n8n · tool · fg-0352

n8n webhook returns 404 'The requested webhook is not registered' on the second call

404 The requested webhook "POST my-path" is not registered.

Verified 2026-10-15 · Confirmed by 0 builders · Trust 50/100

Cause

The webhook-test URL is registered only while the editor is listening and accepts a single call. The production URL exists only while the workflow is published or active, and its runs appear only in the Executions list.

Fix

Point external services at the production URL, publish the workflow, and read results in the Executions tab. Use the test URL only for one manual call at a time.

Apply

https://n8n.example.com/webhook/my-path      # production, needs the workflow published
https://n8n.example.com/webhook-test/my-path # one call after Listen for test event

Affects: n8n 1.x and 2.x self-hosted and Cloud, as of 2026-10

Sources

• https://docs.n8n.io/integrations/builtin/core-nodes/n8n-nodes-base.webhook/
• https://github.com/n8n-io/n8n/blob/master/packages/cli/src/errors/response-errors/webhook-not-found.error.ts

claude mcp add --transport http footgun https://getfootgun.com/api/mcp