The starter mirrors the upstream example and bootstraps a ready-to-run Fetch client. To run from the repo instead: clone coinbase/x402, then from the typescript examples root run pnpm install && pnpm build, then cd clients/fetch, copy .env-local to .env, and run pnpm dev.
This is the index.ts the starter generates. It loads your env, creates an x402 client with EVM and SVM schemes, wraps fetch with wrapFetchWithPayment, calls your endpoint, and logs the response body and payment settlement from the PAYMENT-RESPONSE header.
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import { config } from "dotenv";import { x402Client, wrapFetchWithPayment, x402HTTPClient } from "@x402/fetch";import { registerExactEvmScheme } from "@x402/evm/exact/client";import { registerExactSvmScheme } from "@x402/svm/exact/client";import { privateKeyToAccount } from "viem/accounts";import { createKeyPairSignerFromBytes } from "@solana/kit";import { base58 } from "@scure/base";config();const evmPrivateKey = process.env.EVM_PRIVATE_KEY as `0x${string}`;const svmPrivateKey = process.env.SVM_PRIVATE_KEY as string;const baseURL = process.env.RESOURCE_SERVER_URL || "http://localhost:4021";const endpointPath = process.env.ENDPOINT_PATH || "/weather";const url = `${baseURL}${endpointPath}`;/** * Example demonstrating how to use @x402/fetch to make requests to x402-protected endpoints. * * This uses the helper registration functions from @x402/evm and @x402/svm to register * all supported networks for both v1 and v2 protocols. * * Required environment variables: * - EVM_PRIVATE_KEY: The private key of the EVM signer * - SVM_PRIVATE_KEY: The private key of the SVM signer */async function main(): Promise<void> { const evmSigner = privateKeyToAccount(evmPrivateKey); const svmSigner = await createKeyPairSignerFromBytes(base58.decode(svmPrivateKey)); const client = new x402Client(); registerExactEvmScheme(client, { signer: evmSigner }); registerExactSvmScheme(client, { signer: svmSigner }); const fetchWithPayment = wrapFetchWithPayment(fetch, client); console.log(`Making request to: ${url}\n`); const response = await fetchWithPayment(url, { method: "GET" }); const body = await response.json(); console.log("Response body:", body); if (response.ok) { const paymentResponse = new x402HTTPClient(client).getPaymentSettleResponse(name => response.headers.get(name), ); console.log("\nPayment response:", JSON.stringify(paymentResponse, null, 2)); } else { console.log(`\nNo payment settled (response status: ${response.status})`); }}main().catch(error => { console.error(error?.response?.data?.error ?? error); process.exit(1);});
You can test your client against a local server by running the Express example, Hono example, or Next.js example.You can also test your client against a live merchant for free. You will receive a full refund of any tokens that you send, and PayAI will pay for the network fees.
