diff --git a/CHANGELOG.md b/CHANGELOG.md
index ed7e9ad5705..611ebca352c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,11 @@
       config files in the project/workspace root. This pattern is preferred when possible.
 - Updated task option `runInCI` to support the values "always" (always run) and "affected" (only run
   if affected, same as `true`).
+- Updated the `extends` setting in `.moon/workspace.yml`, `toolchain.yml`, and `tasks.yml`, to support a list of files/URLs to extend.
+
+#### 🐞 Fixes
+
+- Fixed a panic that could occur during command argument parsing.
 
 ## 1.30.6
 
diff --git a/crates/args/src/lib.rs b/crates/args/src/lib.rs
index 5bca163df51..ba45f060784 100644
--- a/crates/args/src/lib.rs
+++ b/crates/args/src/lib.rs
@@ -95,7 +95,7 @@ where
         // Better way to do this?
         let has_special_chars =
             // Multi chars
-            bytes
+            bytes_len > 0 && bytes
                 .windows(bytes_len)
                 .any(|window| multi_chars.iter().any(|c| *c == window))
             ||
diff --git a/crates/codegen/src/codegen.rs b/crates/codegen/src/codegen.rs
index b8baf7b0ea4..4335296a2bd 100644
--- a/crates/codegen/src/codegen.rs
+++ b/crates/codegen/src/codegen.rs
@@ -143,7 +143,7 @@ impl<'app> CodeGenerator<'app> {
 
             let mut extends = vec![];
 
-            for extend_id in &template.config.extends {
+            for extend_id in template.config.extends.to_list() {
                 extends.push(self.get_template(extend_id)?);
             }
 
diff --git a/crates/codegen/src/templates_command.rs b/crates/codegen/src/templates_command.rs
index 1a1f93587ce..303595146d8 100644
--- a/crates/codegen/src/templates_command.rs
+++ b/crates/codegen/src/templates_command.rs
@@ -32,6 +32,7 @@ pub async fn templates_command(
                 template
                     .config
                     .extends
+                    .to_list()
                     .iter()
                     .map(color::id)
                     .collect::<Vec<_>>()
diff --git a/crates/config-schema/src/typescript_types.rs b/crates/config-schema/src/typescript_types.rs
index a32d19f5aca..9f49f0c9c4c 100644
--- a/crates/config-schema/src/typescript_types.rs
+++ b/crates/config-schema/src/typescript_types.rs
@@ -63,7 +63,11 @@ fn generate_tasks(out_dir: &Path) -> miette::Result<()> {
     generator.add::<PartialInheritedTasksConfig>();
     generator.generate(
         out_dir.join("tasks-config.ts"),
-        TypeScriptRenderer::default(),
+        TypeScriptRenderer::new(TypeScriptOptions {
+            exclude_references: vec!["ExtendsFrom".into()],
+            external_types: HashMap::from_iter([("./common".into(), vec!["ExtendsFrom".into()])]),
+            ..Default::default()
+        }),
     )
 }
 
@@ -85,7 +89,11 @@ fn generate_toolchain(out_dir: &Path) -> miette::Result<()> {
     generator.add::<PartialToolchainConfig>();
     generator.generate(
         out_dir.join("toolchain-config.ts"),
-        TypeScriptRenderer::default(),
+        TypeScriptRenderer::new(TypeScriptOptions {
+            exclude_references: vec!["ExtendsFrom".into()],
+            external_types: HashMap::from_iter([("./common".into(), vec!["ExtendsFrom".into()])]),
+            ..Default::default()
+        }),
     )
 }
 
