@x402/fetch Example Client

Example client demonstrating how to use @x402/fetch to make HTTP requests to endpoints protected by the x402 payment protocol.

import { x402Client, wrapFetchWithPayment } 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";

const client = new x402Client();
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
registerExactSvmScheme(client, { signer: (await createKeyPairSignerFromBytes(base58.decode(process.env.SVM_PRIVATE_KEY))) });

const fetchWithPayment = wrapFetchWithPayment(fetch, client);

const response = await fetchWithPayment("http://localhost:4021/weather");
console.log(await response.json());

Prerequisites

• Node.js v20+ (install via nvm)
• pnpm v10 (install via pnpm.io/installation)
• A running x402 server (see express server example)
• Valid EVM and/or SVM private keys for making payments

Setup

1. Install and build all packages from the typescript examples root:

cd ../../
pnpm install && pnpm build
cd clients/fetch

2. Copy .env-local to .env and add your private keys:

cp .env-local .env

Required environment variables:

• EVM_PRIVATE_KEY - Ethereum private key for EVM payments
• SVM_PRIVATE_KEY - Solana private key for SVM payments

3. Run the client:

pnpm start

Next Steps

See Advanced Examples for builder pattern registration, payment lifecycle hooks, and network preferences.