@andesmountain/stdio-bridge-http

x402 stdio bridge for Claude Desktop and Chatbox: connect MCP stdio to an HTTP API with 402 payment. The bridge speaks MCP over stdio and calls your HTTP backend; payment is handled in the bridge so the model never sees x402 details.

Quick start (npx)

No clone required. In your Claude Desktop or Chatbox MCP config, use:

{
  "mcpServers": {
    "demo-http": {
      "command": "npx",
      "args": ["-y", "@andesmountain/stdio-bridge-http"],
      "env": {
        "EVM_PRIVATE_KEY": "0x...",
        "HTTP_SERVER_URL": "http://localhost:4021",
        "FACILITATOR_URL": "https://x402.org/facilitator"
      }
    }
  }
}

• EVM_PRIVATE_KEY (required): EVM wallet private key (with 0x prefix). Must have testnet funds for payment.
• HTTP_SERVER_URL (optional): Your x402 HTTP server base URL. Default: http://localhost:4021.
• FACILITATOR_URL (optional): x402 facilitator URL.

Ensure your HTTP server is running (e.g. the Express example). The bridge exposes a single tool get_weather that calls GET {HTTP_SERVER_URL}/weather?city=... and handles 402 payment.

Install as dependency

pnpm add @andesmountain/stdio-bridge-http
# or
npm i @andesmountain/stdio-bridge-http

Then in MCP config:

{
  "mcpServers": {
    "demo-http": {
      "command": "pnpm",
      "args": ["exec", "stdio-bridge-http"],
      "env": {
        "EVM_PRIVATE_KEY": "0x...",
        "HTTP_SERVER_URL": "http://localhost:4021",
        "FACILITATOR_URL": "https://x402.org/facilitator"
      }
    }
  }
}

Or with Node directly (after node_modules/.bin in PATH or full path):

"command": "node",
"args": ["node_modules/@andesmountain/stdio-bridge-http/dist/cli.js"],
"env": { ... }

Flow

Claude Desktop / Chatbox (stdio MCP)
        ↓
  this bridge (x402 client)
        ↓
  Your HTTP API (e.g. Express + x402 middleware)

Tools are defined in the bridge; when a tool is called, the bridge performs the HTTP request and handles 402 payment, then returns the result over MCP.

License

Apache-2.0