Skip to content

FastMCP

FastMCP is a Python framework for describing functions and resources that an MCP client can use.

Visit FastMCP

What do you write and what does the framework handle?

Write a Python function with a clear job and describe the input it needs. FastMCP can expose it as an MCP tool. Pick the package and version that match the documentation you are following. The standalone project has its own release and documentation.

How do you keep a first test small?

Keep the function local, pass invented inputs and give it only the data needed for the result. The framework can expose what your code does. Review each tool before allowing a client to use it. Keep the Python source and dependency choices so the test is reproducible.

What would a fictional reference tool accept?

Draw a local tool that returns the opening hours for one invented location.

  1. Pick a small input
    Use a sample location name and mark the exact response you expect.
  2. Handle an unknown name
    Write a plain message for a name the example does not recognize.