Streamable HTTP

Start the server with HTTP selected explicitly:

npx mcp-failure-lab serve --transport http

The default endpoint is http://127.0.0.1:3000/mcp.

Configuration

Option	Default	Purpose
--transport	stdio	Select stdio or http.
--host	127.0.0.1	HTTP bind host.
--port	3000	HTTP listener port.
--path	/mcp	Streamable HTTP endpoint.

HTTP-specific options require --transport http. The host, port, and path are validated before the listener starts.

Protocol behavior

The endpoint serves MCP 2026-07-28 and provides stateless compatibility for 2025-11-25. Both paths use the same server factory and expose the same ping, delay, hang, and disconnect tools.

Calling disconnect terminates its active HTTP request instead of returning a normal tool result. The listener remains available for later requests.

Local security boundary

The default loopback bind is intentional. Failure Lab validates the request path and the Host and Origin headers. Wildcard bind addresses are rejected because the server does not provide authentication or TLS.

Use a trusted reverse proxy if you need authentication, TLS termination, or access from another machine. Do not expose the endpoint directly to an untrusted network.

MCP Inspector

Run the HTTP server and Inspector in separate terminals:

npx mcp-failure-lab serve --transport http

npx @modelcontextprotocol/inspector@latest

Add a Streamable HTTP server with URL http://127.0.0.1:3000/mcp. If Inspector 2.4 times out while calling tools in Modern mode, use Legacy mode for manual UI checks. Modern 2026-07-28 remains covered through the direct HTTP integration path.

Press Ctrl+C in the server terminal for graceful shutdown.