MCP Inspector

MCP Inspector is a developer tool for testing the Model Context Protocol servers that connect AI applications to tools and data. It lets you examine server behavior directly, without testing every interaction through an AI chat application.

• Browser inspection: Use a graphical interface to inspect a server while a monitoring sidebar displays protocol traffic.
• Tool testing: List available tools, send test inputs, and examine responses from local servers or remote HTTP endpoints.
• Automated checks: The command-line client returns machine-readable results for CI, shell pipelines, and coding agents.
• Interactive terminal: Test servers through a terminal interface when you don't want to use a browser.

The clients share connection behavior, configuration files, and OAuth state, and support both legacy and modern MCP protocol behavior. Inspector runs locally with Node.js; its browser interface uses a local backend. Requests to a remote server go to that endpoint.

Inspector stores secrets in the OS keychain by default when one is available. Without a keychain, it falls back to an unencrypted local file unless you supply an encryption key. It also supports keeping secrets only in memory.