FastMCP Updates

FastMCP 2.7 has been released!

Most notably, it introduces the highly requested (and Pythonic) “naked” decorator usage:

mcp = FastMCP()

@mcp.tool
def add(a: int, b: int) -> int:
    return a + b

In addition, decorators now return the objects they create, instead of the decorated function. This is an important usability enhancement.

The bulk of the update is focused on improving the FastMCP internals, including a few breaking internal changes to private APIs. A number of functions that have clung on since 1.0 are now deprecated.

FastMCP 2.6 is here!

This release introduces first-class authentication for MCP servers and clients, including pragmatic Bearer token support and seamless OAuth 2.1 integration. This release aligns with how major AI platforms are adopting MCP today, making it easier than ever to securely connect your tools to real-world AI models. Dive into the update and secure your stack with minimal friction.

Your tests are bad and you should feel bad.

Stop vibe-testing your MCP server through LLM guesswork. FastMCP 2.0 introduces in-memory testing for fast, deterministic, and fully Pythonic validation of your MCP logic—no network, no subprocesses, no vibes.

In just six weeks since its relaunch, FastMCP has surpassed 10,000 GitHub stars—becoming the fastest-growing OSS project in our orbit. What started as a personal itch has become the backbone of Python-based MCP servers, powering a rapidly expanding ecosystem. While the protocol itself evolves, FastMCP continues to lead with clarity, developer experience, and opinionated tooling. Here’s to what’s next.

FastMCP 2.3 introduces full support for Streamable HTTP, a modern alternative to SSE that simplifies MCP deployments over the web. It’s efficient, reliable, and now the default HTTP transport. Just run your server with transport=“streamable-http” and connect clients via a standard URL—FastMCP handles the rest. No special setup required. This release makes deploying MCP servers easier and more portable than ever.

Even AI needs a good travel adapter 🔌

FastMCP now supports proxying arbitrary MCP servers, letting you run a local FastMCP instance that transparently forwards requests to any remote or third-party server—regardless of transport. This enables transport bridging (e.g., stdio ⇄ SSE), simplified client configuration, and powerful gateway patterns. Proxies are fully composable with other FastMCP servers, letting you mount or import them just like local servers. Use FastMCP.from_client() to wrap any backend in a clean, Pythonic proxy.

This major release reimagines FastMCP as a full ecosystem platform, with powerful new features for composition, integration, and client interaction. You can now compose local and remote servers, proxy arbitrary MCP servers (with transport translation), and generate MCP servers from OpenAPI or FastAPI apps. A new client infrastructure supports advanced workflows like LLM sampling.

FastMCP 2.0 builds on the success of v1 with a cleaner, more flexible foundation—try it out today!

FastMCP 1.0 will become part of the official MCP Python SDK!

Because life’s too short for boilerplate.

This is where it all started. FastMCP’s launch post introduced a clean, Pythonic way to build MCP servers without the protocol overhead. Just write functions; FastMCP handles the rest. What began as a weekend project quickly became the foundation of a growing ecosystem.