or isinstance(query_value, dict):
         if isinstance(query_value, pydantic.BaseModel):
             obj_dict = query_value.dict(by_alias=True)
         else:
             obj_dict = query_value
         return traverse_query_dict(obj_dict, query_key)
+    elif isinstance(query_value, list):
+        encoded_values: List[Tuple[str, Any]] = []
+        for value in query_value:
+            if isinstance(value, pydantic.BaseModel) or isinstance(value, dict):
+                if isinstance(value, pydantic.BaseModel):
+                    obj_dict = value.dict(by_alias=True)
+                elif isinstance(value, dict):
+                    obj_dict = value
 
-    return {query_key: query_value}
+                encoded_values.extend(single_query_encoder(query_key, obj_dict))
+            else:
+                encoded_values.append((query_key, value))
 
+        return encoded_values
 
-def encode_query(query: Optional[Dict[str, Any]]) -> Optional[Dict[str, Any]]:
-    return dict(ChainMap(*[single_query_encoder(k, v) for k, v in query.items()])) if query is not None else None
+    return [(query_key, query_value)]
+
+
+def encode_query(query: Optional[Dict[str, Any]]) -> Optional[List[Tuple[str, Any]]]:
+    if query is None:
+        return None
+
+    encoded_query = []
+    for k, v in query.items():
+        encoded_query.extend(single_query_encoder(k, v))
+    return encoded_query
diff --git a/seed/python-sdk/server-sent-events/src/seed/core/serialization.py b/seed/python-sdk/server-sent-events/src/seed/core/serialization.py
index 36180ac858f..cb5dcbf93a9 100644
--- a/seed/python-sdk/server-sent-events/src/seed/core/serialization.py
+++ b/seed/python-sdk/server-sent-events/src/seed/core/serialization.py
@@ -1,10 +1,13 @@
 # This file was auto-generated by Fern from our API Definition.
 
 import collections
+import inspect
 import typing
 
 import typing_extensions
 
+import pydantic
+
 
 class FieldMetadata:
     """
@@ -29,6 +32,7 @@ def convert_and_respect_annotation_metadata(
     object_: typing.Any,
     annotation: typing.Any,
     inner_type: typing.Optional[typing.Any] = None,
+    direction: typing.Literal["read", "write"],
 ) -> typing.Any:
     """
     Respect the metadata annotations on a field, such as aliasing. This function effectively
@@ -56,44 +60,77 @@ def convert_and_respect_annotation_metadata(
         inner_type = annotation
 
     clean_type = _remove_annotations(inner_type)
+    # Pydantic models
+    if (
+        inspect.isclass(clean_type)
+        and issubclass(clean_type, pydantic.BaseModel)
+        and isinstance(object_, typing.Mapping)
+    ):
+        return _convert_mapping(object_, clean_type, direction)
+    # TypedDicts
     if typing_extensions.is_typeddict(clean_type) and isinstance(object_, typing.Mapping):
-        return _convert_typeddict(object_, clean_type)
+        return _convert_mapping(object_, clean_type, direction)
 
     if (
-        # If you're iterating on a string, do not bother to coerce it to a sequence.
-        (not isinstance(object_, str))
-        and (
-            (
-                (
-                    typing_extensions.get_origin(clean_type) == typing.List
-                    or typing_extensions.get_origin(clean_type) == list
-                    or clean_type == typing.List
-                )
-                and isinstance(object_, typing.List)
+        typing_extensions.get_origin(clean_type) == typing.Dict
+        or typing_extensions.get_origin(clean_type) == dict
+        or clean_type == typing.Dict
+    ) and isinstance(object_, typing.Dict):
+        key_type = typing_extensions.get_args(clean_type)[0]
+        value_type = typing_extensions.get_args(clean_type)[1]
+
+        return {
+            key: convert_and_respect_annotation_metadata(
+                object_=value,
+                annotation=annotation,
+                inner_type=value_type,
+                direction=direction,
             )
-            or (
-                (
-                    typing_extensions.get_origin(clean_type) == typing.Set
-                    or typing_extensions.get_origin(clean_type) == set
-                    or clean_type == typing.Set
+            for key, value in object_.items()
+        }
+
+    # If you're iterating on a string, do not bother to coerce it to a sequence.
+    if not isinstance(object_, str):
+        if (
+            typing_extensions.get_origin(clean_type) == typing.Set
+            or typing_extensions.get_origin(clean_type) == set
+            or clean_type == typing.Set
+        ) and isinstance(object_, typing.Set):
+            inner_type = typing_extensions.get_args(clean_type)[0]
+            return {
+                convert_and_respect_annotation_metadata(
+                    object_=item,
+                    annotation=annotation,
+                    inner_type=inner_type,
+                    direction=direction,
                 )
-                and isinstance(object_, typing.Set)
+                for item in object_
+            }
+        elif (
+            (
+                typing_extensions.get_origin(clean_type) == typing.List
+                or typing_extensions.get_origin(clean_type) == list
+                or clean_type == typing.List
             )
-            or (
-                (
-                    typing_extensions.get_origin(clean_type) == typing.Sequence
-                    or typing_extensions.get_origin(clean_type) == collections.abc.Sequence
-                    or clean_type == typing.Sequence
-                )
-                and isinstance(object_, typing.Sequence)
+            and isinstance(object_, typing.List)
+        ) or (
+            (
+                typing_extensions.get_origin(clean_type) == typing.Sequence
+                or typing_extensions.get_origin(clean_type) == collections.abc.Sequence
+                or clean_type == typing.Sequence
             )
-        )
-    ):
-        inner_type = typing_extensions.get_args(clean_type)[0]
-        return [
-            convert_and_respect_annotation_metadata(object_=item, annotation=annotation, inner_type=inner_type)
-            for item in object_
-        ]
+            and isinstance(object_, typing.Sequence)
+        ):
+            inner_type = typing_extensions.get_args(clean_type)[0]
+            return [
+                convert_and_respect_annotation_metadata(
+                    object_=item,
+                    annotation=annotation,
+                    inner_type=inner_type,
+                    direction=direction,
+                )
+                for item in object_
+            ]
 
     if typing_extensions.get_origin(clean_type) == typing.Union:
         # We should be able to ~relatively~ safely try to convert keys against all
@@ -101,7 +138,12 @@ def convert_and_respect_annotation_metadata(
         # of the same name to a different name from another member
         # Or if another member aliases a field of the same name that another member does not.
         for member in typing_extensions.get_args(clean_type):
-            object_ = convert_and_respect_annotation_metadata(object_=object_, annotation=annotation, inner_type=member)
+            object_ = convert_and_respect_annotation_metadata(
+                object_=object_,
+                annotation=annotation,
+                inner_type=member,
+                direction=direction,
+            )
         return object_
 
     annotated_type = _get_annotation(annotation)
@@ -113,16 +155,34 @@ def convert_and_respect_annotation_metadata(
     return object_
 
