diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index df4591b..71b0d53 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,9 +1,12 @@
 name: CI
 on:
   push:
-    branches: [ main ]
+    branches:
+      - main
   pull_request:
-    branches: [ main ]
+    types:
+      - opened
+      - synchronize
 jobs:
   ci:
     runs-on: ubuntu-latest
@@ -13,15 +16,19 @@ jobs:
           - 3.0
           - 3.1
           - 3.2
+          - 3.3
           - jruby
-          # - jruby-head
           - truffleruby
-          # - truffleruby-head
+      fail-fast: false
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+      - run: npm install -g tsx
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}
           bundler-cache: true
       - run: bundle exec standardrb
-      - run: COVERAGE=false bundle exec rake test
+      - run: COVERAGE=0 TEST_NODE_PARITY=1 bundle exec rake test
diff --git a/.gitignore b/.gitignore
index ce5d33d..7397957 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,6 +13,5 @@ transloadit-*.gem
 
 .DS_Store
 env.sh
-
-# Bundle directory
+.env
 vendor/bundle/
diff --git a/.vscode/ruby-sdk.code-workspace b/.vscode/ruby-sdk.code-workspace
new file mode 100644
index 0000000..ee9fe3c
--- /dev/null
+++ b/.vscode/ruby-sdk.code-workspace
@@ -0,0 +1,13 @@
+{
+	"folders": [
+		{
+			"path": ".."
+		}
+	],
+	"settings": {
+		"workbench.colorCustomizations": {
+			"titleBar.activeForeground": "#ffffff",
+			"titleBar.activeBackground": "#cc0000"
+		},
+	}
+}
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..03f7d67
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,18 @@
+.PHONY: all test fix
+
+all: fix test
+
+# Run tests
+test:
+	bundle exec rake test
+
+# Fix code formatting
+fix:
+	bundle exec standardrb --fix
+
+# Install dependencies
+install:
+	bundle install
+
+# Run both fix and test
+check: fix test
diff --git a/README.md b/README.md
index b5ec516..09f0742 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ A **Ruby** Integration for [Transloadit](https://transloadit.com)'s file uploadi
 
 This is a **Ruby** SDK to make it easy to talk to the [Transloadit](https://transloadit.com) REST API.
 
-*If you run Ruby on Rails and are looking to integrate with the browser for file uploads, checkout the [rails-sdk](https://github.com/transloadit/rails-sdk).*
+_If you run Ruby on Rails and are looking to integrate with the browser for file uploads, checkout the [rails-sdk](https://github.com/transloadit/rails-sdk)._
 
 ## Install
 
@@ -29,14 +29,14 @@ $ irb -rubygems
 => true
 ```
 
-Then create a Transloadit instance, which will maintain your 
-[authentication credentials](https://transloadit.com/accounts/credentials) 
+Then create a Transloadit instance, which will maintain your
+[authentication credentials](https://transloadit.com/accounts/credentials)
 and allow us to make requests to [the API](https://transloadit.com/docs/api/).
 
