diff --git a/cookbook/copilot-sdk/nodejs/accessibility-report.md b/cookbook/copilot-sdk/nodejs/accessibility-report.md
index 849dd726..786a4c16 100644
--- a/cookbook/copilot-sdk/nodejs/accessibility-report.md
+++ b/cookbook/copilot-sdk/nodejs/accessibility-report.md
@@ -90,7 +90,7 @@ async function main() {
     let idleResolve: (() => void) | null = null;
 
     session.on((event) => {
-        if (event.type === "assistant.message.delta") {
+        if (event.type === "assistant.message_delta") {
             process.stdout.write(event.data.deltaContent ?? "");
         } else if (event.type === "session.idle") {
             idleResolve?.();
@@ -179,7 +179,7 @@ main().catch(console.error);
 ## How it works
 
 1. **Playwright MCP server**: Configures a local MCP server running `@playwright/mcp` to provide browser automation tools
-2. **Streaming output**: Uses `streaming: true` and `assistant.message.delta` events for real-time token-by-token output
+2. **Streaming output**: Uses `streaming: true` and `assistant.message_delta` events for real-time token-by-token output
 3. **Accessibility snapshot**: Playwright's `browser_snapshot` tool captures the full accessibility tree of the page
 4. **Structured report**: The prompt engineers a consistent WCAG-aligned report format with emoji severity indicators
 5. **Test generation**: Optionally detects the project language and generates Playwright accessibility tests
@@ -212,7 +212,7 @@ Unlike `sendAndWait`, this recipe uses streaming for real-time output:
 
 ```typescript
 session.on((event) => {
-    if (event.type === "assistant.message.delta") {
+    if (event.type === "assistant.message_delta") {
         process.stdout.write(event.data.deltaContent ?? "");
     } else if (event.type === "session.idle") {
         idleResolve?.();
diff --git a/cookbook/copilot-sdk/nodejs/recipe/accessibility-report.ts b/cookbook/copilot-sdk/nodejs/recipe/accessibility-report.ts
index 28ab7aba..18e274a9 100644
--- a/cookbook/copilot-sdk/nodejs/recipe/accessibility-report.ts
+++ b/cookbook/copilot-sdk/nodejs/recipe/accessibility-report.ts
@@ -55,7 +55,7 @@ async function main() {
     let idleResolve: (() => void) | null = null;
 
     session.on((event) => {
-        if (event.type === "assistant.message.delta") {
+        if (event.type === "assistant.message_delta") {
             process.stdout.write(event.data.deltaContent ?? "");
         } else if (event.type === "session.idle") {
             idleResolve?.();
@@ -72,12 +72,12 @@ async function main() {
 
     const prompt = `
     Use the Playwright MCP server to analyze the accessibility of this webpage: ${url}
-    
+
     Please:
     1. Navigate to the URL using playwright-browser_navigate
     2. Take an accessibility snapshot using playwright-browser_snapshot
     3. Analyze the snapshot and provide a detailed accessibility report
-    
+
     Format the report EXACTLY like this structure with emoji indicators:
 
     📊 Accessibility Report: [Page Title] (domain.com)
@@ -133,8 +133,8 @@ async function main() {
         const detectLanguagePrompt = `
         Analyze the current working directory to detect the primary programming language used in this project.
         Look for project files like package.json, *.csproj, pom.xml, requirements.txt, go.mod, etc.
-        
-        Respond with ONLY the detected language name (e.g., "TypeScript", "JavaScript", "C#", "Python", "Java") 
+
+        Respond with ONLY the detected language name (e.g., "TypeScript", "JavaScript", "C#", "Python", "Java")
         and a brief explanation of why you detected it.
         If no project is detected, suggest "TypeScript" as the default for Playwright tests.
         `;
@@ -151,7 +151,7 @@ async function main() {
 
         const testGenerationPrompt = `
         Based on the accessibility report you just generated for ${url}, create Playwright accessibility tests in ${language}.
-        
+
         The tests should:
         1. Verify all the accessibility checks from the report
         2. Test for the issues that were found (to ensure they get fixed)
@@ -167,7 +167,7 @@ async function main() {
            - Touch targets meet minimum size requirements
         4. Use Playwright's accessibility testing features
         5. Include helpful comments explaining each test
-        
+
         Output the complete test file that can be saved and run.
         Use the Playwright MCP server tools if you need to verify any page details.
         `;