Fast MCP Server (Frank Fiegel)
Build TypeScript MCP servers with built-in session tracking and OpenAPI support.
Data last scanned today · Reviewed today
Overview
FastMCP serves as a TypeScript-based abstraction layer built atop the official SDK, designed to streamline server construction through simplified resource, tool, and prompt definitions. It offers advanced developer features including HTTP streaming, custom route handling, and edge runtime compatibility for deployments like Cloudflare Workers. The framework provides native support for session and request ID tracking, image and audio content handling, and prompt argument auto-completion. It also includes an in-memory transport mechanism for unit testing and an integrated CLI for debugging and inspection, addressing implementation complexities often left to the developer by the base SDK.
Our verdict
This server carries a high risk level with a security score of 53/100, primarily because the authentication methods and read-only modes have not yet been editorially reviewed. While it maintains a large community presence with 3,263 GitHub stars and 84 contributors, users should exercise caution as it is a community-maintained project rather than an official vendor release. Developers must also be aware that it implements a legacy handshake-based MCP revision (2025-11-25) and is not compatible with the current stateless specification.
- Supports edge runtimes like Cloudflare Workers and Deno Deploy
- Simplifies development with built-in OpenAPI to MCP conversion
- Provides an in-memory transport for testing without network binding
- Maintains a small supply-chain footprint with 14 direct dependencies
- Does not support the current stateless MCP specification
- Authentication and read-only modes lack formal security review
- Community-maintained status lacks official vendor oversight
Setup
{
"mcpServers": {
"punkpeye-fastmcp": {
"args": [
"-y",
"fastmcp"
],
"command": "npx"
}
}
}Paste into ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows), then restart Claude Desktop. Some servers require API keys or tokens as environment variables — check the project's README and add an "env" object if needed.
- No read-only mode — running this grants full read/write access.
- No built-in authentication — anyone with access to this config can invoke every tool it exposes.
Tools
| Tool | Description | Risk |
|---|---|---|
| fetch-zod | Fetch the content of a url (using Zod) | low |
| fetch-arktype | Fetch the content of a url (using ArkType) | low |
| fetch-valibot | Fetch the content of a url (using Valibot) | low |
| fetch-json-schema | Fetch the content of a url (using plain JSON Schema) | low |
| sayHello | Say hello | low |
| get-weather | Get weather for a city | low |
| admin-tool | An admin-only tool | medium |
| download | Download a file | low |
| fetch_report | — | low |
| generateText | Generate text incrementally | low |
Compatibility
| Client | Local | Docker | Remote | Read-only |
|---|---|---|---|---|
| ChatGPT | ||||
| Claude Desktop | ||||
| Cursor | ||||
| VS Code | ||||
| Windsurf |
Frequently asked questions
›Which version of the Model Context Protocol does FastMCP support?
FastMCP implements legacy, handshake-based MCP revisions dated 2025-11-25 and earlier. It does not support the current stateless specification released on 2026-07-28.
›Does FastMCP support deployment on edge runtimes?
Yes, FastMCP includes edge runtime support for platforms such as Cloudflare Workers and Deno Deploy.
›Can I test my server without opening a network port?
Yes, you can use the built-in in-memory transport to perform unit testing without binding to a physical port.
›What transport options are available for remote communication?
FastMCP supports multiple transport options, including standard stdio and network-based communication via HTTP streaming or SSE compatibility.
›How does FastMCP differ from the official MCP SDK?
FastMCP is a wrapper built on top of the official SDK that provides an opinionated framework to handle boilerplate tasks like connection management, tool registration, and error handling automatically.
Changelog
Badge
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