 
-def _convert_typeddict(object_: typing.Mapping[str, object], expected_type: typing.Any) -> typing.Mapping[str, object]:
+def _convert_mapping(
+    object_: typing.Mapping[str, object],
+    expected_type: typing.Any,
+    direction: typing.Literal["read", "write"],
+) -> typing.Mapping[str, object]:
     converted_object: typing.Dict[str, object] = {}
     annotations = typing_extensions.get_type_hints(expected_type, include_extras=True)
+    aliases_to_field_names = _get_alias_to_field_name(annotations)
     for key, value in object_.items():
-        type_ = annotations.get(key)
+        if direction == "read" and key in aliases_to_field_names:
+            dealiased_key = aliases_to_field_names.get(key)
+            if dealiased_key is not None:
+                type_ = annotations.get(dealiased_key)
+        else:
+            type_ = annotations.get(key)
+        # Note you can't get the annotation by the field name if you're in read mode, so you must check the aliases map
+        #
+        # So this is effectively saying if we're in write mode, and we don't have a type, or if we're in read mode and we don't have an alias
+        # then we can just pass the value through as is
         if type_ is None:
             converted_object[key] = value
+        elif direction == "read" and key not in aliases_to_field_names:
+            converted_object[key] = convert_and_respect_annotation_metadata(
+                object_=value, annotation=type_, direction=direction
+            )
         else:
-            converted_object[_alias_key(key, type_)] = convert_and_respect_annotation_metadata(
-                object_=value, annotation=type_
+            converted_object[_alias_key(key, type_, direction, aliases_to_field_names)] = (
+                convert_and_respect_annotation_metadata(object_=value, annotation=type_, direction=direction)
             )
     return converted_object
 
@@ -156,7 +216,39 @@ def _remove_annotations(type_: typing.Any) -> typing.Any:
     return type_
 
 
-def _alias_key(key: str, type_: typing.Any) -> str:
+def get_alias_to_field_mapping(type_: typing.Any) -> typing.Dict[str, str]:
+    annotations = typing_extensions.get_type_hints(type_, include_extras=True)
+    return _get_alias_to_field_name(annotations)
+
+
+def get_field_to_alias_mapping(type_: typing.Any) -> typing.Dict[str, str]:
+    annotations = typing_extensions.get_type_hints(type_, include_extras=True)
+    return _get_field_to_alias_name(annotations)
+
+
+def _get_alias_to_field_name(
+    field_to_hint: typing.Dict[str, typing.Any],
+) -> typing.Dict[str, str]:
+    aliases = {}
+    for field, hint in field_to_hint.items():
+        maybe_alias = _get_alias_from_type(hint)
+        if maybe_alias is not None:
+            aliases[maybe_alias] = field
+    return aliases
+
+
+def _get_field_to_alias_name(
+    field_to_hint: typing.Dict[str, typing.Any],
+) -> typing.Dict[str, str]:
+    aliases = {}
+    for field, hint in field_to_hint.items():
+        maybe_alias = _get_alias_from_type(hint)
+        if maybe_alias is not None:
+            aliases[field] = maybe_alias
+    return aliases
+
+
+def _get_alias_from_type(type_: typing.Any) -> typing.Optional[str]:
     maybe_annotated_type = _get_annotation(type_)
 
     if maybe_annotated_type is not None:
@@ -166,5 +258,15 @@ def _alias_key(key: str, type_: typing.Any) -> str:
         for annotation in annotations:
             if isinstance(annotation, FieldMetadata) and annotation.alias is not None:
                 return annotation.alias
+    return None
+
 
-    return key
+def _alias_key(
+    key: str,
+    type_: typing.Any,
+    direction: typing.Literal["read", "write"],
+    aliases_to_field_names: typing.Dict[str, str],
+) -> str:
+    if direction == "read":
+        return aliases_to_field_names.get(key, key)
+    return _get_alias_from_type(type_=type_) or key
diff --git a/seed/python-sdk/server-sent-events/tests/utils/assets/models/circle.py b/seed/python-sdk/server-sent-events/tests/utils/assets/models/circle.py
index 74ecf38c308..6522dc58c5a 100644
--- a/seed/python-sdk/server-sent-events/tests/utils/assets/models/circle.py
+++ b/seed/python-sdk/server-sent-events/tests/utils/assets/models/circle.py
@@ -3,7 +3,7 @@
 # This file was auto-generated by Fern from our API Definition.
 
 import typing_extensions
-
+import typing_extensions
 from seed.core.serialization import FieldMetadata
 
 
diff --git a/seed/python-sdk/server-sent-events/tests/utils/assets/models/object_with_defaults.py b/seed/python-sdk/server-sent-events/tests/utils/assets/models/object_with_defaults.py
index a977b1d2aa1..ef14f7b2c9d 100644
--- a/seed/python-sdk/server-sent-events/tests/utils/assets/models/object_with_defaults.py
+++ b/seed/python-sdk/server-sent-events/tests/utils/assets/models/object_with_defaults.py
@@ -3,6 +3,7 @@
 # This file was auto-generated by Fern from our API Definition.
 
 import typing_extensions
+import typing_extensions
 
 
 class ObjectWithDefaultsParams(typing_extensions.TypedDict):
diff --git a/seed/python-sdk/server-sent-events/tests/utils/assets/models/object_with_optional_field.py b/seed/python-sdk/server-sent-events/tests/utils/assets/models/object_with_optional_field.py
index 4086c2356b1..fc5a379b967 100644
--- a/seed/python-sdk/server-sent-events/tests/utils/assets/models/object_with_optional_field.py
+++ b/seed/python-sdk/server-sent-events/tests/utils/assets/models/object_with_optional_field.py
@@ -2,13 +2,12 @@
 
 # This file was auto-generated by Fern from our API Definition.
 
-import datetime as dt
+import typing_extensions
 import typing
-import uuid
-
 import typing_extensions
-
 from seed.core.serialization import FieldMetadata
+import datetime as dt
+import uuid
 from .color import Color
 from .shape import ShapeParams
 from .undiscriminated_shape import UndiscriminatedShapeParams
@@ -32,4 +31,4 @@ class ObjectWithOptionalFieldParams(typing_extensions.TypedDict):
     union: typing_extensions.NotRequired[ShapeParams]
     second_union: typing_extensions.NotRequired[ShapeParams]
     undiscriminated_union: typing_extensions.NotRequired[UndiscriminatedShapeParams]
-    any: typing.Any
+    any: typing.Optional[typing.Any]
diff --git a/seed/python-sdk/server-sent-events/tests/utils/assets/models/shape.py b/seed/python-sdk/server-sent-events/tests/utils/assets/models/shape.py
index 7e70010a251..ae113ae0609 100644
--- a/seed/python-sdk/server-sent-events/tests/utils/assets/models/shape.py
+++ b/seed/python-sdk/server-sent-events/tests/utils/assets/models/shape.py
@@ -3,11 +3,9 @@
 # This file was auto-generated by Fern from our API Definition.
 