 ```ruby
 transloadit = Transloadit.new(
-  :key    => 'YOUR_TRANSLOADIT_KEY',
-  :secret => 'YOUR_TRANSLOADIT_SECRET'
+  :key    => 'MY_TRANSLOADIT_KEY',
+  :secret => 'MY_TRANSLOADIT_SECRET'
 )
 ```
 
@@ -49,8 +49,8 @@ and store the result on [Amazon S3](https://aws.amazon.com/s3/).
 require 'transloadit'
 
 transloadit = Transloadit.new(
-  :key    => 'YOUR_TRANSLOADIT_KEY',
-  :secret => 'YOUR_TRANSLOADIT_SECRET'
+  :key    => 'MY_TRANSLOADIT_KEY',
+  :secret => 'MY_TRANSLOADIT_SECRET'
 )
 
 # First, we create two steps: one to resize the image to 320x240, and another to
@@ -60,9 +60,9 @@ resize = transloadit.step 'resize', '/image/resize',
   :height => 240
 
 store  = transloadit.step 'store', '/s3/store',
-  :key    => 'YOUR_AWS_KEY',
-  :secret => 'YOUR_AWS_SECRET',
-  :bucket => 'YOUR_S3_BUCKET'
+  :key    => 'MY_AWS_KEY',
+  :secret => 'MY_AWS_SECRET',
+  :bucket => 'MY_S3_BUCKET'
 
 # Now that we have the steps, we create an assembly (which is just a request to
 # process a file or set of files) and let Transloadit do the rest.
@@ -125,7 +125,7 @@ API at the time the <dfn>Assembly</dfn> was created. You have to explicitly ask
 # reloads the response's contents from the REST API
 response.reload!
 
-# reloads once per second until all processing is finished, up to number of 
+# reloads once per second until all processing is finished, up to number of
 # times specified in :tries option, otherwise will raise ReloadLimitReached
 response.reload_until_finished! tries: 300 # default is 600
 ```
@@ -147,8 +147,8 @@ than one file in the same request. You can also pass a single <dfn>Step</dfn> fo
 require 'transloadit'
 
 transloadit = Transloadit.new(
-  :key    => 'YOUR_TRANSLOADIT_KEY',
-  :secret => 'YOUR_TRANSLOADIT_SECRET'
+  :key    => 'MY_TRANSLOADIT_KEY',
+  :secret => 'MY_TRANSLOADIT_SECRET'
 )
 
 assembly = transloadit.assembly(steps: store)
@@ -160,7 +160,7 @@ response = assembly.create!(
 )
 ```
 
-You can also pass an array of files to the `create!` method. 
+You can also pass an array of files to the `create!` method.
 Just unpack the array using the splat `*` operator.
 
 ```ruby
@@ -178,8 +178,8 @@ simply need to `use` other <dfn>Steps</dfn>. Following
 require 'transloadit'
 
 transloadit = Transloadit.new(
-  :key    => 'YOUR_TRANSLOADIT_KEY',
-  :secret => 'YOUR_TRANSLOADIT_SECRET'
+  :key    => 'MY_TRANSLOADIT_KEY',
+  :secret => 'MY_TRANSLOADIT_SECRET'
 )
 
 encode = transloadit.step 'encode', '/video/encode', { ... }
@@ -208,17 +208,17 @@ for recurring encoding tasks. In order to use these do the following:
 require 'transloadit'
 
 transloadit = Transloadit.new(
-  :key    => 'YOUR_TRANSLOADIT_KEY',
-  :secret => 'YOUR_TRANSLOADIT_SECRET'
+  :key    => 'MY_TRANSLOADIT_KEY',
+  :secret => 'MY_TRANSLOADIT_SECRET'
 )
 
