FastMCP

aid: fastmcp
name: FastMCP
description: >-
  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.
kind: contract
position: Producing
access: 3rd-Party
image: https://kinlane-productions2.s3.amazonaws.com/apis-json/apis-json-logo.jpg
tags:
- MCP
- Model Context Protocol
- Python
- Framework
- Open Source
- AI Agents
- Tools
- Resources
- Prompts
- LLMs
- Anthropic
created: '2026-05-25'
modified: '2026-05-25'
url: https://raw.githubusercontent.com/api-evangelist/fastmcp/refs/heads/main/apis.yml
specificationVersion: '0.19'
apis:
- aid: fastmcp:fastmcp-server
  name: FastMCP Server
  description: >-
    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 object and register
    components with decorators (`@mcp.tool`, `@mcp.resource`, `@mcp.prompt`). Schemas are generated
    automatically from Python type hints, with built-in support for dependency injection, middleware,
    lifespan management, context, structured logging, progress reporting, elicitation, authorization,
    component visibility, pagination, namespace transforms, and OpenTelemetry. Servers can be composed
    via mounting and proxying, and exposed over stdio, Streamable HTTP, or SSE transports.
  humanURL: https://gofastmcp.com/servers/server
  baseURL: ''
  tags:
  - MCP
  - Server
  - Tools
  - Resources
  - Prompts
  - Python
  - Framework
  properties:
  - type: Documentation
    url: https://gofastmcp.com/servers/server
  - type: Documentation
    name: Tools
    url: https://gofastmcp.com/servers/tools
  - type: Documentation
    name: Resources and Templates
    url: https://gofastmcp.com/servers/resources
  - type: Documentation
    name: Prompts
    url: https://gofastmcp.com/servers/prompts
  - type: Documentation
    name: Middleware
    url: https://gofastmcp.com/servers/middleware
  - type: Documentation
    name: Dependency Injection
    url: https://gofastmcp.com/servers/dependency-injection
  - type: Documentation
    name: Lifespan Management
    url: https://gofastmcp.com/servers/lifespan
  - type: Documentation
    name: Context
    url: https://gofastmcp.com/servers/context
  - type: Documentation
    name: Elicitation
    url: https://gofastmcp.com/servers/elicitation
  - type: Documentation
    name: Progress Reporting
    url: https://gofastmcp.com/servers/progress
  - type: Documentation
    name: Composition
    url: https://gofastmcp.com/servers/composition
  - type: Documentation
    name: Testing
    url: https://gofastmcp.com/servers/testing
  - type: Documentation
    name: OpenTelemetry
    url: https://gofastmcp.com/servers/telemetry
- aid: fastmcp:fastmcp-client
  name: FastMCP Client
  description: >-
    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, getting prompts,
    declaring roots, monitoring progress, server logging, notifications, user elicitation, LLM
    sampling, and background tasks across stdio, Streamable HTTP, and SSE transports. Authentication
    is built in via Bearer tokens, OAuth, and CIMD. A standalone `fastmcp-client` package is
    available when only the client is needed.
  humanURL: https://gofastmcp.com/clients/client
  baseURL: ''
  tags:
  - MCP
  - Client
  - Python
  - Library
  properties:
  - type: Documentation
    url: https://gofastmcp.com/clients/client
  - type: Documentation
    name: Calling Tools
    url: https://gofastmcp.com/clients/tools
  - type: Documentation
    name: Reading Resources
    url: https://gofastmcp.com/clients/resources
  - type: Documentation
    name: Getting Prompts
    url: https://gofastmcp.com/clients/prompts
  - type: Documentation
    name: Client Transports
    url: https://gofastmcp.com/clients/transports
  - type: Documentation
    name: Bearer Token Authentication
    url: https://gofastmcp.com/clients/auth/bearer
  - type: Documentation
    name: OAuth Authentication
    url: https://gofastmcp.com/clients/auth/oauth
  - type: Documentation
    name: CIMD Authentication
    url: https://gofastmcp.com/clients/auth/cimd
  - type: Documentation
    name: LLM Sampling
    url: https://gofastmcp.com/clients/sampling
  - type: Documentation
    name: User Elicitation
    url: https://gofastmcp.com/clients/elicitation
  - type: Documentation
    name: Client-Only Package
    url: https://gofastmcp.com/clients/client-only-package
- aid: fastmcp:fastmcp-apps
  name: FastMCP Apps
  description: >-
    FastMCP Apps is the framework's runtime for building interactive applications rendered directly
    inside MCP host conversations. Apps expose UI surfaces — approval flows, choice pickers, form
    input, and file uploads — alongside prefab and low-level HTML/generative UIs, with `FastMCPApp`
    as the primary entry point. Apps share the same transport and authentication stack as FastMCP
    servers, enabling rich agent experiences across Claude Desktop, Claude Code, Cursor, and other
    MCP-aware hosts.