@@ -96,11 +104,11 @@ fn generate_workspace(out_dir: &Path) -> miette::Result<()> {
     generator.generate(
         out_dir.join("workspace-config.ts"),
         TypeScriptRenderer::new(TypeScriptOptions {
-            exclude_references: vec!["PluginLocator".into()],
-            external_types: HashMap::from_iter([(
-                "./toolchain-config".into(),
-                vec!["PluginLocator".into()],
-            )]),
+            exclude_references: vec!["ExtendsFrom".into(), "PluginLocator".into()],
+            external_types: HashMap::from_iter([
+                ("./common".into(), vec!["ExtendsFrom".into()]),
+                ("./toolchain-config".into(), vec!["PluginLocator".into()]),
+            ]),
             ..Default::default()
         }),
     )
diff --git a/crates/config/src/inherited_tasks_config.rs b/crates/config/src/inherited_tasks_config.rs
index 33ee7940d14..49a419fdea3 100644
--- a/crates/config/src/inherited_tasks_config.rs
+++ b/crates/config/src/inherited_tasks_config.rs
@@ -42,10 +42,10 @@ cacheable!(
         )]
         pub schema: String,
 
-        /// Extends another tasks configuration file. Supports a relative
+        /// Extends one or many task configuration files. Supports a relative
         /// file path or a secure URL.
-        #[setting(extend, validate = validate::extends_string)]
-        pub extends: Option<String>,
+        #[setting(extend, validate = validate::extends_from)]
+        pub extends: Option<schematic::ExtendsFrom>,
 
         /// A mapping of group IDs to a list of file paths, globs, and
         /// environment variables, that can be referenced from tasks.
diff --git a/crates/config/src/shapes/poly.rs b/crates/config/src/shapes/poly.rs
index 6e0f01f89c1..b7aa45b3a0d 100644
--- a/crates/config/src/shapes/poly.rs
+++ b/crates/config/src/shapes/poly.rs
@@ -25,7 +25,14 @@ impl<T: Schematic + Clone> OneOrMany<T> {
         }
     }
 
-    pub fn to_list(&self) -> Vec<T> {
+    pub fn to_list(&self) -> Vec<&T> {
+        match self {
+            Self::One(item) => vec![item],
+            Self::Many(list) => list.iter().collect(),
+        }
+    }
+
+    pub fn to_owned_list(&self) -> Vec<T> {
         match self {
             Self::One(item) => vec![item.to_owned()],
             Self::Many(list) => list.to_owned(),
diff --git a/crates/config/src/template_config.rs b/crates/config/src/template_config.rs
index 9ee1bf1756f..ebe90539189 100644
--- a/crates/config/src/template_config.rs
+++ b/crates/config/src/template_config.rs
@@ -1,3 +1,4 @@
+use crate::shapes::OneOrMany;
 use moon_common::Id;
 use rustc_hash::FxHashMap;
 use schematic::{validate, Config, ValidateError};
@@ -235,7 +236,7 @@ pub struct TemplateConfig {
     pub destination: Option<String>,
 
     /// Extends one or many other templates.
-    pub extends: Vec<Id>,
+    pub extends: OneOrMany<Id>,
 
     /// Overrides the ID of the template, instead of using the folder name.
     pub id: Option<Id>,
diff --git a/crates/config/src/toolchain_config.rs b/crates/config/src/toolchain_config.rs
index 65f148b51b0..37f176d9945 100644
--- a/crates/config/src/toolchain_config.rs
+++ b/crates/config/src/toolchain_config.rs
@@ -36,10 +36,10 @@ pub struct ToolchainConfig {
     )]
     pub schema: String,
 
-    /// Extends another toolchain configuration file. Supports a relative
+    /// Extends one or many toolchain configuration files. Supports a relative
     /// file path or a secure URL.
-    #[setting(extend, validate = validate::extends_string)]
-    pub extends: Option<String>,
+    #[setting(extend, validate = validate::extends_from)]
+    pub extends: Option<schematic::ExtendsFrom>,
 
     /// Configures and enables the Bun platform.
     #[setting(nested)]
diff --git a/crates/config/src/workspace_config.rs b/crates/config/src/workspace_config.rs
index 8c4bbc33d81..5fa6c3657bb 100644
--- a/crates/config/src/workspace_config.rs
+++ b/crates/config/src/workspace_config.rs
@@ -118,10 +118,10 @@ pub struct WorkspaceConfig {
     #[setting(nested)]
     pub experiments: ExperimentsConfig,
 
