Inspectr, from Inspectr Hq, is a free MCP server tool built with TypeScript/JavaScript, running on Node.js. It functions as an API proxy and HTTP inspection tool, designed for reviewing, analyzing, and debugging API requests, MCP server calls, and webhook events. It offers multiple distribution methods, including direct execution via npx, Homebrew installation, pre-compiled binaries, and Docker container images, making it accessible across various development environments.

What does Inspectr connect to?

Inspectr primarily connects to and acts as an API Proxy for HTTP-based API requests and webhook events. It is specifically designed to interact with MCP servers, allowing for the inspection and debugging of calls directed towards them, including those made by Large Language Models. While it can expose local AI models, explicit compatibility with specific AI clients is not detailed. Internally, it broadcasts data via Server-Sent Events when its embedded application mode is active.

Core features and tools

Inspectr provides a suite of tools for API management and debugging. These include Inspect API Requests, Analyze Webhook Events, API Proxy, Real-time Logging, History & Replay, and Public Exposure (Public tunnel). It also offers MCP Insights, a Rules Engine, Trace Grouping, Mock Backend (Mock APIs from OpenAPI), Guard Authentication, Response Overrides, Validation & Debugging, and the ability to Record and export to OpenAPI.

Who is it for?

Inspectr is designed for developers, QA engineers, and API teams who need to inspect, debug, and test API interactions. It helps in understanding API request flows and webhook payloads, and in simulating API behaviors. Its capabilities support various stages of the development and testing lifecycle. Skip this if your workflow does not involve HTTP API proxying or webhook event analysis.

How to get started

The server authenticates using an API key passed in the headers. This authentication layer, referred to as a "guard," secures proxied services, especially when publicly exposed, requiring a valid key or token.

Use cases

• Debugging during development by inspecting requests in real-time to identify malformed requests, missing parameters, or correlating problematic responses.
• Testing integrations and webhooks by capturing and reviewing payloads from third-party services to overcome outdated documentation.
• Mocking API backends by creating mocked services based on OpenAPI specifications for testing and development, or simulating API behavior with response overrides.

Inspectr is a valuable free tool for managing and debugging API interactions, particularly for MCP server environments. Its focus on real-time inspection, mocking, and authentication provides essential capabilities for development and testing. The ability to secure publicly exposed services with a guard authentication layer is a notable benefit.