graceful-beige•5mo ago

MCP Server using N8n

I am trying to use the mcp tool in vapi using n8n mcp server I am getting the following error I am using the MCP Server Trigger in n8n I am not able to connect it to the server

7 Replies

Vapi Support Bot•5mo ago

Fix the "This webhook is not registered for POST" Error Ensure your endpoint is configured to accept POST requests. In your n8n webhook setup: 1. Verify the webhook URL in Vapi Dashboard matches exactly with your n8n webhook URL (no typos or spaces) 2. Test your endpoint manually with a tool like Postman using:

   curl -X POST <your_webhook_url> \
   -H "Content-Type: application/json" \
   -d '{"test": "data"}'

   curl -X POST <your_webhook_url> \
   -H "Content-Type: application/json" \
   -d '{"test": "data"}'

3. Check your server logs for any errors preventing the webhook from being called Sources: - Discord conversation about webhook errors - Discord conversation about webhook configuration

⤵️ Mention @Vapi Support Bot for follow-ups 🐥

Duckie•5mo ago

Message marked as helpful by @! AetherMind! 🎉

deep-jade•5mo ago

checking if this is resolved/solved for you?

graceful-beigeOP•5mo ago

hello @Kings_big💫 no it is not resolved yet

deep-jade•5mo ago

Make sure your n8n workflow with the MCP Server Trigger is active, use the production MCP URL, confirm authentication settings, and ensure SSE support in your reverse proxy. Also, verify that the Vapi uses the correct URL and headers, and consider testing the endpoint manually like, with curl to check connectivity.

exotic-emerald•4mo ago

same issue - tried curl POSt and it does generate an error - requires GET; but we dont control verm in n8n. is there a way to call it via GET in vapi?

Sahil•4mo ago

Hey, really sorry for your experiencel. If possible, could you record a loom video describing this error/behavior or inconsistency in the dashboard with the steps to reproduce it? That way, I can share this with my team, and we'll take a look. We'll even try to reproduce the same so we can fix it for you. Also, I'll request you to share your tool ID/call ID.

MCP Server using N8n

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