 from __future__ import annotations
-
-import typing
-
 import typing_extensions
-
+import typing_extensions
+import typing
 from seed.core.serialization import FieldMetadata
 
 
diff --git a/seed/python-sdk/server-sent-events/tests/utils/assets/models/square.py b/seed/python-sdk/server-sent-events/tests/utils/assets/models/square.py
index 71c7d25fd4a..7f6f79a3ddc 100644
--- a/seed/python-sdk/server-sent-events/tests/utils/assets/models/square.py
+++ b/seed/python-sdk/server-sent-events/tests/utils/assets/models/square.py
@@ -3,7 +3,7 @@
 # This file was auto-generated by Fern from our API Definition.
 
 import typing_extensions
-
+import typing_extensions
 from seed.core.serialization import FieldMetadata
 
 
diff --git a/seed/python-sdk/server-sent-events/tests/utils/assets/models/undiscriminated_shape.py b/seed/python-sdk/server-sent-events/tests/utils/assets/models/undiscriminated_shape.py
index 99f12b300d1..68876a23c38 100644
--- a/seed/python-sdk/server-sent-events/tests/utils/assets/models/undiscriminated_shape.py
+++ b/seed/python-sdk/server-sent-events/tests/utils/assets/models/undiscriminated_shape.py
@@ -3,7 +3,6 @@
 # This file was auto-generated by Fern from our API Definition.
 
 import typing
-
 from .circle import CircleParams
 from .square import SquareParams
 
diff --git a/seed/python-sdk/server-sent-events/tests/utils/test_query_encoding.py b/seed/python-sdk/server-sent-events/tests/utils/test_query_encoding.py
index 24a165a48ca..e075394a502 100644
--- a/seed/python-sdk/server-sent-events/tests/utils/test_query_encoding.py
+++ b/seed/python-sdk/server-sent-events/tests/utils/test_query_encoding.py
@@ -4,14 +4,32 @@
 from seed.core.query_encoder import encode_query
 
 
-def test_query_encoding() -> None:
-    assert encode_query({"hello world": "hello world"}) == {"hello world": "hello world"}
-    assert encode_query({"hello_world": {"hello": "world"}}) == {"hello_world[hello]": "world"}
-    assert encode_query({"hello_world": {"hello": {"world": "today"}, "test": "this"}, "hi": "there"}) == {
-        "hello_world[hello][world]": "today",
-        "hello_world[test]": "this",
-        "hi": "there",
-    }
+def test_query_encoding_deep_objects() -> None:
+    assert encode_query({"hello world": "hello world"}) == [("hello world", "hello world")]
+    assert encode_query({"hello_world": {"hello": "world"}}) == [("hello_world[hello]", "world")]
+    assert encode_query({"hello_world": {"hello": {"world": "today"}, "test": "this"}, "hi": "there"}) == [
+        ("hello_world[hello][world]", "today"),
+        ("hello_world[test]", "this"),
+        ("hi", "there"),
+    ]
+
+
+def test_query_encoding_deep_object_arrays() -> None:
+    assert encode_query({"objects": [{"key": "hello", "value": "world"}, {"key": "foo", "value": "bar"}]}) == [
+        ("objects[key]", "hello"),
+        ("objects[value]", "world"),
+        ("objects[key]", "foo"),
+        ("objects[value]", "bar"),
+    ]
+    assert encode_query(
+        {"users": [{"name": "string", "tags": ["string"]}, {"name": "string2", "tags": ["string2", "string3"]}]}
+    ) == [
+        ("users[name]", "string"),
+        ("users[tags]", "string"),
+        ("users[name]", "string2"),
+        ("users[tags]", "string2"),
+        ("users[tags]", "string3"),
+    ]
 
 
 def test_encode_query_with_none() -> None:
diff --git a/seed/python-sdk/server-sent-events/tests/utils/test_serialization.py b/seed/python-sdk/server-sent-events/tests/utils/test_serialization.py
index ca93a724b58..dd74836366c 100644
--- a/seed/python-sdk/server-sent-events/tests/utils/test_serialization.py
+++ b/seed/python-sdk/server-sent-events/tests/utils/test_serialization.py
@@ -18,7 +18,9 @@ def test_convert_and_respect_annotation_metadata() -> None:
         "literal": "lit_one",
         "any": "any",
     }
-    converted = convert_and_respect_annotation_metadata(object_=data, annotation=ObjectWithOptionalFieldParams)
+    converted = convert_and_respect_annotation_metadata(
+        object_=data, annotation=ObjectWithOptionalFieldParams, direction="write"
+    )
     assert converted == {"string": "string", "long": 12345, "bool": True, "literal": "lit_one", "any": "any"}
 
 
@@ -27,7 +29,9 @@ def test_convert_and_respect_annotation_metadata_in_list() -> None:
         {"string": "string", "long_": 12345, "bool_": True, "literal": "lit_one", "any": "any"},
         {"string": "another string", "long_": 67890, "list_": [], "literal": "lit_one", "any": "any"},
     ]
-    converted = convert_and_respect_annotation_metadata(object_=data, annotation=List[ObjectWithOptionalFieldParams])
+    converted = convert_and_respect_annotation_metadata(
+        object_=data, annotation=List[ObjectWithOptionalFieldParams], direction="write"
+    )
 
     assert converted == [
         {"string": "string", "long": 12345, "bool": True, "literal": "lit_one", "any": "any"},
@@ -43,7 +47,9 @@ def test_convert_and_respect_annotation_metadata_in_nested_object() -> None:
         "literal": "lit_one",
         "any": "any",
     }
-    converted = convert_and_respect_annotation_metadata(object_=data, annotation=ObjectWithOptionalFieldParams)
+    converted = convert_and_respect_annotation_metadata(
+        object_=data, annotation=ObjectWithOptionalFieldParams, direction="write"
+    )
 
     assert converted == {
         "string": "string",
@@ -55,12 +61,12 @@ def test_convert_and_respect_annotation_metadata_in_nested_object() -> None:
 
 
 def test_convert_and_respect_annotation_metadata_in_union() -> None:
-    converted = convert_and_respect_annotation_metadata(object_=UNION_TEST, annotation=ShapeParams)
+    converted = convert_and_respect_annotation_metadata(object_=UNION_TEST, annotation=ShapeParams, direction="write")
 