-    /// Extends another workspace configuration file. Supports a relative
+    /// Extends one or many workspace configuration file. Supports a relative
     /// file path or a secure URL.
-    #[setting(extend, validate = validate::extends_string)]
-    pub extends: Option<String>,
+    #[setting(extend, validate = validate::extends_from)]
+    pub extends: Option<schematic::ExtendsFrom>,
 
     /// Configures extensions that can be executed with `moon ext`.
     #[setting(nested)]
diff --git a/crates/task-builder/src/tasks_builder.rs b/crates/task-builder/src/tasks_builder.rs
index c0b777b2bfc..05022c83aaa 100644
--- a/crates/task-builder/src/tasks_builder.rs
+++ b/crates/task-builder/src/tasks_builder.rs
@@ -399,7 +399,7 @@ impl<'proj> TasksBuilder<'proj> {
             if !config.toolchain.is_empty() {
                 task.toolchains = config
                     .toolchain
-                    .to_list()
+                    .to_owned_list()
                     .into_iter()
                     .filter(|tc| self.context.enabled_toolchains.contains(tc))
                     .collect();
@@ -635,7 +635,7 @@ impl<'proj> TasksBuilder<'proj> {
             }
 
             if let Some(os) = &config.os {
-                options.os = Some(os.to_list());
+                options.os = Some(os.to_owned_list());
             }
 
             if let Some(output_style) = &config.output_style {
diff --git a/crates/task-runner/src/command_executor.rs b/crates/task-runner/src/command_executor.rs
index 0454ac999ab..21dcc23d26a 100644
--- a/crates/task-runner/src/command_executor.rs
+++ b/crates/task-runner/src/command_executor.rs
@@ -246,7 +246,7 @@ impl<'task> CommandExecutor<'task> {
     }
 
     fn monitor_running_status(&mut self) {
-        if self.persistent || self.interactive {
+        if self.persistent {
             return;
         }
 
diff --git a/packages/types/src/common.ts b/packages/types/src/common.ts
index 196b6cd03e0..d5a174a1db3 100644
--- a/packages/types/src/common.ts
+++ b/packages/types/src/common.ts
@@ -12,3 +12,5 @@ export interface Runtime {
 	requirement?: string;
 	overridden?: boolean;
 }
+
+export type ExtendsFrom = string[] | string;
diff --git a/packages/types/src/project-config.ts b/packages/types/src/project-config.ts
index bb31fbd68e0..9a61902d329 100644
--- a/packages/types/src/project-config.ts
+++ b/packages/types/src/project-config.ts
@@ -2,8 +2,8 @@
 
 /* eslint-disable */
 
-import type { PartialTaskConfig, PlatformType, TaskConfig } from './tasks-config';
 import type { UnresolvedVersionSpec } from './toolchain-config';
+import type { PartialTaskConfig, PlatformType, TaskConfig } from './tasks-config';
 
 /** The task-to-task relationship of the dependency. */
 export type DependencyType = 'cleanup' | 'required' | 'optional';
diff --git a/packages/types/src/tasks-config.ts b/packages/types/src/tasks-config.ts
index 061bf4332f4..65a0fc211da 100644
--- a/packages/types/src/tasks-config.ts
+++ b/packages/types/src/tasks-config.ts
@@ -2,6 +2,8 @@
 
 /* eslint-disable */
 
+import type { ExtendsFrom } from './common';
+
 export type TaskArgs = null | string | string[];
 
