x402-client - SKILL.md Agent Skill

name: x402-client description: Client for interacting with the x402 payment service when receiving HTTP 402 responses.

X402 Client Skill

Overview

The X402 Client Skill enables seamless interaction with the X402 payment service. When a user's HTTP request returns a 402 status code, this skill will be triggered to handle the authentication process and facilitate secure payment transactions.

Workflow

Verify that dependencies are installed
Verify the private key to use
Verify the target network
Execute the corresponding JS script

Dependencies

npm install https://github.com/second-state/x402-client.git

Get Private Key

Check if there is a .env file in this skill folder
If a .env file is found, verify that it contains the PRIVATE_KEY variable
If no .env file is found, ask the user for a PRIVATE_KEY and create a .env file with that variable

Target Network

The HTTP 402 response will contain an accepts array with the payment methods supported by the target URL
Select the network to use (e.g., base or base-sepolia)
If there are multiple options, ask the user which network to use

Execute Script

After obtaining the TARGET_URL and PRIVATE_KEY, execute the following script:

import { createX402Client } from "x402-client";

const PRIVATE_KEY = "0x<PRIVATE_KEY>";
const TARGET_URL = "<TARGET_URL>";
const NETWORK = "<NETWORK>";

if (!PRIVATE_KEY) throw new Error("Missing PRIVATE_KEY");

const client = await createX402Client({
  chain: NETWORK,
  privateKey: PRIVATE_KEY,
});

const response = await client.fetchWithPayment(TARGET_URL, { method: "GET" });
console.log("Response headers:", Object.fromEntries(response.headers));
console.log("Response body:", await response.text());

const paymentHeader = response.headers.get("x-payment-response");
if (paymentHeader) {
  console.log("Decoded payment response:", client.decodePaymentResponse(paymentHeader));
}

Response

Return the result of the Execute Script to the user.