MCP Function App Tester

The MCP Function App Tester is a lightweight, TypeScript‑based server that bridges the gap between local Azure Function Apps and AI assistants such as Claude. By exposing a set of well‑defined MCP resources, the server allows an assistant to invoke HTTP endpoints directly from within its own workflow, eliminating the need for external tooling or manual curl commands. This capability is especially valuable during development and testing cycles, where rapid feedback on API behavior can accelerate iteration.

At its core, the server implements a suite of HTTP methods—GET, POST, PUT, and DELETE—that mirror typical RESTful interactions. Each request is represented as a JSON payload containing the method, endpoint path, optional headers, and body data for mutating operations. The server then forwards these requests to the local Function App runtime (defaulting to ) and returns detailed response information, including status codes, headers, and body content. This end‑to‑end roundtrip is handled entirely through the MCP protocol, making it consumable by any client that understands MCP.

Authentication is a key differentiator. The server supports three common schemes—Basic Authentication, Bearer Token, and API Key—configurable via environment variables. An explicit precedence hierarchy ensures that the most secure method available is automatically applied, reducing configuration errors. Developers can therefore test protected endpoints without hard‑coding credentials or modifying the Function App’s own authentication logic.

Typical use cases include continuous integration pipelines that need to validate new function deployments, interactive debugging sessions where an assistant can probe API behavior on the fly, and automated regression tests that verify endpoint contracts. By integrating with AI workflows, the tester allows assistants to suggest API calls, analyze responses, and even generate documentation or test cases on demand. This tight coupling between code and conversational tooling streamlines both development and quality assurance processes.

Overall, the MCP Function App Tester offers a concise, well‑documented interface for probing Azure Functions from within AI assistants. Its support for multiple HTTP verbs, comprehensive response reporting, and flexible authentication make it a practical addition to any developer’s toolkit when building or refining serverless APIs.