A protocol-aware debugger for MCP sessions.
Inspect tool list negotiation, request/response framing, and session state — without piping JSON-RPC into a terminal.
No credit card required · Free plan available
Tool registry
Capabilities
tools, resources
{ "name": "refunds.create" }
{ "ok": true, "id": "re_3b" }
{ "uri": "memory://refund-policy" }
{ "code": -32601, "message": "method not found" }
What you actually get.
The MCP Debugger speaks the Model Context Protocol natively. Capture a live session, pin a session ID, and watch every tool registration, resource fetch, prompt response, and lifecycle event arrive with proper protocol decoding. No more squinting at hex frames or correlating IDs by hand.
- Native JSON-RPC framing with method-aware rendering
- Pinned session view with live state diffing
- Replay any session against a new MCP server build
- Surfaces protocol-level errors that generic debuggers miss
Built for the moments where minutes turn into hours.
Protocol-decoded view
Tool calls, resource reads, and prompt responses are rendered as first-class objects.
Session state inspector
See the live tool registry, capability set, and outstanding request map at any instant.
Reproducible sessions
Save a session, replay it against a new server build, and diff the responses.
What teams ship with this.
Real situations where mcp debugger replaces an afternoon of detective work with a single, decisive answer.
Ship mcp debugger this afternoon.
Start free, capture a live endpoint in seconds, and put the whole WebhookScout platform behind your integrations.