# Step 1: get payment requirements
curl -i https://api.offbase.xyz/v1/intel/whale-tracker

# HTTP/1.1 402 Payment Required
# PAYMENT-REQUIRED: <base64-encoded PaymentRequired>
# { "x402Version": 2, "accepts": [...], "sessionId": "0x..." }

# Step 2: pay on Base mainnet (USDC or ETH to vault address)
# Your wallet sends USDC transfer to the vault shown in PaymentRequired.

# Step 3: retry with payment proof
curl https://api.offbase.xyz/v1/intel/whale-tracker \
  -H "X-Payment-Tx-Hash: 0x..." \
  -H "X-Payment-Session: 0x..." \
  -H "X-Wallet-Address: 0x..."

# 200 OK — intelligence data returned

npm install @x402/axios @x402/evm viem

import { wrapAxiosWithPayment, x402Client } from "@x402/axios";
import { ExactEvmScheme } from "@x402/evm/exact/client";
import { UptoBatchEvmScheme } from "@x402/evm/batch/client";
import { privateKeyToAccount } from "viem/accounts";
import axios from "axios";

const account = privateKeyToAccount(process.env.PRIVATE_KEY as `0x${string}`);

const client = new x402Client();
// Register Base mainnet payment handlers
client.register("eip155:8453", new ExactEvmScheme(account));           // exact
client.register("eip155:8453", new UptoBatchEvmScheme(account));        // upto + batch

const api = wrapAxiosWithPayment(
  axios.create({ baseURL: "https://api.offbase.xyz/v1" }),
  client
);

// Auto-handles 402 → signs payment → retries
const { data } = await api.get("/intel/whale-tracker");
// data.items → WalletMovement[]