The Wireshark of AI

Debug MCP Traffic.
Instantly.

A native desktop inspector for Model Context Protocol JSON-RPC. Live capture, replay, diff, and export across stdio, HTTP, and SSE — with zero changes to your servers or clients.

stdio http sse windows free tier
Download Free See Pricing →

No data leaves your machine on Free and Pro.

What it does

Everything you'd want from a protocol inspector

Built for developers who are tired of adding console.log to their MCP server source and hoping for the best.

capture

Live Inspect

Every JSON-RPC message, both directions, as it happens. Transparent MITM — your client and server need zero modification.

replay

Re-execute Any Call

Pick any captured request and fire it again against the live server. See the new response side-by-side with the original.

diff

Visual Diff

Compare any two traces — params, results, or errors — with a collapsible JSON diff. Catch response shape changes before they hit production.

export

Share Sessions

Save any session as a .mcp-trace file. Attach to a bug report. Open on any machine running MCP Inspector.

timeline

Latency at a Glance

Color-coded timeline shows every call status — in-flight, done, slow (≥200ms), or error. Find the bottleneck without reading logs.

on-prem

Air-Gap Safe

Free and Pro run entirely locally. No telemetry, no cloud sync. Team tier: self-hosted aggregator on your own infrastructure.

Pricing

Start free. Pay when it earns it.

The free tier is a real product, not a demo. Use it indefinitely. Upgrade when you need replay, diff, or team visibility.

Free

$0

Portable .exe. No install, no account. One command captures live MCP traffic.

  • 100-trace ring buffer per session
  • stdio + HTTP + SSE capture
  • Live timeline with latency
  • Server auto-discovery
  • Session replay
  • Diff view
  • Trace export
  • SQLite persistence
Download .exe
Most Popular

Pro

$79 /month

Everything in Free, plus unlimited history, replay, diff, and export. Two machine licenses.

  • Unlimited trace history (SQLite)
  • Session replay
  • Visual diff (side-by-side JSON)
  • Export as .mcp-trace
  • Unlimited simultaneous proxies
  • Custom server config
  • 2 machine licenses
  • Email support
Get Pro → or save 17% with annual billing →

Team

$69 /seat/month

Self-hosted aggregator on your infrastructure. Every developer sees every agent's traffic on a shared dashboard. Min 3 seats.

  • All Pro features
  • Central aggregator (self-hosted)
  • Web dashboard for shared visibility
  • Org-managed seat licensing
  • Free unlimited MICTs (tracers)
  • Priority support
  • Annual billing option (save 17%)
Get Team →

Enterprise: self-hosted license server, SSO/SAML, audit logs, air-gap mode. Contact us →

FAQ

Common questions

Does MCP Inspector send my traffic to the cloud?
No. On Free and Pro, every trace stays on your machine — written to SQLite locally or kept in memory. On Team, you run your own aggregator on your own server; we host nothing except the license validation API. Enterprise self-hosted mode has zero phone-home.
What MCP transports does it support?
All three: stdio (subprocess wrap), http (direct streamable-HTTP), and sse (legacy SSE transport). The reverse proxy handles SSE and HTTP; the MITM wrapper handles stdio. You pick based on how your server runs.
Do I need to change my MCP server or client code?
No. The inspector sits between your client and server transparently — for stdio, it wraps the server subprocess; for HTTP/SSE, it runs a local reverse proxy. The client talks to MCP Inspector, which forwards to your server. Neither side knows it's there.
What platforms does it run on?
The desktop app currently ships for Windows (64-bit). macOS and Linux builds are planned. The CLI proxy (mcp-inspector) runs on any platform where Python 3.11+ is available.
How does the Team tier aggregator work?
You run our aggregator service (a Docker image: PostgreSQL + aiohttp relay) on any server on your network. Each developer machine runs a free lightweight tracer (MICT) that intercepts local MCP traffic and posts it to your aggregator. The web dashboard at your aggregator URL shows all agents' traffic live, filterable by machine and session. No traffic leaves your network.