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OpenWebhook MCP Tools for Cursor and Claude

Reference for OpenWebhook MCP tools: url.inspect, watch.start, and watch.wait. Cursor and Claude setup lives on dedicated pages.

By David Lorenzo García··6 min read

The OpenWebhook MCP server lets an AI coding agent print an inspect URL, watch incoming requests, and block until the next HTTP request arrives. The first run does not need an account. A Pro token unlocks permanent slugs. Nothing is written to stdout except JSON-RPC.

This page is the tool list and a generic loop. Product setup is on test webhooks in Cursor and test webhooks in Claude.

Install the public package:

npm install --global openwebhook

The server is listed as co.openwebhook/mcp in the MCP Registry and as a local stdio bundle on Smithery. npx -y openwebhook mcp starts it without a global install.

Tools

Tool Purpose
url.inspect Current anonymous ingest URL
watch.start Start an in-memory SSE buffer (anonymous, or a slug with Pro)
watch.stop Stop the stream and drop the buffer
watch.wait Block until the next event (timeout_ms, max 300000)
watch.list Events already in the local buffer
endpoint.list Permanent slugs on a Pro account
endpoint.create Create a custom slug (Pro)
endpoint.delete Delete by endpoint ID (Pro)

Payloads stay in the MCP process only. They are not written to disk.

A complete loop

  1. Ask the agent for url.inspect, then watch.start (no slug).
  2. Ask it to watch.wait with a 60 second timeout.
  3. In another terminal, POST to the URL it printed:
curl -X POST \
  'https://hooks.openwebhook.co/YOUR-UUID/probe' \
  -H 'content-type: application/json' \
  --data '{"from":"mcp"}'

The agent should return the method, path, headers and body.

When to use MCP versus the CLI

Use openwebhook listen --port when a real local HTTP server must receive the request. Use MCP when you want the payload inside the chat to write a handler, compare headers, or generate a test.

See Forward webhooks to localhost for the listen path.

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