import requests, base64, json, time

resp = requests.get('https://defi-rates.qingfenghello.workers.dev/v1/rates/borrow')
if resp.status_code == 402:
    payment = resp.json()["payment"]
    proof_payload = {
        "chain": "base",
        "txHash": "0xabc...",
        "payer": "0xYour...",
        "amount": "0.0005",
        "token": "USDC",
        "nonce": payment["nonce"],
        "expires_at": payment["expires_at"],
        "path": "/v1/rates/borrow",
        "signature": "0xEIP712Signature..."
    }
    proof = base64.b64encode(json.dumps(proof_payload).encode()).decode()
    resp = requests.get('https://defi-rates.qingfenghello.workers.dev/v1/rates/borrow', headers={'X-Payment': proof})

let resp = await axios.get('https://defi-rates.qingfenghello.workers.dev/v1/rates/borrow').catch(err => err.response);
if (resp.status === 402) {
  const payment = resp.data.payment;
  const proof = Buffer.from(JSON.stringify({
    chain: "base",
    txHash: "0x...",
    payer: "0x...",
    amount: "0.0005",
    token: "USDC",
    nonce: payment.nonce,
    expires_at: payment.expires_at,
    path: "/v1/rates/borrow",
    signature: "0xEIP712Signature..."
  })).toString('base64');
  resp = await axios.get('https://defi-rates.qingfenghello.workers.dev/v1/rates/borrow', { headers: { 'X-Payment': proof } });
}