FastAPI MCP Client

What is FastAPI MCP Client?

A specialized async client library for interacting with fastapi-mcp servers that implement the Model Context Protocol (MCP) over Server-Sent Events (SSE). It runs in any Python environment and is built for developers integrating with MCP-enabled FastAPI services.

How to use FastAPI MCP Client?

Install via pip install fastapi-mcp-client or uv add fastapi-mcp-client. Connect to an MCP server by creating an MCPClient instance with the server’s base URL, then call operations (e.g., client.call_operation("echo", {"message": "Hello"})). For streaming, pass stream=True and iterate over events. Session management and message passing are handled automatically.

Key features of FastAPI MCP Client

• Full MCP protocol implementation for FastAPI-based servers
• First-class SSE streaming support
• Fully async‑first design for high performance
• Seamless session establishment and message handling
• Comprehensive error handling with fallback mechanisms
• Complete type annotations for better IDE integration

Use cases of FastAPI MCP Client

• Call non‑streaming endpoints (e.g., echo, calculate) on MCP servers
• Consume real‑time streaming data (e.g., generated numbers, search results)
• Build conversational AI tools that communicate with MCP‑enabled APIs
• Replace manual HTTP handling with a high‑level, async MCP client

FAQ from FastAPI MCP Client

What is FastAPI MCP Client used for?

It is a Python client library designed specifically to call operations on MCP servers built with fastapi-mcp. It handles session initialization, message passing, and SSE streaming automatically.

How does it differ from generic MCP clients?

FastAPI MCP Client is tailored for servers using the fastapi-mcp extension and communicates over SSE rather than stdio or WebSocket. It offers a concise async interface and built‑in streaming support.

What Python versions or runtimes does it support?

The client is Python‑only and requires Python 3.8+ (as inferred from async/await syntax). It works with any environment that supports pip/uv.

Is FastAPI MCP Client free to use?

Yes. The project is licensed under the MIT License, so it is free for both personal and commercial use.

Are there any known limitations?

The README does not list specific limitations. The client is designed exclusively for fastapi-mcp servers and does not support other MCP transports like WebSocket or stdio.