 transloadit.assembly(
-  :template_id => 'YOUR_TEMPLATE_ID'
+  :template_id => 'MY_TEMPLATE_ID'
 ).create! open('/PATH/TO/FILE.mpg')
 ```
 
 You can use your steps together with this template and even use variables.
-The [Transloadit documentation](https://transloadit.com/docs/#passing-variables-into-a-template) 
+The [Transloadit documentation](https://transloadit.com/docs/#passing-variables-into-a-template)
 has some nice examples for that.
 
 ### 5. Using fields
@@ -231,8 +231,8 @@ to the upload itself. You can use fields like the following:
 require 'transloadit'
 
 transloadit = Transloadit.new(
-  :key    => 'YOUR_TRANSLOADIT_KEY',
-  :secret => 'YOUR_TRANSLOADIT_SECRET'
+  :key    => 'MY_TRANSLOADIT_KEY',
+  :secret => 'MY_TRANSLOADIT_SECRET'
 )
 
 transloadit.assembly(
@@ -252,8 +252,8 @@ a Notify URL for the <dfn>Assembly</dfn>.
 require 'transloadit'
 
 transloadit = Transloadit.new(
-  :key    => 'YOUR_TRANSLOADIT_KEY',
-  :secret => 'YOUR_TRANSLOADIT_SECRET'
+  :key    => 'MY_TRANSLOADIT_KEY',
+  :secret => 'MY_TRANSLOADIT_SECRET'
 )
 
 transloadit.assembly(
@@ -271,8 +271,8 @@ Transloadit also provides methods to retrieve/replay <dfn>Assemblies</dfn> and t
 require 'transloadit'
 
 transloadit = Transloadit.new(
-  :key    => 'YOUR_TRANSLOADIT_KEY',
-  :secret => 'YOUR_TRANSLOADIT_SECRET'
+  :key    => 'MY_TRANSLOADIT_KEY',
+  :secret => 'MY_TRANSLOADIT_SECRET'
 )
 
 assembly = transloadit.assembly
@@ -281,10 +281,10 @@ assembly = transloadit.assembly
 assembly.list
 
 # returns a specific assembly
-assembly.get 'YOUR_ASSEMBLY_ID'
+assembly.get 'MY_ASSEMBLY_ID'
 
 # replays a specific assembly
-response = assembly.replay 'YOUR_ASSEMBLY_ID'
+response = assembly.replay 'MY_ASSEMBLY_ID'
 # should return true if assembly is replaying and false otherwise.
 response.replaying?
 
@@ -292,7 +292,7 @@ response.replaying?
 assembly.get_notifications
 
 # replays an assembly notification
-assembly.replay_notification 'YOUR_ASSEMBLY_ID'
+assembly.replay_notification 'MY_ASSEMBLY_ID'
 ```
 
 ### 8. Templates
@@ -304,8 +304,8 @@ for recurring encoding tasks. Here's how you would create a <dfn>Template</dfn>:
 require 'transloadit'
 
 transloadit = Transloadit.new(
-  :key    => 'YOUR_TRANSLOADIT_KEY',
-  :secret => 'YOUR_TRANSLOADIT_SECRET'
+  :key    => 'MY_TRANSLOADIT_KEY',
+  :secret => 'MY_TRANSLOADIT_SECRET'
 )
 
 template = transloadit.template
@@ -331,8 +331,8 @@ There are also some other methods to retrieve, update and delete a <dfn>Template
 require 'transloadit'
 
 transloadit = Transloadit.new(
-  :key    => 'YOUR_TRANSLOADIT_KEY',
-  :secret => 'YOUR_TRANSLOADIT_SECRET'
+  :key    => 'MY_TRANSLOADIT_KEY',
+  :secret => 'MY_TRANSLOADIT_SECRET'
 )
 
 template = transloadit.template
@@ -341,11 +341,11 @@ template = transloadit.template
 template.list
 
 # returns a specific template.
-template.get 'YOUR_TEMPLATE_ID'
+template.get 'MY_TEMPLATE_ID'
 
 # updates the template whose id is specified.
 template.update(
-  'YOUR_TEMPLATE_ID',
+  'MY_TEMPLATE_ID',
   :name => 'CHANGED_TEMPLATE_NAME',
   :template => {
     :steps => {
@@ -358,7 +358,7 @@ template.update(
 )
 
