x402

How the paid call works

• 1 — GET /api with no payment → HTTP 402 with the offer: amount, asset (USDC, eip155:8453), payTo, nonce, scheme exact.
• 2 — the client signs the payment and repeats the call with the payment signature header.
• 3 — the door verifies and settles through the facilitator, answers the call and returns a signed receipt with decision_id, reason_code and rule_set_version.
• 4 — GET /x402/receipt/{nonce} resolves the receipt, forever.