MCP API Translator MCP server

mcp-api-translator

An MCP server that generates MCP servers. Give it an API definition — OpenAPI 3.0/3.1 or a Postman collection — and it scaffolds a complete, runnable, ownable TypeScript or Python MCP server for that API.

Above: curating Firecrawl's 20 operations down to 6, appending the Gmail API to the same server, then an agent calling the self-hosted result. Counts, tool names and paths come from real runs against the published Firecrawl and Gmail descriptions; the API responses are illustrative — the recording runs against a local stub, not live Firecrawl or Gmail accounts.

Why this and not a 1:1 generator

Turning an OpenAPI spec into MCP "tool stubs" is not novel — FastMCP's from_openapi, Speakeasy/Gram, and several openapi-mcp-generator projects already do the mechanical part. A naive endpoint→tool generator has no real advantage. This project focuses on the parts those tools skip:

1. Curation, not just generation. A 200-endpoint API naively becomes 200 tools, which wrecks a model's tool-selection accuracy and blows out context. analyze_spec previews the tool list before anything is written, every command takes includeTags / methods / pathGlob / excludeOperations, and you get a warning when a server grows past 40 tools.

2. Aggregation via append. extendmcpserver adds another API's tools to an existing project, so you can build one MCP server spanning Firecrawl + Gmail + your internal API. Credentials stay separate: each API also reads namespaced env vars derived from its title.

3. An artifact you own. Output is a normal project, not a hosted black box — readable per-tool files, env-based auth, a Dockerfile, and a server.json plus client snippets for publishing to the official MCP Registry.

If you only need throwaway, in-memory exposure of one API and don't care about owning the code, FastMCP's runtime mode may suit you better — that's a deliberate non-goal here.

Install

No install step. npx fetches and runs the latest published version — cross-platform, Node 20+.

Claude Code

Claude Code does not read claudedesktopconfig.json — it keeps its own MCP config:

claude mcp add api-translator -- npx -y mcp-api-translator

That registers it at local scope. Use -s user for all your projects, or commit a project-scoped .mcp.json to share it. Verify with claude mcp list.

Claude Desktop

Add to claudedesktopconfig.json (macOS: ~/Library/Application Support/Claude/claudedesktopconfig.json, Windows: %APPDATA%\Claude\claudedesktopconfig.json):

{
  "mcpServers": {
    "api-translator": {
      "command": "npx",
      "args": ["-y", "mcp-api-translator"]
    }
  }
}

Cursor, Cline, Continue.dev, Docker

Cursor — ~/.cursor/mcp.json (or project-scoped .cursor/mcp.json), same mcpServers shape as Claude Desktop above.

Cline (VS Code) — sidebar → MCP Servers → Configure, same shape plus "disabled": false.

Shortened. The full README is on GitHub.