     assert converted == UNION_TEST_CONVERTED
 
 
 def test_convert_and_respect_annotation_metadata_with_empty_object() -> None:
     data: Any = {}
-    converted = convert_and_respect_annotation_metadata(object_=data, annotation=ShapeParams)
+    converted = convert_and_respect_annotation_metadata(object_=data, annotation=ShapeParams, direction="write")
     assert converted == data
diff --git a/seed/ruby-sdk/server-sent-events/fern_server_sent_events.gemspec b/seed/ruby-sdk/server-sent-events/fern_server_sent_events.gemspec
index 7510aaeef63..0cc0ed0d52f 100644
--- a/seed/ruby-sdk/server-sent-events/fern_server_sent_events.gemspec
+++ b/seed/ruby-sdk/server-sent-events/fern_server_sent_events.gemspec
@@ -18,8 +18,4 @@ Gem::Specification.new do |spec|
   spec.bindir = "exe"
   spec.executables = spec.files.grep(%r{\Aexe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
-  spec.add_dependency "async-http-faraday", ">= 0.0", "< 1.0"
-  spec.add_dependency "faraday", ">= 1.10", "< 3.0"
-  spec.add_dependency "faraday-net_http", ">= 1.0", "< 4.0"
-  spec.add_dependency "faraday-retry", ">= 1.0", "< 3.0"
 end
diff --git a/seed/ruby-sdk/server-sent-events/lib/fern_server_sent_events.rb b/seed/ruby-sdk/server-sent-events/lib/fern_server_sent_events.rb
index ae06a56b532..dab852152bb 100644
--- a/seed/ruby-sdk/server-sent-events/lib/fern_server_sent_events.rb
+++ b/seed/ruby-sdk/server-sent-events/lib/fern_server_sent_events.rb
@@ -1,43 +1,3 @@
 # frozen_string_literal: true
 
-require_relative "types_export"
-require_relative "requests"
-require_relative "fern_server_sent_events/completions/client"
-
-module SeedServerSentEventsClient
-  class Client
-    # @return [SeedServerSentEventsClient::CompletionsClient]
-    attr_reader :completions
-
-    # @param base_url [String]
-    # @param max_retries [Long] The number of times to retry a failed request, defaults to 2.
-    # @param timeout_in_seconds [Long]
-    # @return [SeedServerSentEventsClient::Client]
-    def initialize(base_url: nil, max_retries: nil, timeout_in_seconds: nil)
-      @request_client = SeedServerSentEventsClient::RequestClient.new(
-        base_url: base_url,
-        max_retries: max_retries,
-        timeout_in_seconds: timeout_in_seconds
-      )
-      @completions = SeedServerSentEventsClient::CompletionsClient.new(request_client: @request_client)
-    end
-  end
-
-  class AsyncClient
-    # @return [SeedServerSentEventsClient::AsyncCompletionsClient]
-    attr_reader :completions
-
-    # @param base_url [String]
-    # @param max_retries [Long] The number of times to retry a failed request, defaults to 2.
-    # @param timeout_in_seconds [Long]
-    # @return [SeedServerSentEventsClient::AsyncClient]
-    def initialize(base_url: nil, max_retries: nil, timeout_in_seconds: nil)
-      @async_request_client = SeedServerSentEventsClient::AsyncRequestClient.new(
-        base_url: base_url,
-        max_retries: max_retries,
-        timeout_in_seconds: timeout_in_seconds
-      )
-      @completions = SeedServerSentEventsClient::AsyncCompletionsClient.new(request_client: @async_request_client)
-    end
-  end
-end
+require_relative "fern_server_sent_events/completions/types/streamed_completion"
diff --git a/seed/ruby-sdk/server-sent-events/lib/fern_server_sent_events/completions/client.rb b/seed/ruby-sdk/server-sent-events/lib/fern_server_sent_events/completions/client.rb
deleted file mode 100644
index ec72526f0ea..00000000000
--- a/seed/ruby-sdk/server-sent-events/lib/fern_server_sent_events/completions/client.rb
+++ /dev/null
@@ -1,27 +0,0 @@
-# frozen_string_literal: true
-
-require_relative "../../requests"
-
-module SeedServerSentEventsClient
-  class CompletionsClient
-    # @return [SeedServerSentEventsClient::RequestClient]
-    attr_reader :request_client
-
-    # @param request_client [SeedServerSentEventsClient::RequestClient]
-    # @return [SeedServerSentEventsClient::CompletionsClient]
-    def initialize(request_client:)
-      @request_client = request_client
-    end
-  end
-
-  class AsyncCompletionsClient
-    # @return [SeedServerSentEventsClient::AsyncRequestClient]
-    attr_reader :request_client
-
-    # @param request_client [SeedServerSentEventsClient::AsyncRequestClient]
-    # @return [SeedServerSentEventsClient::AsyncCompletionsClient]
-    def initialize(request_client:)
-      @request_client = request_client
-    end
-  end
-end
diff --git a/seed/ruby-sdk/server-sent-events/lib/requests.rb b/seed/ruby-sdk/server-sent-events/lib/requests.rb
deleted file mode 100644
index c14ddbbfb1d..00000000000
--- a/seed/ruby-sdk/server-sent-events/lib/requests.rb
+++ /dev/null
@@ -1,140 +0,0 @@
-# frozen_string_literal: true
-
-require "faraday"
-require "faraday/retry"
-require "async/http/faraday"
-
-module SeedServerSentEventsClient
-  class RequestClient
-    # @return [Faraday]
-    attr_reader :conn
-    # @return [String]
-    attr_reader :base_url
-
-    # @param base_url [String]
-    # @param max_retries [Long] The number of times to retry a failed request, defaults to 2.
-    # @param timeout_in_seconds [Long]
-    # @return [SeedServerSentEventsClient::RequestClient]
-    def initialize(base_url: nil, max_retries: nil, timeout_in_seconds: nil)
-      @base_url = base_url
-      @conn = Faraday.new do |faraday|
-        faraday.request :json
-        faraday.response :raise_error, include_request: true
