Scenarios /

Standard payment: /t/ok

EndpointGET https://x402testendpoint.com/t/ok
Kindpay: a correct buyer completes the payment
Quoted price$0.001 in test USDC on Base Sepolia (testnet)
Cost to youNothing. Test USDC has no value.

What the seller does

A well-formed quote for a tenth of a cent. The baseline every buyer should pass.

What a correct buyer does

Pay the quoted amount and receive 200 with a PAYMENT-RESPONSE header.

Why test this

This is the baseline. If a client cannot complete this, nothing else matters; if it can, the remaining scenarios test how it behaves when the seller does not.

Run it

See the quote without paying:

curl -i https://x402testendpoint.com/t/ok

Then point your own client at it, or use the official one:

import { x402Client, x402HTTPClient } from "@x402/core/client";
import { ExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const account = privateKeyToAccount(process.env.BUYER_KEY);
const core = new x402Client().register("eip155:84532", new ExactEvmScheme(account));
const http = new x402HTTPClient(core);

const first = await fetch("https://x402testendpoint.com/t/ok");
const quote = http.getPaymentRequiredResponse((h) => first.headers.get(h));
const headers = http.encodePaymentSignatureHeader(await core.createPaymentPayload(quote));
const paid = await fetch(first.url, { headers });
console.log(paid.status, paid.headers.get("x-test-verdict"));

The wallet needs test USDC on Base Sepolia (testnet) for scenarios that settle. Circle's faucet at https://faucet.circle.com provides it.

What you will see

A correct client ends with HTTP 200, a PAYMENT-RESPONSE header carrying the settlement, and x-test-verdict: pass. The JSON body repeats the transaction hash and payer.

If the payment is rejected, the endpoint answers 402 again with the facilitator's reason in the quote's error field. Look the reason up in the error reference.

How the official client behaves

@x402/core 2.31 with default settings: Reads the quote, signs for 0.001 USDC and receives 200 once the wallet holds test USDC. An unfunded wallet is rejected with invalid_exact_evm_insufficient_balance.

Related errors

Other scenarios