api-mcp

A Model Context Protocol server that lets an LLM make arbitrary HTTP API requests using any method — GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS — against any URL.

It exposes one general-purpose tool plus thin per-method convenience wrappers, so a model can call whatever REST/HTTP API it needs with full control over headers, query parameters, and request bodies.

Tools

Arguments

All tools accept the same arguments (the per-method tools omit method):

Response

Each call returns a JSON object with:

{
  "request": { "method": "POST", "url": "https://api.example.com/items?x=1" },
  "status": 201,
  "statusText": "Created",
  "ok": true,
  "elapsed_ms": 142,
  "headers": { "content-type": "application/json", ... },
  "body_bytes": 87,
  "body_truncated": false,
  "body_encoding": "utf-8",
  "body": "{\"id\":\"abc\"}"
}

A non-2xx status is returned as a normal (non-error) result — it's real information about the API, not a tool failure. Only network errors, timeouts, and invalid URLs are reported as tool errors.

Binary & non-text responses

The body is returned as either UTF-8 text or base64, and body_encoding tells you which. With the default response_encoding: "auto":

• Textual content types (text/*, and application/* subtypes containing json, xml, javascript, csv, yaml, svg, etc.) are decoded as UTF-8.

• Everything else (images, PDFs, archives, application/octet-stream, …) is returned as base64.

• When the response has no Content-Type, the bytes are sniffed for NUL bytes to guess text vs. binary.

Override the heuristic with response_encoding:

• "text" — always decode as UTF-8.

• "base64" — always base64-encode (useful when a server mislabels a binary payload as text).

Related MCP server: API Request MCP Server

Install & build

npm install    # also builds via the prepare script
npm run build  # or build explicitly

Run

The server speaks MCP over stdio:

node dist/index.js

Configure in an MCP client

Claude Code

claude mcp add api-mcp -- node /absolute/path/to/api-mcp/dist/index.js

Claude Desktop / generic client

Add to your MCP config (e.g. claude_desktop_config.json):

{
  "mcpServers": {
    "api-mcp": {
      "command": "node",
      "args": ["/absolute/path/to/api-mcp/dist/index.js"]
    }
  }
}

Example calls

Fetch JSON:

// tool: get
{ "url": "https://api.github.com/repos/anthropics/anthropic-sdk-python" }

Create a resource with a JSON body and auth header:

// tool: post
{
  "url": "https://api.example.com/v1/items",
  "headers": { "Authorization": "Bearer sk-…" },
  "json": { "name": "widget", "qty": 3 }
}

Send a raw form-encoded body:

// tool: http_request
{
  "method": "PUT",
  "url": "https://api.example.com/v1/items/42",
  "headers": { "Content-Type": "application/x-www-form-urlencoded" },
  "body": "name=widget&qty=5"
}

Security note

This server can reach any URL the host machine can reach, including internal network addresses, using whatever credentials the model supplies in headers. Run it only in trusted contexts and be mindful of what URLs and secrets you allow a model to send.

License

MIT