-        faraday.request :retry, { max: max_retries } unless max_retries.nil?
-        faraday.options.timeout = timeout_in_seconds unless timeout_in_seconds.nil?
-      end
-    end
-
-    # @param request_options [SeedServerSentEventsClient::RequestOptions]
-    # @return [String]
-    def get_url(request_options: nil)
-      request_options&.base_url || @base_url
-    end
-
-    # @return [Hash{String => String}]
-    def get_headers
-      {
-        "X-Fern-Language": "Ruby",
-        "X-Fern-SDK-Name": "fern_server_sent_events",
-        "X-Fern-SDK-Version": "0.0.1"
-      }
-    end
-  end
-
-  class AsyncRequestClient
-    # @return [Faraday]
-    attr_reader :conn
-    # @return [String]
-    attr_reader :base_url
-
-    # @param base_url [String]
-    # @param max_retries [Long] The number of times to retry a failed request, defaults to 2.
-    # @param timeout_in_seconds [Long]
-    # @return [SeedServerSentEventsClient::AsyncRequestClient]
-    def initialize(base_url: nil, max_retries: nil, timeout_in_seconds: nil)
-      @base_url = base_url
-      @conn = Faraday.new do |faraday|
-        faraday.request :json
-        faraday.response :raise_error, include_request: true
-        faraday.adapter :async_http
-        faraday.request :retry, { max: max_retries } unless max_retries.nil?
-        faraday.options.timeout = timeout_in_seconds unless timeout_in_seconds.nil?
-      end
-    end
-
-    # @param request_options [SeedServerSentEventsClient::RequestOptions]
-    # @return [String]
-    def get_url(request_options: nil)
-      request_options&.base_url || @base_url
-    end
-
-    # @return [Hash{String => String}]
-    def get_headers
-      {
-        "X-Fern-Language": "Ruby",
-        "X-Fern-SDK-Name": "fern_server_sent_events",
-        "X-Fern-SDK-Version": "0.0.1"
-      }
-    end
-  end
-
-  # Additional options for request-specific configuration when calling APIs via the
-  #  SDK.
-  class RequestOptions
-    # @return [String]
-    attr_reader :base_url
-    # @return [Hash{String => Object}]
-    attr_reader :additional_headers
-    # @return [Hash{String => Object}]
-    attr_reader :additional_query_parameters
-    # @return [Hash{String => Object}]
-    attr_reader :additional_body_parameters
-    # @return [Long]
-    attr_reader :timeout_in_seconds
-
-    # @param base_url [String]
-    # @param additional_headers [Hash{String => Object}]
-    # @param additional_query_parameters [Hash{String => Object}]
-    # @param additional_body_parameters [Hash{String => Object}]
-    # @param timeout_in_seconds [Long]
-    # @return [SeedServerSentEventsClient::RequestOptions]
-    def initialize(base_url: nil, additional_headers: nil, additional_query_parameters: nil,
-                   additional_body_parameters: nil, timeout_in_seconds: nil)
-      @base_url = base_url
-      @additional_headers = additional_headers
-      @additional_query_parameters = additional_query_parameters
-      @additional_body_parameters = additional_body_parameters
-      @timeout_in_seconds = timeout_in_seconds
-    end
-  end
-
-  # Additional options for request-specific configuration when calling APIs via the
-  #  SDK.
-  class IdempotencyRequestOptions
-    # @return [String]
-    attr_reader :base_url
-    # @return [Hash{String => Object}]
-    attr_reader :additional_headers
-    # @return [Hash{String => Object}]
-    attr_reader :additional_query_parameters
-    # @return [Hash{String => Object}]
-    attr_reader :additional_body_parameters
-    # @return [Long]
-    attr_reader :timeout_in_seconds
-
-    # @param base_url [String]
-    # @param additional_headers [Hash{String => Object}]
-    # @param additional_query_parameters [Hash{String => Object}]
-    # @param additional_body_parameters [Hash{String => Object}]
-    # @param timeout_in_seconds [Long]
-    # @return [SeedServerSentEventsClient::IdempotencyRequestOptions]
-    def initialize(base_url: nil, additional_headers: nil, additional_query_parameters: nil,
-                   additional_body_parameters: nil, timeout_in_seconds: nil)
-      @base_url = base_url
-      @additional_headers = additional_headers
-      @additional_query_parameters = additional_query_parameters
-      @additional_body_parameters = additional_body_parameters
-      @timeout_in_seconds = timeout_in_seconds
-    end
-  end
-end
diff --git a/seed/ruby-sdk/server-sent-events/lib/types_export.rb b/seed/ruby-sdk/server-sent-events/lib/types_export.rb
deleted file mode 100644
index dab852152bb..00000000000
--- a/seed/ruby-sdk/server-sent-events/lib/types_export.rb
+++ /dev/null
@@ -1,3 +0,0 @@
-# frozen_string_literal: true
-
-require_relative "fern_server_sent_events/completions/types/streamed_completion"
diff --git a/seed/ruby-sdk/server-sent-events/snippet.json b/seed/ruby-sdk/server-sent-events/snippet.json
index 0614251dd46..e69de29bb2d 100644
--- a/seed/ruby-sdk/server-sent-events/snippet.json
+++ b/seed/ruby-sdk/server-sent-events/snippet.json
@@ -1,4 +0,0 @@
-{
-    "endpoints": [],
-    "types": {}
-}
\ No newline at end of file
diff --git a/seed/ts-sdk/server-sent-events/README.md b/seed/ts-sdk/server-sent-events/README.md
index e1128c89a07..acb70e95f5b 100644
--- a/seed/ts-sdk/server-sent-events/README.md
+++ b/seed/ts-sdk/server-sent-events/README.md
@@ -1,6 +1,6 @@
 # Seed TypeScript Library
 
