add openai responses api

fern/sdk/mcp-server.mdx

@@ -148,6 +148,52 @@ The Vapi MCP Server exposes these actions as MCP tools:
     ```
 
   </Tab>
+  <Tab title="OpenAI responses API">
+    <Note>
+      The OpenAI <code>responses</code> API now supports MCP. <a href="https://platform.openai.com/docs/guides/tools-remote-mcp#page-top" target="_blank" rel="noopener">Read more here</a>.
+    </Note>
+    <CodeBlocks>
+    ```typescript title="typescript"
+    import OpenAI from 'openai';
+    // Replace with your actual OpenAI API key
+    const openai = new OpenAI({ apiKey: 'YOUR_OPENAI_API_KEY' });
+    async function main() {
+      const response = await openai.responses.create({
+        model: 'gpt-4.1',
+        tools: [
+          {
+            type: 'mcp',
+            server_label: 'vapi-mcp',
+            server_url: 'https://mcp.vapi.ai/mcp',
+            headers: { "Authorization": "Bearer YOUR_VAPI_API_KEY" }
+          },
+        ],
+        input: 'What vapi tools do you have available?',
+      });
+      console.dir(response, { depth: null });
+    }
+    main();
+    ```
+    ```python title="python"
+    import openai
+    # Replace with your actual OpenAI API key
+    openai.api_key = 'YOUR_OPENAI_API_KEY'
+    response = openai.responses.create(
+        model="gpt-4.1",
+        tools=[
+            {
+                "type": "mcp",
+                "server_label": "vapi-mcp",
+                "server_url": "https://mcp.vapi.ai/mcp",
+                "headers": {"Authorization": "Bearer YOUR_VAPI_API_KEY"}
+            },
+        ],
+        input="What vapi tools do you have available?",
+    )
+    print(response)
+    ```
+    </CodeBlocks>
+  </Tab>
   <Tab title="Local">
     Run the MCP server on your own machine for development or testing.