 # deletes a specific template
-template.delete 'YOUR_TEMPLATE_ID'
+template.delete 'MY_TEMPLATE_ID'
 ```
 
 ### 9. Getting Bill reports
@@ -370,8 +370,8 @@ you can use the `bill` method passing the required month and year like the follo
 require 'transloadit'
 
 transloadit = Transloadit.new(
-  :key    => 'YOUR_TRANSLOADIT_KEY',
-  :secret => 'YOUR_TRANSLOADIT_SECRET'
+  :key    => 'MY_TRANSLOADIT_KEY',
+  :secret => 'MY_TRANSLOADIT_SECRET'
 )
 
 # returns bill report for February, 2016.
@@ -380,7 +380,48 @@ transloadit.bill(2, 2016)
 
 Not specifying the `month` or `year` would default to the current month or year.
 
-### 10. Rate limits
+### 10. Signing Smart CDN URLs
+
+You can generate signed [Smart CDN](https://transloadit.com/services/content-delivery/) URLs using your Transloadit instance:
+
+```ruby
+require 'transloadit'
+
+transloadit = Transloadit.new(
+  :key    => 'MY_TRANSLOADIT_KEY',
+  :secret => 'MY_TRANSLOADIT_SECRET'
+)
+
+# Generate a signed URL using instance credentials
+url = transloadit.signed_smart_cdn_url(
+  workspace: "MY_WORKSPACE",
+  template: "MY_TEMPLATE",
+  input: "avatars/jane.jpg"
+)
+
+# Add URL parameters
+url = transloadit.signed_smart_cdn_url(
+  workspace: "MY_WORKSPACE",
+  template: "MY_TEMPLATE",
+  input: "avatars/jane.jpg",
+  url_params: {
+    width: 100,
+    height: 200
+  }
+)
+
+# Set expiration time
+url = transloadit.signed_smart_cdn_url(
+  workspace: "MY_WORKSPACE",
+  template: "MY_TEMPLATE",
+  input: "avatars/jane.jpg",
+  expire_at_ms: 1732550672867  # Specific timestamp
+)
+```
+
+The generated URL will be signed using your Transloadit credentials and can be used to access files through the Smart CDN in a secure manner.
+
+### 11. Rate limits
 
 Transloadit enforces rate limits to guarantee that no customers are adversely affected by the usage
 of any given customer. See [Rate Limiting](https://transloadit.com/docs/api/#rate-limiting).
@@ -393,8 +434,8 @@ To change the number of attempts that will be made when creating an <dfn>Assembl
 require 'transloadit'
 
 transloadit = Transloadit.new(
-  :key    => 'YOUR_TRANSLOADIT_KEY',
-  :secret => 'YOUR_TRANSLOADIT_SECRET'
+  :key    => 'MY_TRANSLOADIT_KEY',
+  :secret => 'MY_TRANSLOADIT_SECRET'
 )
 
 # would make one extra attempt after a failed attempt.
@@ -423,3 +464,24 @@ Please see [ci.yml](https://github.com/transloadit/ruby-sdk/tree/main/.github/wo
 ### Ruby 2.x
 
 If you still need support for Ruby 2.x, 2.0.1 is the last version that supports it.
+
+## Contributing
+
+### Running tests
+
+```bash
+bundle install
+bundle exec rake test
+```
+
+To also test parity against the Node.js reference implementation, run:
+
+```bash
+TEST_NODE_PARITY=1 bundle exec rake test
+```
+
+To disable coverage reporting, run:
+
+```bash
+COVERAGE=0 bundle exec rake test
+```
diff --git a/lib/transloadit.rb b/lib/transloadit.rb
index d2a2869..9cda61d 100644
--- a/lib/transloadit.rb
+++ b/lib/transloadit.rb
@@ -1,5 +1,9 @@
 require "multi_json"
 require "date"
+require "json"
+require "openssl"
+require "uri"
+require "cgi"
 
 #
 # Implements the Transloadit REST API in Ruby. Check the {file:README.md README}
@@ -11,6 +15,7 @@ class Transloadit
   autoload :Exception, "transloadit/exception"
   autoload :Request, "transloadit/request"
   autoload :Response, "transloadit/response"
+  autoload :SmartCDN, "transloadit/smart_cdn"
   autoload :Step, "transloadit/step"
   autoload :Template, "transloadit/template"
   autoload :VERSION, "transloadit/version"
@@ -130,6 +135,54 @@ def to_json
     MultiJson.dump(to_hash)
   end
 
+  # @param workspace [String] Workspace slug