-[![fern shield](https://img.shields.io/badge/%F0%9F%8C%BF-SDK%20generated%20by%20Fern-brightgreen)](https://github.com/fern-api/fern)
+[![fern shield](https://img.shields.io/badge/%F0%9F%8C%BF-Built%20with%20Fern-brightgreen)](https://buildwithfern.com?utm_source=github&utm_medium=github&utm_campaign=readme&utm_source=Seed%2FTypeScript)
 [![npm shield](https://img.shields.io/npm/v/@fern/server-sent-events)](https://www.npmjs.com/package/@fern/server-sent-events)
 
 The Seed TypeScript library provides convenient access to the Seed API from TypeScript.
@@ -11,6 +11,10 @@ The Seed TypeScript library provides convenient access to the Seed API from Type
 npm i -s @fern/server-sent-events
 ```
 
+## Reference
+
+A full reference for this library is available [here](./reference.md).
+
 ## Usage
 
 Instantiate and use the client with the following:
diff --git a/seed/ts-sdk/server-sent-events/jest.config.js b/seed/ts-sdk/server-sent-events/jest.config.js
new file mode 100644
index 00000000000..35d6e65bf93
--- /dev/null
+++ b/seed/ts-sdk/server-sent-events/jest.config.js
@@ -0,0 +1,5 @@
+/** @type {import('jest').Config} */
+module.exports = {
+    preset: "ts-jest",
+    testEnvironment: "node",
+};
diff --git a/seed/ts-sdk/server-sent-events/package.json b/seed/ts-sdk/server-sent-events/package.json
index 3dc98b60480..1a0ddcd6a8f 100644
--- a/seed/ts-sdk/server-sent-events/package.json
+++ b/seed/ts-sdk/server-sent-events/package.json
@@ -16,13 +16,17 @@
         "form-data": "^4.0.0",
         "formdata-node": "^6.0.3",
         "node-fetch": "2.7.0",
-        "qs": "6.11.2"
+        "qs": "6.11.2",
+        "readable-stream": "^4.5.2"
     },
     "devDependencies": {
         "@types/url-join": "4.0.1",
         "@types/qs": "6.9.8",
         "@types/node-fetch": "2.6.9",
+        "@types/readable-stream": "^4.0.15",
         "fetch-mock-jest": "^1.5.1",
+        "webpack": "^5.94.0",
+        "ts-loader": "^9.3.1",
         "jest": "29.7.0",
         "@types/jest": "29.5.5",
         "ts-jest": "29.1.1",
diff --git a/seed/ts-sdk/server-sent-events/resolved-snippet-templates.md b/seed/ts-sdk/server-sent-events/resolved-snippet-templates.md
new file mode 100644
index 00000000000..4422ea50f16
--- /dev/null
+++ b/seed/ts-sdk/server-sent-events/resolved-snippet-templates.md
@@ -0,0 +1,11 @@
+```typescript
+import { SeedServerSentEventsClient } from "@fern/server-sent-events";
+
+const client = new SeedServerSentEventsClient({ environment: "YOUR_BASE_URL" });
+await client.completions.stream({
+  query: "string",
+});
+ 
+```                        
+
+
diff --git a/seed/ts-sdk/server-sent-events/src/core/fetcher/stream-wrappers/Node18UniversalStreamWrapper.ts b/seed/ts-sdk/server-sent-events/src/core/fetcher/stream-wrappers/Node18UniversalStreamWrapper.ts
index b8504841c77..4d7b7d52e8f 100644
--- a/seed/ts-sdk/server-sent-events/src/core/fetcher/stream-wrappers/Node18UniversalStreamWrapper.ts
+++ b/seed/ts-sdk/server-sent-events/src/core/fetcher/stream-wrappers/Node18UniversalStreamWrapper.ts
@@ -1,4 +1,4 @@
-import type { Writable } from "stream";
+import type { Writable } from "readable-stream";
 import { EventCallback, StreamWrapper } from "./chooseStreamWrapper";
 
 export class Node18UniversalStreamWrapper<ReadFormat extends Uint8Array | Uint16Array | Uint32Array>
diff --git a/seed/ts-sdk/server-sent-events/src/core/fetcher/stream-wrappers/NodePre18StreamWrapper.ts b/seed/ts-sdk/server-sent-events/src/core/fetcher/stream-wrappers/NodePre18StreamWrapper.ts
index f9bead21841..ba5f7276750 100644
--- a/seed/ts-sdk/server-sent-events/src/core/fetcher/stream-wrappers/NodePre18StreamWrapper.ts
+++ b/seed/ts-sdk/server-sent-events/src/core/fetcher/stream-wrappers/NodePre18StreamWrapper.ts
@@ -1,4 +1,4 @@
-import type { Readable, Writable } from "stream";
+import type { Readable, Writable } from "readable-stream";
 import { EventCallback, StreamWrapper } from "./chooseStreamWrapper";
 
 export class NodePre18StreamWrapper implements StreamWrapper<Writable, Buffer> {
diff --git a/seed/ts-sdk/server-sent-events/src/core/fetcher/stream-wrappers/UndiciStreamWrapper.ts b/seed/ts-sdk/server-sent-events/src/core/fetcher/stream-wrappers/UndiciStreamWrapper.ts
index 6725061ec27..263af00911f 100644
--- a/seed/ts-sdk/server-sent-events/src/core/fetcher/stream-wrappers/UndiciStreamWrapper.ts
+++ b/seed/ts-sdk/server-sent-events/src/core/fetcher/stream-wrappers/UndiciStreamWrapper.ts
@@ -78,7 +78,7 @@ export class UndiciStreamWrapper<ReadFormat extends Uint8Array | Uint16Array | U
         return this.pipe(dest);
     }
 
-    public unpipe(dest: UndiciStreamWrapper<ReadFormat> | WritableStream<any>): void {
+    public unpipe(dest: UndiciStreamWrapper<ReadFormat> | WritableStream): void {
         this.off("data", (chunk) => {
             if (dest instanceof UndiciStreamWrapper) {
                 dest._write(chunk);
diff --git a/seed/ts-sdk/server-sent-events/src/core/fetcher/stream-wrappers/chooseStreamWrapper.ts b/seed/ts-sdk/server-sent-events/src/core/fetcher/stream-wrappers/chooseStreamWrapper.ts
index d60991da089..2abd6b2ba1c 100644
--- a/seed/ts-sdk/server-sent-events/src/core/fetcher/stream-wrappers/chooseStreamWrapper.ts
+++ b/seed/ts-sdk/server-sent-events/src/core/fetcher/stream-wrappers/chooseStreamWrapper.ts
@@ -1,4 +1,4 @@
-import type { Readable } from "stream";
+import type { Readable } from "readable-stream";
 import { RUNTIME } from "../../runtime";
 
 export type EventCallback = (data?: any) => void;
@@ -25,7 +25,7 @@ export async function chooseStreamWrapper(responseBody: any): Promise<Promise<St
         return new (await import("./Node18UniversalStreamWrapper")).Node18UniversalStreamWrapper(
             responseBody as ReadableStream
         );
-    } else if (RUNTIME.type !== "node" && typeof fetch == "function") {
+    } else if (RUNTIME.type !== "node" && typeof fetch === "function") {
         return new (await import("./UndiciStreamWrapper")).UndiciStreamWrapper(responseBody as ReadableStream);
     } else {
         return new (await import("./NodePre18StreamWrapper")).NodePre18StreamWrapper(responseBody as Readable);
diff --git a/seed/ts-sdk/server-sent-events/src/core/schemas/Schema.ts b/seed/ts-sdk/server-sent-events/src/core/schemas/Schema.ts
index 19acc5dc44b..2a72eacec99 100644
--- a/seed/ts-sdk/server-sent-events/src/core/schemas/Schema.ts
+++ b/seed/ts-sdk/server-sent-events/src/core/schemas/Schema.ts
@@ -12,6 +12,7 @@ export interface BaseSchema<Raw, Parsed> {
 }
 
 export const SchemaType = {
+    BIGINT: "bigint",
     DATE: "date",
     ENUM: "enum",
     LIST: "list",
diff --git a/seed/ts-sdk/server-sent-events/src/core/schemas/builders/bigint/bigint.ts b/seed/ts-sdk/server-sent-events/src/core/schemas/builders/bigint/bigint.ts
new file mode 100644
index 00000000000..dc9c742e007
--- /dev/null
+++ b/seed/ts-sdk/server-sent-events/src/core/schemas/builders/bigint/bigint.ts
@@ -0,0 +1,50 @@
