Free API List

A community-maintained catalog of free public APIs, with an in-browser test harness and an MCP server that exposes the catalog to Claude (or any MCP-aware coding agent).

What's in the box

free-api-list/
├── packages/catalog/      # The Zod-validated API catalog. The source of truth.
├── packages/web/          # The website (Vite + React 19 + MUI 7).
└── packages/mcp-server/   # MCP server (npx @free-api-list/mcp-server).

The catalog is upstream of everything. Adding an API means editing one JSON file in packages/catalog/apis/ — no TypeScript, no build system knowledge required.

Contribute

Two clear tracks:

• Want to add an API to the list? Read Track A of CONTRIBUTING.md. One JSON file, one PR.
• Want to work on the code or the MCP server? Read Track B of CONTRIBUTING.md and AGENTS.md.

Run the web app locally

pnpm install
pnpm dev
# open http://localhost:5173

Use the MCP server with Claude

Add to your MCP client config (Claude Code, Claude Desktop, Cursor, …):

{
  "mcpServers": {
    "free-api-list": {
      "command": "npx",
      "args": ["-y", "@free-api-list/mcp-server"]
    }
  }
}

Then ask things like "What free weather APIs are in the catalog?" or "Suggest 3 APIs I could use for a generative-art project."

Tools exposed: list_apis, search_apis, get_api, suggest_apis_for_task. See packages/mcp-server/README.md.

Tech stack

Layer	Choice
Package manager	pnpm + workspaces
Language	TypeScript strict
Web bundler	Vite 6
UI framework	React 19 + MUI 7
Schema	Zod
MCP SDK	@modelcontextprotocol/sdk
Testing	Vitest
Lint/format	Biome
Hosting	Cloudflare Pages (web) + Workers (CORS proxy + MCP HTTP)

License

MIT — see LICENSE.