MCPJam Inspector
by the MCPJam team
Open-source testing, debugging and evaluation platform for MCP servers.
Repo: https://github.com/mcpjam/inspector (Apache-2.0, ~2.2k stars, ~292 forks at access time). Anthropic’s own reference debugger is the separate modelcontextprotocol/inspector. The earlier note called MCPJam “a fork of Anthropic’s inspector”; the GitHub page summary read this session did not show that, so the claim is treated as unverified.
Features (per repo README, 2026-09-30)
- Playground: cross-client chat with full JSON-RPC tracing; reported support for 16 client configurations and 170+ models
- Manual testing of tools, resources and prompts (STDIO, SSE, HTTP transports)
- OAuth debugger with conformance checks across protocol versions
- Evals: test cases with accuracy metrics across LLMs
- CLI and SDK for automation; GitHub Actions / CI integration
- Skills (reusable model behaviours) and team Workspaces with real-time sync
Getting started
npx @mcpjam/inspector@latest Also available as a hosted web app (app.mcpjam.com), desktop app, or Docker container.
Good for MCP server developers and ChatGPT-app builders who want to test locally. Related: model-context-protocol, chrome-devtools-mcp.
Sources
- https://github.com/mcpjam/inspector (accessed 2026-09-30)