  humanURL: https://gofastmcp.com/apps/overview
  baseURL: ''
  tags:
  - MCP
  - Apps
  - UI
  - Interactive
  - Python
  properties:
  - type: Documentation
    url: https://gofastmcp.com/apps/overview
  - type: Documentation
    name: App Quickstart
    url: https://gofastmcp.com/apps/quickstart
  - type: Documentation
    name: FastMCPApp
    url: https://gofastmcp.com/apps/fastmcp-app
  - type: Documentation
    name: Architecture
    url: https://gofastmcp.com/apps/architecture
  - type: Documentation
    name: Interactive Tools (Prefab)
    url: https://gofastmcp.com/apps/prefab
  - type: Documentation
    name: Generative UI
    url: https://gofastmcp.com/apps/generative
  - type: Documentation
    name: Custom HTML Apps
    url: https://gofastmcp.com/apps/low-level
  - type: Documentation
    name: Approval Provider
    url: https://gofastmcp.com/apps/providers/approval
  - type: Documentation
    name: Choice Provider
    url: https://gofastmcp.com/apps/providers/choice
  - type: Documentation
    name: Form Input Provider
    url: https://gofastmcp.com/apps/providers/form
  - type: Documentation
    name: File Upload Provider
    url: https://gofastmcp.com/apps/providers/file-upload
- aid: fastmcp:fastmcp-auth
  name: FastMCP Authentication
  description: >-
    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 provider,
    and they can combine multiple authentication sources. Out-of-the-box providers cover Auth0,
    AWS Cognito, Azure/Entra ID, GitHub, Google, Discord, Keycloak, OCI IAM, Supabase, WorkOS,
    AuthKit, Descope, PropelAuth, and Scalekit. Authorization integrations include Permit.io and
    Eunomia.
  humanURL: https://gofastmcp.com/servers/auth/authentication
  baseURL: ''
  tags:
  - MCP
  - Authentication
  - OAuth
  - OIDC
  - Authorization
  - Security
  properties:
  - type: Documentation
    name: Authentication Overview
    url: https://gofastmcp.com/servers/auth/authentication
  - type: Documentation
    name: Token Verification
    url: https://gofastmcp.com/servers/auth/token-verification
  - type: Documentation
    name: OAuth Proxy
    url: https://gofastmcp.com/servers/auth/oauth-proxy
  - type: Documentation
    name: OIDC Proxy
    url: https://gofastmcp.com/servers/auth/oidc-proxy
  - type: Documentation
    name: Multiple Auth Sources
    url: https://gofastmcp.com/servers/auth/multi-auth
  - type: Documentation
    name: Remote OAuth
    url: https://gofastmcp.com/servers/auth/remote-oauth
  - type: Documentation
    name: Full OAuth Server
    url: https://gofastmcp.com/servers/auth/full-oauth-server
  - type: Documentation
    name: Authorization
    url: https://gofastmcp.com/servers/authorization
- aid: fastmcp:fastmcp-openapi
  name: FastMCP OpenAPI and FastAPI Integration
  description: >-
    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 schemas
    and validation. This makes FastMCP a one-step path from any existing REST API to an
    agent-callable MCP surface, and is the recommended route for retrofitting MCP onto established
    services without rewriting business logic.
  humanURL: https://gofastmcp.com/integrations/openapi
  baseURL: ''
  tags:
  - MCP
  - OpenAPI
  - FastAPI
  - REST
  - Integration
  properties:
  - type: Documentation
    name: OpenAPI Integration
    url: https://gofastmcp.com/integrations/openapi
  - type: Documentation
    name: FastAPI Integration
    url: https://gofastmcp.com/integrations/fastapi
- aid: fastmcp:fastmcp-cli
  name: FastMCP CLI
  description: >-
    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, inspect
    their tool/resource/prompt manifests, install servers into Claude Desktop, Claude Code, Cursor,
    ChatGPT, and Gemini CLI, generate boilerplate, and manage authentication artifacts.