 /** Expanded information about a task dependency. */
@@ -261,10 +263,10 @@ export interface InheritedTasksConfig {
 	/** @default 'https://moonrepo.dev/schemas/tasks.json' */
 	$schema?: string;
 	/**
-	 * Extends another tasks configuration file. Supports a relative
+	 * Extends one or many task configuration files. Supports a relative
 	 * file path or a secure URL.
 	 */
-	extends: string | null;
+	extends: ExtendsFrom | null;
 	/**
 	 * A mapping of group IDs to a list of file paths, globs, and
 	 * environment variables, that can be referenced from tasks.
@@ -509,10 +511,10 @@ export interface PartialInheritedTasksConfig {
 	/** @default 'https://moonrepo.dev/schemas/tasks.json' */
 	$schema?: string | null;
 	/**
-	 * Extends another tasks configuration file. Supports a relative
+	 * Extends one or many task configuration files. Supports a relative
 	 * file path or a secure URL.
 	 */
-	extends?: string | null;
+	extends?: ExtendsFrom | null;
 	/**
 	 * A mapping of group IDs to a list of file paths, globs, and
 	 * environment variables, that can be referenced from tasks.
diff --git a/packages/types/src/template-config.ts b/packages/types/src/template-config.ts
index db9ea77308c..a60ddc6b4f8 100644
--- a/packages/types/src/template-config.ts
+++ b/packages/types/src/template-config.ts
@@ -113,7 +113,7 @@ export interface TemplateConfig {
 	 */
 	destination: string | null;
 	/** Extends one or many other templates. */
-	extends: string[];
+	extends: string | string[];
 	/** Overrides the ID of the template, instead of using the folder name. */
 	id: string | null;
 	/** A human-readable title for the template. */
@@ -218,7 +218,7 @@ export interface PartialTemplateConfig {
 	 */
 	destination?: string | null;
 	/** Extends one or many other templates. */
-	extends?: string[] | null;
+	extends?: string | string[] | null;
 	/** Overrides the ID of the template, instead of using the folder name. */
 	id?: string | null;
 	/** A human-readable title for the template. */
diff --git a/packages/types/src/toolchain-config.ts b/packages/types/src/toolchain-config.ts
index 1762e3021f1..3ec84cfb937 100644
--- a/packages/types/src/toolchain-config.ts
+++ b/packages/types/src/toolchain-config.ts
@@ -2,6 +2,8 @@
 
 /* eslint-disable */
 
+import type { ExtendsFrom } from './common';
+
 /** Formats that a `package.json` version dependency can be. */
 export type NodeVersionFormat =
 	| 'file'
@@ -400,10 +402,10 @@ export interface ToolchainConfig {
 	/** Configures and enables the Deno platform. */
 	deno: DenoConfig | null;
 	/**
-	 * Extends another toolchain configuration file. Supports a relative
+	 * Extends one or many toolchain configuration files. Supports a relative
 	 * file path or a secure URL.
 	 */
-	extends: string | null;
+	extends: ExtendsFrom | null;
 	/** Configures moon itself. */
 	moon: MoonConfig;
 	/** Configures and enables the Node.js platform. */
@@ -791,10 +793,10 @@ export interface PartialToolchainConfig {
 	/** Configures and enables the Deno platform. */
 	deno?: PartialDenoConfig | null;
 	/**
-	 * Extends another toolchain configuration file. Supports a relative
+	 * Extends one or many toolchain configuration files. Supports a relative
 	 * file path or a secure URL.
 	 */
-	extends?: string | null;
+	extends?: ExtendsFrom | null;
 	/** Configures moon itself. */
 	moon?: PartialMoonConfig | null;
 	/** Configures and enables the Node.js platform. */
diff --git a/packages/types/src/workspace-config.ts b/packages/types/src/workspace-config.ts
index dbfc915d2b7..2204fb1cbbe 100644
--- a/packages/types/src/workspace-config.ts
+++ b/packages/types/src/workspace-config.ts
@@ -2,6 +2,7 @@
 
 /* eslint-disable */
 
+import type { ExtendsFrom } from './common';
 import type { PluginLocator } from './toolchain-config';
 
