MCPJam Inspector

MCPJamis the open-sourcetesting & evaluations platform for MCP server developerswho ship. Interactively test tools, prompts, resources, and authorization across 16 client configurations and 170+ models. Run evals on test cases, get insights on what's breaking, and gate regressions to secure every deployment.

... or run MCPJam locally for HTTP/S and local STDIO servers:

Clients like ChatGPT, Claude, and Cursor all read your server differently. MCPJam catches those differences, shows where your server breaks, and tells you how to fix it:

- Inspect & debug: Explore your server's tools, resources, and prompts in one place. Test prompts from real LLMs, with full visibility & traces on every JSON-RPC message and OAuth exchange.
- Cross-client evals: Score agent behavior across 16 client configurations — ChatGPT, Claude, Cursor, Copilot, and more — to understand how your MCP integrations perform across all users. Track accuracy, latency, and tool-call performance over time.
- Security & reliability: Automate conformance & behavior checks in CI/CD to catch regressions before they reach production.

Debug your server against a model using tool calls or in-panel chat, with Chat, Trace, and Raw views. Supports the OpenAI Apps SDK and MCP app UIs, text tools, and a Chrome DevTools-style widget emulator so you can iterate on widgets locally.

- Invoke a tool to render its widget instantly, or drive your server with an LLM.
- Watch all JSON-RPC andwindow.openaimessages in the logs.
- Switch the emulator between Desktop, Tablet, and Mobile.
- Test locale changes, CSP permissions, light/dark mode, hover & touch, and safe-area insets.

Trace view: every tool call, agent step, and JSON-RPC message in one timeline.

Multi-server chat on frontier models for free, or bring your own API key. Chat, Trace, and Raw views; compare up to 3 models side by side and watch each server's token usage.

Guided MCP OAuth conformance checks with step-by-step explanations. Test against every version of the OAuth spec (2025-03-26, 2025-06-18, 2025-11-25, and the 2026-07-28 draft), with support for client pre-registration, Dynamic Client Registration (DCR), and Client ID Metadata Documents (CIMD).

Everything you need to test an MCP server by hand: run tools, resources, resource templates, prompts, and elicitation flows with full JSON-RPC observability. Every feature of the original inspector, and more.

Use Skills in Chat and Playground to extend models with reusable behaviors. Local skills are read from your filesystem and never leave your machine; a project can also carry hosted skills, available on accounts where that is enabled.Read more

Group servers into shared workspaces with real-time team sync, so everyone on your team tests against the same configuration.Read more

Define test cases with expected tool calls and run them across multiple LLMs. Track accuracy over time to catch regressions early and improve your server with every iteration.Read more

Run MCPJam from the terminal for fast local dev loops and CI. Probe servers, run OAuth checks, inspect tools and resources, and execute evals without leaving your shell.Read more

Programmatic access to MCPJam for custom tooling, scripting, and integrations. Build your own workflows on top of MCPJam's inspection and evaluation primitives.Read more

Wire MCPJam into GitHub Actions, GitLab CI, or any CI system to run conformance, E2E tests, and evals on every PR — and catch MCP server regressions before they ship.Read more

Hosted web app: Openapp.mcpjam.com. No install, always latest, and you can share server links with teammates like a Google Doc. HTTPS server URLs only; no STDIO, tunneling, skills, or tasks (those need the local inspector).Hosted docs

Desktop app: Download the installer. Supports HTTP/S and local STDIO, no Node.js required.Install Mac·Install Windows

git clone https://github.com/MCPJam/inspector.git cd inspector docker build -t mcpjam/mcp-inspector:local -f mcpjam-inspector/Dockerfile . docker run -p 127.0.0.1:6274:6274 mcpjam/mcp-inspector:local

We're grateful you're considering it. Read thecontributing guideto get started, and come say hi inDiscord.

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Licensed under theApache License 2.0. SeeLICENSE.

Bring agent evaluations, observability, and synthetic test set generation directly into your IDE for free with Galileo's new MCP server