Agent Payments (x402) - cred.diy API documentation

// Any credits-api call can now be paid for inline. When your CRD runs
// out the API answers 402 with a price instead of simply failing.
const call = () => fetch(
  'https://eutdgemlrpvnxfkkpvlu.supabase.co/functions/v1/credits-api/balance?user_id=user_123',
  { headers: { 'x-api-key': 'sk_live_your_api_key' } }
);

let response = await call();

if (response.status === 402) {
  const offer = JSON.parse(atob(response.headers.get('PAYMENT-REQUIRED')));
  // offer.accepts[0] -> { scheme, network, amount, asset, payTo, extra }
  const payload = await wallet.signX402(offer.accepts[0]);

  // Retry the *same* request with the signed payment attached.
  response = await fetch(response.url, {
    headers: {
      'x-api-key': 'sk_live_your_api_key',
      'PAYMENT-SIGNATURE': btoa(JSON.stringify(payload))
    }
  });
  // 200 OK — credits were topped up and the original request ran.
  // PAYMENT-RESPONSE header carries the on-chain settlement receipt.
}

// 1. Discover what Cred accepts — no credentials needed.
const res = await fetch(
  'https://eutdgemlrpvnxfkkpvlu.supabase.co/functions/v1/credits-api/x402/supported' +
  '?project_id=your_project_id'
);

const support = await res.json();
// {
//   x402Version: 2,
//   enabled: true,
//   kinds: [{ x402Version: 2, scheme: 'exact', network: 'eip155:84532' }],
//   asset: { address: '0x036CbD...', name: 'USDC', decimals: 6 },
//   facilitator: 'https://x402.org/facilitator',
//   platform_topup: { credits: 100, symbol: 'CRD', price_usd: 1, amount: '1000000' },
//   project: {
//     accepts_x402: true,
//     purchase_url: '.../credits-api/x402/purchase',
//     credit_type: { id: '...', name: 'Game Coins', symbol: 'GC' },
//     price_per_credit_usd: 0.01,
//     min_credits: 1,
//     max_credits: 10000
//   }
// }

// 2. Ask to buy. With no payment attached you get a 402 carrying the price.
const url =
  'https://eutdgemlrpvnxfkkpvlu.supabase.co/functions/v1/credits-api/x402/purchase';
const order = { project_id: 'your_project_id', credits: 500 };

const quote = await fetch(url, {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify(order)
});
// quote.status === 402
const paymentRequired = JSON.parse(atob(quote.headers.get('PAYMENT-REQUIRED')));

// 3. Sign the chosen requirements with your wallet (EIP-3009 for USDC), then
//    retry the same request with the signed payload.
const paid = await fetch(url, {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'PAYMENT-SIGNATURE': btoa(JSON.stringify(signedPaymentPayload))
  },
  body: JSON.stringify(order)
});

const receipt = await paid.json();
// {
//   success: true,
//   credits_purchased: 500,
//   new_balance: 500,
//   buyer_id: 'x402:0xAgentWallet...',
//   payer: '0xAgentWallet...',
//   price_paid: 5,
//   currency: 'USDC',
//   transaction: '0xabc...'
// }
// The settlement receipt is also on the PAYMENT-RESPONSE response header.