 /** How to order ownership rules within the generated file. */
@@ -371,10 +372,10 @@ export interface WorkspaceConfig {
 	/** Configures experiments across the entire moon workspace. */
 	experiments: ExperimentsConfig;
 	/**
-	 * Extends another workspace configuration file. Supports a relative
+	 * Extends one or many workspace configuration file. Supports a relative
 	 * file path or a secure URL.
 	 */
-	extends: string | null;
+	extends: ExtendsFrom | null;
 	/** Configures extensions that can be executed with `moon ext`. */
 	extensions: Record<string, ExtensionConfig>;
 	/** Configures the generator for scaffolding from templates. */
@@ -748,10 +749,10 @@ export interface PartialWorkspaceConfig {
 	/** Configures experiments across the entire moon workspace. */
 	experiments?: PartialExperimentsConfig | null;
 	/**
-	 * Extends another workspace configuration file. Supports a relative
+	 * Extends one or many workspace configuration file. Supports a relative
 	 * file path or a secure URL.
 	 */
-	extends?: string | null;
+	extends?: ExtendsFrom | null;
 	/** Configures extensions that can be executed with `moon ext`. */
 	extensions?: Record<string, PartialExtensionConfig> | null;
 	/** Configures the generator for scaffolding from templates. */
diff --git a/website/docs/config/tasks.mdx b/website/docs/config/tasks.mdx
index 4a6c6ff8973..31d882cec77 100644
--- a/website/docs/config/tasks.mdx
+++ b/website/docs/config/tasks.mdx
@@ -20,9 +20,9 @@ $schema: 'https://moonrepo.dev/schemas/tasks.json'
 
 <HeadingApiLink to="/api/types/interface/InheritedTasksConfig#extends" />
 
-Defines an external `.moon/tasks.yml` to extend and inherit settings from. Perfect for reusability
-and sharing configuration across repositories and projects. When defined, this setting must be an
-HTTPS URL _or_ relative file system path that points to a valid YAML document!
+Defines one or many external `.moon/tasks.yml`'s to extend and inherit settings from. Perfect for
+reusability and sharing configuration across repositories and projects. When defined, this setting
+must be an HTTPS URL _or_ relative file system path that points to a valid YAML document!
 
 ```yaml title=".moon/tasks.yml" {1}
 extends: 'https://raw.githubusercontent.com/organization/repository/master/.moon/tasks.yml'
diff --git a/website/docs/config/template.mdx b/website/docs/config/template.mdx
index 261a7a2a4a5..b4b56f96656 100644
--- a/website/docs/config/template.mdx
+++ b/website/docs/config/template.mdx
@@ -71,7 +71,7 @@ destination: 'packages/[name]'
 
 <HeadingApiLink to="/api/types/interface/TemplateConfig#extends" />
 
-A list of other templates that this template should extend. Will deeply inherit all template files
+One or many other templates that this template should extend. Will deeply inherit all template files
 and variables.
 
 ```yaml title="template.yml"
diff --git a/website/docs/config/toolchain.mdx b/website/docs/config/toolchain.mdx
index ce75b21f964..866e8a7e326 100644
--- a/website/docs/config/toolchain.mdx
+++ b/website/docs/config/toolchain.mdx
@@ -23,9 +23,9 @@ $schema: 'https://moonrepo.dev/schemas/toolchain.json'
 
 <HeadingApiLink to="/api/types/interface/ToolchainConfig#extends" />
 
-Defines an external `.moon/toolchain.yml` to extend and inherit settings from. Perfect for
-reusability and sharing configuration across repositories and projects. When defined, this setting
-must be an HTTPS URL _or_ relative file system path that points to a valid YAML document!
+Defines one or many external `.moon/toolchain.yml`'s to extend and inherit settings from. Perfect
+for reusability and sharing configuration across repositories and projects. When defined, this
+setting must be an HTTPS URL _or_ relative file system path that points to a valid YAML document!
 
 ```yaml title=".moon/toolchain.yml" {1}
 extends: 'https://raw.githubusercontent.com/organization/repository/master/.moon/toolchain.yml'
diff --git a/website/docs/config/workspace.mdx b/website/docs/config/workspace.mdx
index 2a065a5a48a..3e85cc4a868 100644
--- a/website/docs/config/workspace.mdx
+++ b/website/docs/config/workspace.mdx
@@ -20,9 +20,9 @@ $schema: 'https://moonrepo.dev/schemas/workspace.json'
 
 <HeadingApiLink to="/api/types/interface/WorkspaceConfig#extends" />
 
-Defines an external `.moon/workspace.yml` to extend and inherit settings from. Perfect for
-reusability and sharing configuration across repositories and projects. When defined, this setting
-must be an HTTPS URL _or_ relative file system path that points to a valid YAML document!
+Defines one or many external `.moon/workspace.yml`'s to extend and inherit settings from. Perfect
+for reusability and sharing configuration across repositories and projects. When defined, this
+setting must be an HTTPS URL _or_ relative file system path that points to a valid YAML document!
 