+  # @param template [String] Template slug or template ID
+  # @param input [String] Input value that is provided as `${fields.input}` in the template
+  # @param url_params [Hash] Additional parameters for the URL query string (optional)
+  # @param expire_at_ms [Integer] Expiration time as Unix timestamp in milliseconds (optional)
+  # @return [String] Signed Smart CDN URL
+  def signed_smart_cdn_url(
+    workspace:,
+    template:,
+    input:,
+    expire_at_ms: nil,
+    url_params: {}
+  )
+    raise ArgumentError, "workspace is required" if workspace.nil? || workspace.empty?
+    raise ArgumentError, "template is required" if template.nil? || template.empty?
+    raise ArgumentError, "input is required" if input.nil?
+
+    workspace_slug = CGI.escape(workspace)
+    template_slug = CGI.escape(template)
+    input_field = CGI.escape(input)
+
+    expire_at = expire_at_ms || (Time.now.to_i * 1000 + 60 * 60 * 1000) # 1 hour default
+
+    query_params = {}
+    url_params.each do |key, value|
+      next if value.nil?
+      Array(value).each do |val|
+        next if val.nil?
+        (query_params[key.to_s] ||= []) << val.to_s
+      end
+    end
+
+    query_params["auth_key"] = [key]
+    query_params["exp"] = [expire_at.to_s]
+
+    # Sort parameters to ensure consistent ordering
+    sorted_params = query_params.sort.flat_map do |key, values|
+      values.map { |v| "#{CGI.escape(key)}=#{CGI.escape(v)}" }
+    end.join("&")
+
+    string_to_sign = "#{workspace_slug}/#{template_slug}/#{input_field}?#{sorted_params}"
+
+    signature = OpenSSL::HMAC.hexdigest("sha256", secret, string_to_sign)
+
+    final_params = "#{sorted_params}&sig=#{CGI.escape("sha256:#{signature}")}"
+    "https://#{workspace_slug}.tlcdn.com/#{template_slug}/#{input_field}?#{final_params}"
+  end
+
   private
 
   #
diff --git a/test/test_helper.rb b/test/test_helper.rb
index ae9fa98..8ff789f 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -1,7 +1,7 @@
 $:.unshift File.dirname(__FILE__)
 $:.unshift File.expand_path("../../lib", __FILE__)
 
-if ENV["COVERAGE"] != "false"
+if ENV["COVERAGE"] != "0"
   require "simplecov"
   SimpleCov.start { add_filter "/test/" }
 end
diff --git a/test/unit/transloadit/node-smartcdn-sig.ts b/test/unit/transloadit/node-smartcdn-sig.ts
new file mode 100644
index 0000000..14c9461
--- /dev/null
+++ b/test/unit/transloadit/node-smartcdn-sig.ts
@@ -0,0 +1,89 @@
+#!/usr/bin/env tsx
+// Reference Smart CDN (https://transloadit.com/services/content-delivery/) Signature implementation
+// And CLI tester to see if our SDK's implementation
+// matches Node's
+
+/// <reference types="node" />
+
+import { createHash, createHmac } from 'crypto'
+
+interface SmartCDNParams {
+  workspace: string
+  template: string
+  input: string
+  expire_at_ms?: number
+  auth_key?: string
+  auth_secret?: string
+  url_params?: Record<string, any>
+}
+
+function signSmartCDNUrl(params: SmartCDNParams): string {
+  const {
+    workspace,
+    template,
+    input,
+    expire_at_ms,
+    auth_key = 'my-key',
+    auth_secret = 'my-secret',
+    url_params = {},
+  } = params
+
+  if (!workspace) throw new Error('workspace is required')
+  if (!template) throw new Error('template is required')
+  if (input === null || input === undefined)
+    throw new Error('input must be a string')
+
+  const workspaceSlug = encodeURIComponent(workspace)
+  const templateSlug = encodeURIComponent(template)
+  const inputField = encodeURIComponent(input)
+
+  const expireAt = expire_at_ms ?? Date.now() + 60 * 60 * 1000 // 1 hour default
+