+import { BaseSchema, Schema, SchemaType } from "../../Schema";
+import { getErrorMessageForIncorrectType } from "../../utils/getErrorMessageForIncorrectType";
+import { maybeSkipValidation } from "../../utils/maybeSkipValidation";
+import { getSchemaUtils } from "../schema-utils";
+
+export function bigint(): Schema<string, bigint> {
+    const baseSchema: BaseSchema<string, bigint> = {
+        parse: (raw, { breadcrumbsPrefix = [] } = {}) => {
+            if (typeof raw !== "string") {
+                return {
+                    ok: false,
+                    errors: [
+                        {
+                            path: breadcrumbsPrefix,
+                            message: getErrorMessageForIncorrectType(raw, "string"),
+                        },
+                    ],
+                };
+            }
+            return {
+                ok: true,
+                value: BigInt(raw),
+            };
+        },
+        json: (bigint, { breadcrumbsPrefix = [] } = {}) => {
+            if (typeof bigint === "bigint") {
+                return {
+                    ok: true,
+                    value: bigint.toString(),
+                };
+            } else {
+                return {
+                    ok: false,
+                    errors: [
+                        {
+                            path: breadcrumbsPrefix,
+                            message: getErrorMessageForIncorrectType(bigint, "bigint"),
+                        },
+                    ],
+                };
+            }
+        },
+        getType: () => SchemaType.BIGINT,
+    };
+
+    return {
+        ...maybeSkipValidation(baseSchema),
+        ...getSchemaUtils(baseSchema),
+    };
+}
diff --git a/seed/ts-sdk/server-sent-events/src/core/schemas/builders/bigint/index.ts b/seed/ts-sdk/server-sent-events/src/core/schemas/builders/bigint/index.ts
new file mode 100644
index 00000000000..e5843043fcb
--- /dev/null
+++ b/seed/ts-sdk/server-sent-events/src/core/schemas/builders/bigint/index.ts
@@ -0,0 +1 @@
+export { bigint } from "./bigint";
diff --git a/seed/ts-sdk/server-sent-events/src/core/schemas/builders/index.ts b/seed/ts-sdk/server-sent-events/src/core/schemas/builders/index.ts
index 050cd2c4efb..65211f92522 100644
--- a/seed/ts-sdk/server-sent-events/src/core/schemas/builders/index.ts
+++ b/seed/ts-sdk/server-sent-events/src/core/schemas/builders/index.ts
@@ -1,3 +1,4 @@
+export * from "./bigint";
 export * from "./date";
 export * from "./enum";
 export * from "./lazy";
diff --git a/seed/ts-sdk/server-sent-events/src/core/schemas/utils/getErrorMessageForIncorrectType.ts b/seed/ts-sdk/server-sent-events/src/core/schemas/utils/getErrorMessageForIncorrectType.ts
index 438012df418..1a5c31027ce 100644
--- a/seed/ts-sdk/server-sent-events/src/core/schemas/utils/getErrorMessageForIncorrectType.ts
+++ b/seed/ts-sdk/server-sent-events/src/core/schemas/utils/getErrorMessageForIncorrectType.ts
@@ -9,9 +9,13 @@ function getTypeAsString(value: unknown): string {
     if (value === null) {
         return "null";
     }
+    if (value instanceof BigInt) {
+        return "BigInt";
+    }
     switch (typeof value) {
         case "string":
             return `"${value}"`;
+        case "bigint":
         case "number":
         case "boolean":
         case "undefined":
diff --git a/seed/ts-sdk/server-sent-events/src/version.ts b/seed/ts-sdk/server-sent-events/src/version.ts
new file mode 100644
index 00000000000..b643a3e3ea2
--- /dev/null
+++ b/seed/ts-sdk/server-sent-events/src/version.ts
@@ -0,0 +1 @@
+export const SDK_VERSION = "0.0.1";
diff --git a/seed/ts-sdk/server-sent-events/tests/unit/fetcher/stream-wrappers/Node18UniversalStreamWrapper.test.ts b/seed/ts-sdk/server-sent-events/tests/unit/fetcher/stream-wrappers/Node18UniversalStreamWrapper.test.ts
index e307b1589a7..1dc9be0cc0e 100644
--- a/seed/ts-sdk/server-sent-events/tests/unit/fetcher/stream-wrappers/Node18UniversalStreamWrapper.test.ts
+++ b/seed/ts-sdk/server-sent-events/tests/unit/fetcher/stream-wrappers/Node18UniversalStreamWrapper.test.ts
@@ -60,7 +60,7 @@ describe("Node18UniversalStreamWrapper", () => {
             },
         });
         const stream = new Node18UniversalStreamWrapper(rawStream);
-        const dest = new (await import("stream")).Writable({
+        const dest = new (await import("readable-stream")).Writable({
             write(chunk, encoding, callback) {
                 expect(chunk.toString()).toEqual("test");
                 callback();
diff --git a/seed/ts-sdk/server-sent-events/tests/unit/fetcher/stream-wrappers/NodePre18StreamWrapper.test.ts b/seed/ts-sdk/server-sent-events/tests/unit/fetcher/stream-wrappers/NodePre18StreamWrapper.test.ts
index 861142a08b0..0c99d3b2655 100644
--- a/seed/ts-sdk/server-sent-events/tests/unit/fetcher/stream-wrappers/NodePre18StreamWrapper.test.ts
+++ b/seed/ts-sdk/server-sent-events/tests/unit/fetcher/stream-wrappers/NodePre18StreamWrapper.test.ts
@@ -2,7 +2,7 @@ import { NodePre18StreamWrapper } from "../../../../src/core/fetcher/stream-wrap
 
 describe("NodePre18StreamWrapper", () => {
     it("should set encoding to utf-8", async () => {
-        const rawStream = (await import("stream")).Readable.from(["test", "test"]);
+        const rawStream = (await import("readable-stream")).Readable.from(["test", "test"]);
         const stream = new NodePre18StreamWrapper(rawStream);
         const setEncodingSpy = jest.spyOn(stream, "setEncoding");
 
@@ -12,7 +12,7 @@ describe("NodePre18StreamWrapper", () => {
     });
 
     it("should register an event listener for readable", async () => {
-        const rawStream = (await import("stream")).Readable.from(["test", "test"]);
+        const rawStream = (await import("readable-stream")).Readable.from(["test", "test"]);
         const stream = new NodePre18StreamWrapper(rawStream);
         const onSpy = jest.spyOn(stream, "on");
 
@@ -22,7 +22,7 @@ describe("NodePre18StreamWrapper", () => {
     });
 
     it("should remove an event listener for data", async () => {
-        const rawStream = (await import("stream")).Readable.from(["test", "test"]);
+        const rawStream = (await import("readable-stream")).Readable.from(["test", "test"]);
         const stream = new NodePre18StreamWrapper(rawStream);
         const offSpy = jest.spyOn(stream, "off");
 
@@ -34,9 +34,9 @@ describe("NodePre18StreamWrapper", () => {
     });
 
     it("should write to dest when calling pipe to node writable stream", async () => {
-        const rawStream = (await import("stream")).Readable.from(["test", "test"]);
+        const rawStream = (await import("readable-stream")).Readable.from(["test", "test"]);
         const stream = new NodePre18StreamWrapper(rawStream);
-        const dest = new (await import("stream")).Writable({
+        const dest = new (await import("readable-stream")).Writable({
             write(chunk, encoding, callback) {
                 expect(chunk.toString()).toEqual("test");