  humanURL: https://gofastmcp.com/cli/overview
  baseURL: ''
  tags:
  - MCP
  - CLI
  - Developer Tools
  properties:
  - type: Documentation
    name: CLI Overview
    url: https://gofastmcp.com/cli/overview
  - type: Documentation
    name: Running Servers
    url: https://gofastmcp.com/cli/running
  - type: Documentation
    name: Client Commands
    url: https://gofastmcp.com/cli/client
  - type: Documentation
    name: Installing MCP Servers
    url: https://gofastmcp.com/cli/install-mcp
  - type: Documentation
    name: Inspecting Servers
    url: https://gofastmcp.com/cli/inspecting
  - type: Documentation
    name: Generate CLI
    url: https://gofastmcp.com/cli/generate-cli
  - type: Documentation
    name: Auth Utilities
    url: https://gofastmcp.com/cli/auth
common:
- type: Website
  url: https://gofastmcp.com
- type: Portal
  name: FastMCP Documentation
  url: https://gofastmcp.com
- type: GettingStarted
  name: Welcome to FastMCP
  url: https://gofastmcp.com/getting-started/welcome
- type: Quickstart
  url: https://gofastmcp.com/getting-started/quickstart
- type: Installation
  url: https://gofastmcp.com/getting-started/installation
- type: Documentation
  name: Upgrading from FastMCP 2
  url: https://gofastmcp.com/getting-started/upgrading/from-fastmcp-2
- type: Documentation
  name: Upgrading from the Low-Level SDK
  url: https://gofastmcp.com/getting-started/upgrading/from-low-level-sdk
- type: Documentation
  name: Upgrading from the MCP SDK
  url: https://gofastmcp.com/getting-started/upgrading/from-mcp-sdk
- type: ChangeLog
  url: https://gofastmcp.com/changelog
- type: ReleaseNotes
  name: FastMCP Updates
  url: https://gofastmcp.com/updates
- type: FAQ
  url: https://gofastmcp.com/more/faq
- type: GitHubRepository
  url: https://github.com/PrefectHQ/fastmcp
- type: GitHubOrganization
  url: https://github.com/PrefectHQ
- type: SDK
  name: FastMCP on PyPI
  url: https://pypi.org/project/fastmcp
- type: Forum
  name: FastMCP Discord
  url: https://discord.gg/uu8dJCgttd
- type: Documentation
  name: Deployment - Running Your Server
  url: https://gofastmcp.com/deployment/running-server
- type: Documentation
  name: HTTP Deployment
  url: https://gofastmcp.com/deployment/http
- type: Documentation
  name: Project Configuration
  url: https://gofastmcp.com/deployment/server-configuration
- type: Documentation
  name: Sandboxed Agents
  url: https://gofastmcp.com/deployment/sandboxed-agents
- type: Documentation
  name: Prefect Horizon
  url: https://gofastmcp.com/deployment/prefect-horizon
- type: Documentation
  name: Contributing
  url: https://gofastmcp.com/development/contributing
- type: Documentation
  name: Releases
  url: https://gofastmcp.com/development/releases
- type: Documentation
  name: Tests
  url: https://gofastmcp.com/development/tests
- type: License
  name: Apache License 2.0
  url: https://github.com/PrefectHQ/fastmcp/blob/main/LICENSE
- type: Features
  data:
  - name: Decorator-based tools, resources, and prompts
    description: Turn Python functions into MCP tools, resources, and prompts with @mcp.tool / @mcp.resource / @mcp.prompt; schemas are auto-generated from type hints.
  - name: FastMCP Server, Client, and Apps
    description: Three composable surfaces — Server (expose), Client (consume), Apps (interactive UI) — sharing a single runtime, transport, and auth stack.
  - name: Transport negotiation
    description: Built-in support for stdio, Streamable HTTP, and SSE transports with zero boilerplate.
  - name: First-class authentication
    description: Token verification, OAuth Proxy, OIDC Proxy, remote OAuth, full OAuth server, multi-auth sources, and 15+ provider integrations (Auth0, Cognito, Azure/Entra, GitHub, Google, Discord, Keycloak, OCI, Supabase, WorkOS, AuthKit, Descope, PropelAuth, Scalekit).
  - name: Authorization providers
    description: Permit.io and Eunomia integrations for policy-driven authorization.
  - name: OpenAPI and FastAPI import
    description: Generate an MCP server directly from an OpenAPI spec or FastAPI app so existing REST APIs become agent-callable in one step.
  - name: Server composition and proxying
    description: Mount servers under namespaces, proxy to other MCP servers (including local, filesystem, and skills providers), and transform tools/prompts/resources between surfaces.
  - name: Middleware and dependency injection
    description: Wrap requests with middleware and inject runtime dependencies into tool handlers.