+  const queryParams: Record<string, string[]> = {}
+
+  // Handle url_params
+  Object.entries(url_params).forEach(([key, value]) => {
+    if (value === null || value === undefined) return
+    if (Array.isArray(value)) {
+      value.forEach((val) => {
+        if (val === null || val === undefined) return
+        ;(queryParams[key] ||= []).push(String(val))
+      })
+    } else {
+      queryParams[key] = [String(value)]
+    }
+  })
+
+  queryParams.auth_key = [auth_key]
+  queryParams.exp = [String(expireAt)]
+
+  // Sort parameters to ensure consistent ordering
+  const sortedParams = Object.entries(queryParams)
+    .sort()
+    .map(([key, values]) =>
+      values.map((v) => `${encodeURIComponent(key)}=${encodeURIComponent(v)}`)
+    )
+    .flat()
+    .join('&')
+
+  const stringToSign = `${workspaceSlug}/${templateSlug}/${inputField}?${sortedParams}`
+  const signature = createHmac('sha256', auth_secret)
+    .update(stringToSign)
+    .digest('hex')
+
+  const finalParams = `${sortedParams}&sig=${encodeURIComponent(
+    `sha256:${signature}`
+  )}`
+  return `https://${workspaceSlug}.tlcdn.com/${templateSlug}/${inputField}?${finalParams}`
+}
+
+// Read JSON from stdin
+let jsonInput = ''
+process.stdin.on('data', (chunk) => {
+  jsonInput += chunk
+})
+
+process.stdin.on('end', () => {
+  const params = JSON.parse(jsonInput)
+  console.log(signSmartCDNUrl(params))
+})
diff --git a/test/unit/transloadit/test_smart_cdn.rb b/test/unit/transloadit/test_smart_cdn.rb
new file mode 100644
index 0000000..586eaa7
--- /dev/null
+++ b/test/unit/transloadit/test_smart_cdn.rb
@@ -0,0 +1,169 @@
+require "test_helper"
+require "json"
+require "open3"
+
+describe Transloadit do
+  before do
+    @auth_key = "my-key"
+    @auth_secret = "my-secret"
+    @transloadit = Transloadit.new(key: @auth_key, secret: @auth_secret)
+    @workspace = "my-app"
+    @template = "test-smart-cdn"
+    @input = "inputs/prinsengracht.jpg"
+    @expire_at = 1732550672867
+  end
+
+  def run_node_script(params)
+    return unless ENV["TEST_NODE_PARITY"] == "1"
+    script_path = File.expand_path("./node-smartcdn-sig", __dir__)
+    json_input = JSON.dump(params)
+    stdout, stderr, status = Open3.capture3("tsx #{script_path}", stdin_data: json_input)
+    raise "Node script failed: #{stderr}" unless status.success?
+    stdout.strip
+  end
+
+  describe "#signed_smart_cdn_url" do
+    it "requires workspace" do
+      assert_raises ArgumentError, "workspace is required" do
+        @transloadit.signed_smart_cdn_url(
+          workspace: nil,
+          template: @template,
+          input: @input
+        )
+      end
+
+      assert_raises ArgumentError, "workspace is required" do
+        @transloadit.signed_smart_cdn_url(
+          workspace: "",
+          template: @template,
+          input: @input
+        )
+      end
+    end
+
+    it "requires template" do
+      assert_raises ArgumentError, "template is required" do
+        @transloadit.signed_smart_cdn_url(
+          workspace: @workspace,
+          template: nil,
+          input: @input
+        )
+      end
+
+      assert_raises ArgumentError, "template is required" do
+        @transloadit.signed_smart_cdn_url(
+          workspace: @workspace,
+          template: "",
+          input: @input
+        )
+      end
+    end
+
+    it "requires input" do
+      assert_raises ArgumentError, "input is required" do
+        @transloadit.signed_smart_cdn_url(
+          workspace: @workspace,
+          template: @template,
+          input: nil
+        )
+      end
+    end
+
