ClawPurse
402 Gateway

Two micropayment flows: pay-per-request and prepaid balance

Whether your agent pays per call or pre-funds a balance, the gateway handles invoice creation, on-chain verification, and upstream proxying automatically.

Built for AI agents and machine-to-machine commerce

Everything a machine-to-machine micropayment layer needs, nothing it doesn’t.

Gateway API endpoint reference

Free endpoints for health checks, invoice lookups, and balance queries. Everything else goes through the 402 gate.

Agent integration: Python and TypeScript examples

Wire the 402 flow into any agent in a few lines. The gateway handles invoicing and verification — your code just needs to pay and retry.

import requests, subprocess, os

res = requests.get("http://gateway:4020/api/data")

if res.status_code == 402:
    inv = res.json()["payment"]

    # Pay with ClawPurse
    subprocess.run([
        "clawpurse", "send",
        inv["address"], inv["amount"],
        "--memo", inv["memo"], "--yes"
    ])

    # Retry with proof
    res = requests.get(
        "http://gateway:4020/api/data",
        headers={"X-Payment-Proof": inv["invoiceId"]}
    )

data = res.json()

async function paidFetch(url: string) {
  let res = await fetch(url);

  if (res.status === 402) {
    const { payment } = await res.json();

    // Pay with ClawPurse
    const { send, loadKeystore }
      = await import("clawpurse");
    const { wallet, address }
      = await loadKeystore(
          process.env.CLAWPURSE_PASSWORD!
        );
    await send(
      wallet, address,
      payment.address, payment.amount,
      { memo: payment.memo }
    );

    // Retry with proof
    res = await fetch(url, {
      headers: {
        "X-Payment-Proof": payment.invoiceId
      }
    });
  }
  return res.json();
}

Install and run the gateway in under a minute

# Clone and install
git clone https://github.com/mhue-ai/clawpurse-gateway.git
cd clawpurse-gateway && npm install

# Configure
cp .env.example .env
# Set GATEWAY_PAYMENT_ADDRESS and JWT_SECRET

# Start a test upstream
npm run test:upstream

# Start the gateway
npm run dev

# Test the 402 flow
curl http://localhost:4020/api/test
# Pay, then retry with proof:
curl -H "X-Payment-Proof: <invoiceId>" \
     http://localhost:4020/api/test

TypeScript microservice architecture

A focused TypeScript codebase — gateway logic, four internal services, and middleware. 46 unit tests cover every layer.

Gateway configuration via environment variables

All settings via env vars or .env file.

Part of the Timpi, Neutaro & ClawPurse ecosystem

Frequently asked questions