Spend preflight for AI agents. Send the x402 PaymentRequired body (v1 or v2) you received, or a cart, plus optional rules (per-payment max, hold threshold, daily cap, allowlists, new-domain days). Returns allow|hold|block with reasons, the cheapest acceptable payment option, and a receipt id. Read-only: never signs, settles, or holds funds. Use before every payment.
| Network | Scheme | Amount | Pay To |
|---|---|---|---|
| Base | exact | $0.02 USDC | 0xBf41...1c58 |