+    it "allows empty input string" do
+      params = {
+        workspace: @workspace,
+        template: @template,
+        input: "",
+        expire_at_ms: @expire_at
+      }
+      expected_url = "https://my-app.tlcdn.com/test-smart-cdn/?auth_key=my-key&exp=1732550672867&sig=sha256%3Ad5e13df4acde8d4aaa0f34534489e54098b5128c54392600ed96dd77669a533e"
+
+      url = @transloadit.signed_smart_cdn_url(**params)
+      assert_equal expected_url, url
+
+      if (node_url = run_node_script(params.merge(auth_key: "my-key", auth_secret: "my-secret")))
+        assert_equal expected_url, node_url
+      end
+    end
+
+    it "uses instance credentials" do
+      params = {
+        workspace: @workspace,
+        template: @template,
+        input: @input,
+        expire_at_ms: @expire_at
+      }
+      expected_url = "https://my-app.tlcdn.com/test-smart-cdn/inputs%2Fprinsengracht.jpg?auth_key=my-key&exp=1732550672867&sig=sha256%3A8620fc2a22aec6081cde730b7f3f29c0d8083f58a68f62739e642b3c03709139"
+
+      url = @transloadit.signed_smart_cdn_url(**params)
+      assert_equal expected_url, url
+
+      if (node_url = run_node_script(params.merge(auth_key: "my-key", auth_secret: "my-secret")))
+        assert_equal expected_url, node_url
+      end
+    end
+
+    it "includes empty width parameter" do
+      params = {
+        workspace: @workspace,
+        template: @template,
+        input: @input,
+        expire_at_ms: @expire_at,
+        url_params: {
+          width: "",
+          height: 200
+        }
+      }
+      expected_url = "https://my-app.tlcdn.com/test-smart-cdn/inputs%2Fprinsengracht.jpg?auth_key=my-key&exp=1732550672867&height=200&width=&sig=sha256%3Aebf562722c504839db97165e657583f74192ac4ab580f1a0dd67d3d868b4ced3"
+
+      url = @transloadit.signed_smart_cdn_url(**params)
+      assert_equal expected_url, url
+
+      if (node_url = run_node_script(params.merge(auth_key: "my-key", auth_secret: "my-secret")))
+        assert_equal expected_url, node_url
+      end
+    end
+
+    it "handles nil values in parameters" do
+      params = {
+        workspace: @workspace,
+        template: @template,
+        input: @input,
+        expire_at_ms: @expire_at,
+        url_params: {
+          width: nil,
+          height: 200
+        }
+      }
+      expected_url = "https://my-app.tlcdn.com/test-smart-cdn/inputs%2Fprinsengracht.jpg?auth_key=my-key&exp=1732550672867&height=200&sig=sha256%3Ad6897a0cb527a14eaab13c54b06f53527797c553d8b7e5d0b1a5df237212f083"
+
+      url = @transloadit.signed_smart_cdn_url(**params)
+      assert_equal expected_url, url
+
+      if (node_url = run_node_script(params.merge(auth_key: "my-key", auth_secret: "my-secret")))
+        assert_equal expected_url, node_url
+      end
+    end
+
+    it "handles array values in parameters" do
+      params = {
+        workspace: @workspace,
+        template: @template,
+        input: @input,
+        expire_at_ms: @expire_at,
+        url_params: {
+          tags: ["landscape", "amsterdam", nil, ""],
+          height: 200
+        }
+      }
+      expected_url = "https://my-app.tlcdn.com/test-smart-cdn/inputs%2Fprinsengracht.jpg?auth_key=my-key&exp=1732550672867&height=200&tags=landscape&tags=amsterdam&tags=&sig=sha256%3Aff46eb0083d64b250b2e4510380e333f67da855b2401493dee7a706a47957d3f"
+
+      url = @transloadit.signed_smart_cdn_url(**params)
+      assert_equal expected_url, url
+
+      if (node_url = run_node_script(params.merge(auth_key: "my-key", auth_secret: "my-secret")))
+        assert_equal expected_url, node_url
+      end
+    end
+  end
+end