Settle

Execute the on-chain USDC transfer after serving the response.

POST /api/x402/settle executes the on-chain USDC transfer after your handler has served the response. The withPayment() middleware calls this automatically in the background.

When it’s called

Settle runs after your handler returns, so the client receives your data immediately without waiting for blockchain confirmation.

Client receives response → settle() runs in background → USDC transfers on Arc

What it does

1. Decodes the payment payload
2. Calls transferWithAuthorization on the Arc USDC contract
3. Waits for confirmation
4. Returns the transaction hash

Response

{
  "success": true,
  "txHash": "0x1c07e4c7...",
  "network": "eip155:5042002"
}

The settle call is fire-and-forget from your API’s perspective. If it fails, the payload is still valid and can be retried. Nonces prevent double-spending.