MCP trigger connection issue with VAPI AI

[Inshal_Amir]

i am tring to connect the mcp tool with vapi ai from n8n and today it is occurring problems http req 500 error

1. Tool id: cc4f16bb-f2af-434f-83e8-33316bc6bb67
2. Mcp url link: https://waitsmart.app.n8n.cloud/mcp/6114acac-a3aa-4404-8d1b-6640256c78f4/sse
3. Response Body error: {
   “error”: “Failed to connect to MCP server: SSE error: Failed to fetch”
   }
4. Request failed with status: 500

[cutecatcode]

Hi @Inshal_Amir, welcome to community!
If you’re in latest stable n8n version (1.102.x), you don’t need to add /sse path anymore.
Just remove the /sse path in your url, and hopefully your problem is gone.

Hope it helps, and kindly mark my message as solution, thanks:)

[Inshal_Amir]

not working

[cutecatcode]

Did you already activate the MCP workflow?

[Inshal_Amir]

yeah its active

[Noid]

Was there a fix for this ? Experience the same situation using the production link.

[Inshal_Amir]

Yes there is a solution for this, just follow these steps and your agent will work.

1. Update you n8n to the latest stable version.
2. Import the latest webhook.
3. Configure the settings of the webhook to : POST request and REspond to webhook. In the respond to webhook node in n8n , provide the correct JSON format as mentioned in the vapi ai docs.
4. Copy the production link and paste it into the vapi ai MCP tool.
5. Choose the connection type to SSL and set the timer to 30 seconds.
6. Set up rest of the tool configurations.
7. No need to test the MCP tool just go to the AI Assistant in vapi and attach the tool with it and call the tool within the system prompt with proper name.
8. I repeat no need to test the MCP tool during configuration. Just test it while calling the assistant properly.
9. You will see it will work and get the response for you if your n8n workflow works correctly.
10. If this works please mark it as a solution. I took me a while to type this all for you.