# FastMCP

**Canonical:** https://apis.io/providers/fastmcp/  
**Website:** https://gofastmcp.com  
**APIs profiled:** 6

FastMCP is the fast, Pythonic framework for building Model Context Protocol (MCP) servers, clients, and apps. Originally created by Jeremiah Lowin and maintained by PrefectHQ, FastMCP 1.0 was adopted into the official Anthropic MCP Python SDK in 2024, and the standalone FastMCP project (now at v3) remains the most widely used way to ship MCP servers in Python — the project reports powering roughly 70% of MCP servers across all languages. FastMCP turns ordinary Python functions into MCP tools, resources, prompts, and apps via decorators, auto-generates JSON Schemas from type hints, handles transport negotiation (stdio, Streamable HTTP, SSE), and ships first-class OAuth/OIDC authentication, server composition and proxying, OpenAPI/FastAPI import, a CLI for running and installing servers into Claude Desktop / Claude Code / Cursor / ChatGPT / Gemini CLI / Goose, middleware, lifespan management, elicitation, sampling, progress reporting, OpenTelemetry, and a client library and apps runtime for building interactive UIs rendered inside MCP host conversations.

## Kin Score — 19.7 / 100 (emerging)

Scored 2026-08-25 under rubric 0.14.0. Trend: flat (+0.0 from 19.7).

| Facet | Score |
|---|---|
| Discoverability | 74.1 |
| Contract Quality | 0.0 |
| Governance | 0.0 |
| Contract Governance | 0.0 |
| Operational Transparency | 28.9 |
| Developer Ergonomics | 42.9 |
| Commercial Clarity | 0.0 |
| Access Clarity | 0.0 |

## Agent readiness — 3.5 (human-only)

| Dimension | Value |
|---|---|
| Spec Presence | no |
| Agentic Access | no |
| Reversibility Documented | no |
| MCP Server | no |
| Auth Clarity | no |
| Idempotency | no |
| Error Semantics | no |
| OpenAPI Examples | no |
| Rate Limit Signal | no |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | near-conformant |
| Dry Run Mode | no |
| Delegated Identity | no |
| Protected Resource Metadata | no |
| Dynamic Client Registration | no |
| Agentic Commerce | no |

## APIs (6)

- **FastMCP Server** — The FastMCP Server is the Python entry point for exposing tools, resources, prompts, and apps to any Model Context Protocol client. Developers instantiate a `FastMCP` server obj...
- **FastMCP Client** — The FastMCP Client is a Python client library for talking to any MCP server — local or remote — with full protocol coverage. It supports calling tools, reading resources, gettin...
- **FastMCP Apps** — FastMCP Apps is the framework's runtime for building interactive applications rendered directly inside MCP host conversations. Apps expose UI surfaces — approval flows, choice p...
- **FastMCP Authentication** — FastMCP ships a complete authentication and authorization layer for MCP servers. Servers can verify tokens, terminate OAuth flows directly, or proxy to an external OAuth or OIDC...
- **FastMCP OpenAPI and FastAPI Integration** — FastMCP can generate an MCP server directly from an existing OpenAPI 3.x description or a FastAPI application, turning every HTTP operation into an MCP tool with auto-generated ...
- **FastMCP CLI** — The FastMCP CLI is a developer command-line tool for running, inspecting, installing, and debugging MCP servers built with FastMCP. It can launch servers under any transport, in...

## Security (1)

- **Fastmcp Domain Security** — TLSv1.3 · HSTS · DMARC

## Use cases (7)

- **Wrap an existing REST API as an MCP server** — Point FastMCP at an OpenAPI spec or FastAPI app to expose every operation as an MCP tool without rewriting handlers.
- **Build agent-callable internal tools** — Expose internal utilities (databases, search, ticketing, CI/CD, infra) to Claude, ChatGPT, Cursor, or any MCP host as governed tools.
- **Ship interactive MCP apps** — Use FastMCP Apps to render approval prompts, choice pickers, forms, and file uploads inside agent conversations.
- **Proxy and compose third-party MCP servers** — Aggregate multiple MCP servers behind a single namespaced surface with the proxy and namespace transforms.
- **Add OAuth/OIDC to an MCP deployment** — Drop in one of 15+ identity providers to authenticate real users into an MCP server without writing OAuth plumbing.
- **Production deployment of MCP servers** — Deploy MCP servers over HTTP with structured config, sandboxed agents, OpenTelemetry, and optional Prefect Horizon for managed runtime.
- **Local agent tooling** — Install FastMCP servers into Claude Desktop, Claude Code, Cursor, ChatGPT, or Gemini CLI via the FastMCP CLI for stdio-based local agent workflows.

## Tags

MCP, Python, Framework, Open-Source, AI Agents, Tools, Resources, Prompts, LLMs, Anthropic

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/fastmcp/). Scores are computed from the provider's own public artifacts under a published rubric.