Product / UX / Agent tools & protocols

MCP Inspector

Developer tool for testing and debugging MCP servers. Ships three clients from one binary - a React web UI, a scriptable CLI for automation and CI, and an Ink terminal UI - over stdio, SSE and Streamable-HTTP, with OAuth including discovery and mid-session recovery, multi-server config, and DNS-rebinding protection.

The repository carries no LICENSE file; the terms are declared in the README and in package.json, which is what the openness axis reads. Verified 2026-08-13 via GitHub, the README and package.json.

Openness

5 high confidence

5.0

license: MIT(OSI)
source: public
core-gated: ungated

Fully MIT, no feature-gated core. There is no LICENSE file in the repository at all; MIT is stated in the README's License section and in package.json ("license": "MIT"). Worth noting beside the sibling repos: typescript-sdk and servers have both moved to the MCP Apache-2.0 transition license and this one has not, so the org is no longer uniform. The whole tool is in the published tree and runs via `npx @modelcontextprotocol/inspector` with no key or paid tier.

https://raw.githubusercontent.com/modelcontextprotocol/inspector/main/README.md recorded 2026-08-13
License section reads, in full - "MIT." The repository root carries no LICENSE file; raw.githubusercontent answers 404 for both main/LICENSE and main/LICENSE.md.
https://raw.githubusercontent.com/modelcontextprotocol/inspector/main/package.json recorded 2026-08-13
"license": "MIT" - the machine-readable declaration, agreeing with the README.
https://github.com/modelcontextprotocol/inspector recorded 2026-08-13
Repo page, 10,660 stargazers. Web, CLI and TUI clients plus shared core all in the tree, run from one `npx @modelcontextprotocol/inspector` binary. No paid tier, license key or enterprise directory.

Adoption

3 high confidence

3.0

905,396 npm downloads of @modelcontextprotocol/inspector in the trailing 30 days, which bands at 100K-1M, level 3 on the software adoption scale. This is the reference MCP debugging tool, sitting just under the 1M boundary.

https://api.npmjs.org/downloads/point/last-month/@modelcontextprotocol/inspector recorded 2026-08-12
905,396 downloads in the trailing 30 days for @modelcontextprotocol/inspector

Capability

4 high confidence

4.0

Best-in-class for its debugging niche; narrower scope than the SDKs by design.

https://raw.githubusercontent.com/modelcontextprotocol/inspector/main/README.md recorded 2026-08-13
"three ways to inspect a server: Web - a Vite + React + Mantine single-page app with a Node backend. CLI - a scriptable command-line client for automation, CI, and fast agent feedback loops. TUI - an interactive terminal UI built with Ink." core/auth covers "OAuth: providers, discovery, storage, mid-session recovery". A streamable-HTTP server can serve the modern 2026-07-28 protocol era or dual-era. NOT on the page: request history or visualization.
https://github.com/modelcontextprotocol/inspector recorded 2026-08-13
Repo page for the same README.

Verified 2026-08-12