                 callback();
@@ -47,10 +47,10 @@ describe("NodePre18StreamWrapper", () => {
     });
 
     it("should write nothing when calling pipe and unpipe", async () => {
-        const rawStream = (await import("stream")).Readable.from(["test", "test"]);
+        const rawStream = (await import("readable-stream")).Readable.from(["test", "test"]);
         const stream = new NodePre18StreamWrapper(rawStream);
         const buffer: Uint8Array[] = [];
-        const dest = new (await import("stream")).Writable({
+        const dest = new (await import("readable-stream")).Writable({
             write(chunk, encoding, callback) {
                 buffer.push(chunk);
                 callback();
@@ -63,7 +63,7 @@ describe("NodePre18StreamWrapper", () => {
     });
 
     it("should destroy the stream", async () => {
-        const rawStream = (await import("stream")).Readable.from(["test", "test"]);
+        const rawStream = (await import("readable-stream")).Readable.from(["test", "test"]);
         const stream = new NodePre18StreamWrapper(rawStream);
         const destroySpy = jest.spyOn(stream, "destroy");
 
@@ -73,7 +73,7 @@ describe("NodePre18StreamWrapper", () => {
     });
 
     it("should pause the stream and resume", async () => {
-        const rawStream = (await import("stream")).Readable.from(["test", "test"]);
+        const rawStream = (await import("readable-stream")).Readable.from(["test", "test"]);
         const stream = new NodePre18StreamWrapper(rawStream);
         const pauseSpy = jest.spyOn(stream, "pause");
 
@@ -86,7 +86,7 @@ describe("NodePre18StreamWrapper", () => {
     });
 
     it("should read the stream", async () => {
-        const rawStream = (await import("stream")).Readable.from(["test", "test"]);
+        const rawStream = (await import("readable-stream")).Readable.from(["test", "test"]);
         const stream = new NodePre18StreamWrapper(rawStream);
 
         expect(await stream.read()).toEqual("test");
@@ -94,7 +94,7 @@ describe("NodePre18StreamWrapper", () => {
     });
 
     it("should read the stream as text", async () => {
-        const rawStream = (await import("stream")).Readable.from(["test", "test"]);
+        const rawStream = (await import("readable-stream")).Readable.from(["test", "test"]);
         const stream = new NodePre18StreamWrapper(rawStream);
 
         const data = await stream.text();
@@ -103,7 +103,7 @@ describe("NodePre18StreamWrapper", () => {
     });
 
     it("should read the stream as json", async () => {
-        const rawStream = (await import("stream")).Readable.from([JSON.stringify({ test: "test" })]);
+        const rawStream = (await import("readable-stream")).Readable.from([JSON.stringify({ test: "test" })]);
         const stream = new NodePre18StreamWrapper(rawStream);
 
         const data = await stream.json();
@@ -112,7 +112,7 @@ describe("NodePre18StreamWrapper", () => {
     });
 
     it("should allow use with async iteratable stream", async () => {
-        const rawStream = (await import("stream")).Readable.from(["test", "test"]);
+        const rawStream = (await import("readable-stream")).Readable.from(["test", "test"]);
         let data = "";
         const stream = new NodePre18StreamWrapper(rawStream);
         for await (const chunk of stream) {
diff --git a/seed/ts-sdk/server-sent-events/tests/unit/fetcher/stream-wrappers/chooseStreamWrapper.test.ts b/seed/ts-sdk/server-sent-events/tests/unit/fetcher/stream-wrappers/chooseStreamWrapper.test.ts
index aff7579e47a..17cf37a2f7f 100644
--- a/seed/ts-sdk/server-sent-events/tests/unit/fetcher/stream-wrappers/chooseStreamWrapper.test.ts
+++ b/seed/ts-sdk/server-sent-events/tests/unit/fetcher/stream-wrappers/chooseStreamWrapper.test.ts
@@ -21,7 +21,7 @@ describe("chooseStreamWrapper", () => {
     });
 
     it('should return a NodePre18StreamWrapper when RUNTIME.type is "node" and RUNTIME.parsedVersion is not null and RUNTIME.parsedVersion is less than 18', async () => {
-        const stream = await import("stream");
+        const stream = await import("readable-stream");
         const expected = new NodePre18StreamWrapper(new stream.Readable());
 
         RUNTIME.type = "node";
diff --git a/seed/ts-sdk/server-sent-events/tests/unit/fetcher/stream-wrappers/webpack.test.ts b/seed/ts-sdk/server-sent-events/tests/unit/fetcher/stream-wrappers/webpack.test.ts
new file mode 100644
index 00000000000..557db6dc4ef
--- /dev/null
+++ b/seed/ts-sdk/server-sent-events/tests/unit/fetcher/stream-wrappers/webpack.test.ts
@@ -0,0 +1,38 @@
+import webpack from "webpack";
+
+describe("test env compatibility", () => {
+    test("webpack", () => {
+        return new Promise<void>((resolve, reject) => {
+            webpack(
+                {
+                    mode: "production",
+                    entry: "./src/index.ts",
+                    module: {
+                        rules: [
+                            {
+                                test: /\.tsx?$/,
+                                use: "ts-loader",
+                                exclude: /node_modules/,
+                            },
+                        ],
+                    },
+                    resolve: {
+                        extensions: [".tsx", ".ts", ".js"],
+                    },
+                },
+                (err, stats) => {
+                    try {
+                        expect(err).toBe(null);
+                        if (stats?.hasErrors()) {
+                            console.log(stats?.toString());
+                        }
+                        expect(stats?.hasErrors()).toBe(false);
+                        resolve();
+                    } catch (error) {
+                        reject(error);
+                    }
+                }
+            );
+        });
+    }, 60_000);
+});
diff --git a/seed/ts-sdk/server-sent-events/tests/unit/zurg/bigint/bigint.test.ts b/seed/ts-sdk/server-sent-events/tests/unit/zurg/bigint/bigint.test.ts
new file mode 100644
index 00000000000..cf9935a749a
--- /dev/null
+++ b/seed/ts-sdk/server-sent-events/tests/unit/zurg/bigint/bigint.test.ts
@@ -0,0 +1,24 @@
+import { bigint } from "../../../../src/core/schemas/builders/bigint";
+import { itSchema } from "../utils/itSchema";
+import { itValidateJson, itValidateParse } from "../utils/itValidate";
+
+describe("bigint", () => {
+    itSchema("converts between raw string and parsed bigint", bigint(), {
+        raw: "123456789012345678901234567890123456789012345678901234567890",
+        parsed: BigInt("123456789012345678901234567890123456789012345678901234567890"),
+    });
+
+    itValidateParse("non-string", bigint(), 42, [
+        {
+            message: "Expected string. Received 42.",
+            path: [],
+        },
+    ]);
+
+    itValidateJson("non-bigint", bigint(), "hello", [
+        {
+            message: 'Expected bigint. Received "hello".',
+            path: [],
+        },
+    ]);
+});