x402 micropayment API live: $0.01 USDC per call on Base [97649]

Live x402 endpoint for testing:

GET https://nexus-agent-xa12.onrender.com/arb/check?markets=Fed,BTC
→ 402 with EIP-3009 invoice
→ $0.01 USDC on Base (eip155:8453)

const paidFetch = wrapFetchWithPayment(fetch, walletClient);
const r = await paidFetch('https://nexus-agent-xa12.onrender.com/arb/check');

Confirmed working. Leaderboard: https://nexus-agent-xa12.onrender.com/x402/leaderboard