 ```yaml title=".moon/workspace.yml" {1}
 extends: 'https://raw.githubusercontent.com/organization/repository/master/.moon/workspace.yml'
diff --git a/website/static/schemas/tasks.json b/website/static/schemas/tasks.json
index 8307cc5d898..fec3332001b 100644
--- a/website/static/schemas/tasks.json
+++ b/website/static/schemas/tasks.json
@@ -10,10 +10,10 @@
     },
     "extends": {
       "title": "extends",
-      "description": "Extends another tasks configuration file. Supports a relative file path or a secure URL.",
+      "description": "Extends one or many task configuration files. Supports a relative file path or a secure URL.",
       "anyOf": [
         {
-          "type": "string"
+          "$ref": "#/definitions/ExtendsFrom"
         },
         {
           "type": "null"
@@ -76,6 +76,19 @@
   },
   "additionalProperties": false,
   "definitions": {
+    "ExtendsFrom": {
+      "anyOf": [
+        {
+          "type": "string"
+        },
+        {
+          "type": "array",
+          "items": {
+            "type": "string"
+          }
+        }
+      ]
+    },
     "PlatformType": {
       "description": "Platforms that each programming language can belong to.",
       "type": "string",
diff --git a/website/static/schemas/template.json b/website/static/schemas/template.json
index daffbc1b2fa..057003305c7 100644
--- a/website/static/schemas/template.json
+++ b/website/static/schemas/template.json
@@ -29,10 +29,17 @@
     "extends": {
       "title": "extends",
       "description": "Extends one or many other templates.",
-      "type": "array",
-      "items": {
-        "type": "string"
-      }
+      "anyOf": [
+        {
+          "type": "string"
+        },
+        {
+          "type": "array",
+          "items": {
+            "type": "string"
+          }
+        }
+      ]
     },
     "id": {
       "title": "id",
diff --git a/website/static/schemas/toolchain.json b/website/static/schemas/toolchain.json
index b4cc88b5fa4..beba9ba5392 100644
--- a/website/static/schemas/toolchain.json
+++ b/website/static/schemas/toolchain.json
@@ -34,10 +34,10 @@
     },
     "extends": {
       "title": "extends",
-      "description": "Extends another toolchain configuration file. Supports a relative file path or a secure URL.",
+      "description": "Extends one or many toolchain configuration files. Supports a relative file path or a secure URL.",
       "anyOf": [
         {
-          "type": "string"
+          "$ref": "#/definitions/ExtendsFrom"
         },
         {
           "type": "null"
@@ -327,6 +327,19 @@
       },
       "additionalProperties": false
     },
+    "ExtendsFrom": {
+      "anyOf": [
+        {
+          "type": "string"
+        },
+        {
+          "type": "array",
+          "items": {
+            "type": "string"
+          }
+        }
+      ]
+    },
     "MoonConfig": {
       "description": "Configures how and where updates will be received.",
       "type": "object",
diff --git a/website/static/schemas/workspace.json b/website/static/schemas/workspace.json
index 659db03360e..d40531744c0 100644
--- a/website/static/schemas/workspace.json
+++ b/website/static/schemas/workspace.json
@@ -47,10 +47,10 @@
     },
     "extends": {
       "title": "extends",
-      "description": "Extends another workspace configuration file. Supports a relative file path or a secure URL.",
+      "description": "Extends one or many workspace configuration file. Supports a relative file path or a secure URL.",
       "anyOf": [
         {
-          "type": "string"
+          "$ref": "#/definitions/ExtendsFrom"
         },
         {
           "type": "null"
@@ -352,6 +352,19 @@
       },
       "additionalProperties": false
     },
+    "ExtendsFrom": {
+      "anyOf": [
+        {
+          "type": "string"
+        },
+        {
+          "type": "array",
+          "items": {
+            "type": "string"
+          }
+        }
+      ]
+    },
     "ExtensionConfig": {
       "description": "Configures an individual extension.",
       "type": "object",