  - name: Lifespan, context, logging, progress, elicitation
    description: Full MCP protocol coverage including lifespan management, request context, structured logging, progress reporting, and user elicitation.
  - name: LLM sampling and background tasks
    description: Client APIs for LLM sampling against the host model and for spawning background tasks.
  - name: OpenTelemetry instrumentation
    description: Built-in OpenTelemetry tracing for servers.
  - name: Tool transforms
    description: Tool Transformation, Tool Search, Prompts-as-Tools, Resources-as-Tools, Namespace, Component Visibility, and Code Mode transforms.
  - name: Pagination, versioning, storage backends, icons
    description: Production-grade primitives for paginated responses, server versioning, pluggable storage backends, and component icons.
  - name: CLI for running and installing servers
    description: Run, inspect, install, and generate FastMCP servers and clients; one-line install into Claude Desktop, Claude Code, Cursor, ChatGPT, and Gemini CLI.
  - name: Apps runtime
    description: Approval, Choice, Form Input, and File Upload providers plus prefab, generative, and low-level HTML apps rendered inside MCP host conversations.
  - name: Anthropic-adopted lineage
    description: FastMCP 1.0 was incorporated into the official Anthropic MCP Python SDK; the standalone FastMCP project (now v3) continues as the leading Python framework, reportedly powering ~70% of MCP servers across all languages.
  sources:
  - https://gofastmcp.com
  - https://gofastmcp.com/llms.txt
  - https://github.com/PrefectHQ/fastmcp
  updated: '2026-05-25'
- type: UseCases
  data:
  - name: Wrap an existing REST API as an MCP server
    description: Point FastMCP at an OpenAPI spec or FastAPI app to expose every operation as an MCP tool without rewriting handlers.
  - name: Build agent-callable internal tools
    description: Expose internal utilities (databases, search, ticketing, CI/CD, infra) to Claude, ChatGPT, Cursor, or any MCP host as governed tools.
  - name: Ship interactive MCP apps
    description: Use FastMCP Apps to render approval prompts, choice pickers, forms, and file uploads inside agent conversations.
  - name: Proxy and compose third-party MCP servers
    description: Aggregate multiple MCP servers behind a single namespaced surface with the proxy and namespace transforms.
  - name: Add OAuth/OIDC to an MCP deployment
    description: Drop in one of 15+ identity providers to authenticate real users into an MCP server without writing OAuth plumbing.
  - name: Production deployment of MCP servers
    description: Deploy MCP servers over HTTP with structured config, sandboxed agents, OpenTelemetry, and optional Prefect Horizon for managed runtime.
  - name: Local agent tooling
    description: Install FastMCP servers into Claude Desktop, Claude Code, Cursor, ChatGPT, or Gemini CLI via the FastMCP CLI for stdio-based local agent workflows.
- type: Integrations
  data:
  - name: Anthropic API
    description: First-party integration with the Anthropic Messages API; FastMCP 1.0 was adopted into the official Anthropic MCP Python SDK.
  - name: Model Context Protocol
    description: Reference implementation of the Anthropic-stewarded Model Context Protocol specification.
  - name: OpenAI API
    description: Connect FastMCP servers to OpenAI models and the OpenAI API.
  - name: Google Gemini
    description: Integration with Google Gemini SDK and Gemini CLI.
  - name: Pydantic AI
    description: Drop FastMCP servers into Pydantic AI agents.
  - name: Claude Desktop
    description: One-line install for FastMCP servers into Claude Desktop.
  - name: Claude Code
    description: Install FastMCP servers into Claude Code as MCP tools.
  - name: Cursor
    description: Install FastMCP servers into the Cursor editor.
  - name: ChatGPT
    description: Install FastMCP servers into ChatGPT.
  - name: Goose
    description: Integration with Block's Goose agent runtime.
  - name: OpenAPI
    description: Import any OpenAPI 3.x spec and serve it as an MCP server.
  - name: FastAPI
    description: Wrap a FastAPI app as an MCP server with one line.
  - name: Auth0, AWS Cognito, Azure/Entra ID, GitHub, Google, Discord, Keycloak, OCI IAM, Supabase, WorkOS, AuthKit, Descope, PropelAuth, Scalekit
    description: First-class OAuth provider integrations for authenticating MCP servers.
  - name: Permit.io and Eunomia
    description: Policy-driven authorization integrations.
  - name: Prefect Horizon
    description: Managed deployment platform for MCP servers from the FastMCP maintainers at PrefectHQ.
  sources:
  - https://gofastmcp.com/llms.txt
  updated: '2026-05-25'
maintainers:
- FN: Kin Lane
  email: [email protected]