Quickstart with AgentCash

npm install @agentcash/fetch @agentcash/networks @solana/kit viem

import { privateKeyToAccount } from "viem/accounts";
import { generateKeyPairSigner } from "@solana/kit";
import { executeFetch, PaymentProtocol } from "@agentcash/fetch";
import { Network } from "@agentcash/networks";

const baseUrl = "https://x402.rye.com";

// AgentCash requires both wallets in the type even for an EVM-only flow.
const evm = privateKeyToAccount(process.env.AGENT_PRIVATE_KEY as `0x${string}`);
const svm = await generateKeyPairSigner();

const params = {
  paymentProtocol: PaymentProtocol.X402,
  paymentNetwork: Network.BASE,
};

// 1. Create a checkout intent — pays $0.02 over x402 automatically.
const create = await executeFetch(
  {
    url: `${baseUrl}/v1/checkout-intents`,
    method: "POST",
    headers: {},
    body: JSON.stringify({
      productUrl: "https://shop.example.com/running-shoes",
      quantity: 1,
      buyer: {
        firstName: "Jane",
        lastName: "Doe",
        email: "jane@example.com",
        phone: "+14155551234",
        address1: "123 Market St",
        city: "San Francisco",
        province: "CA",
        country: "US",
        postalCode: "94103",
      },
    }),
  },
  { wallets: { evm, svm }, params, pickProtocol: async () => PaymentProtocol.X402 },
);
const created = await create.response.json();
const intentId = created.id;
// create.paymentInfo.payment.transactionHash is the on-chain settle tx

// 2. Poll for the offer — free, no signature required.
async function pollUntil(targetState: string) {
  while (true) {
    const r = await fetch(`${baseUrl}/v1/checkout-intents?id=${intentId}`, {
      headers: { "X-Wallet-Address": evm.address },
    });
    const intent = await r.json();
    if (intent.state === targetState || intent.state === "failed") return intent;
    await new Promise((res) => setTimeout(res, 3000));
  }
}

const ready = await pollUntil("awaiting_confirmation");
if (ready.state === "failed") throw new Error(ready.failureReason?.message);

// 3. Inspect the offer and decide whether to proceed.
const totalSubunits = ready.offer.cost.total.amountSubunits;
const budgetSubunits = 15000; // $150.00
if (totalSubunits > budgetSubunits) throw new Error("over budget");

// 4. Confirm — pays purchase total + $0.03 over x402 in a single signed authorization.
await executeFetch(
  {
    url: `${baseUrl}/v1/checkout-intents/confirm`,
    method: "POST",
    headers: {},
    body: JSON.stringify({
      id: intentId,
      paymentMethod: { type: "x402", network: "base" },
    }),
  },
  { wallets: { evm, svm }, params, pickProtocol: async () => PaymentProtocol.X402 },
);

// 5. Poll for completion.
const final = await pollUntil("completed");
console.log("order placed:", final.orderId);