Skip to main content
POST
Verify an x402 payment

Authorizations

Authorization
string
header
required

Bearer token authentication with a Circle API key. Use this for production settlement after claiming your Facilitator Service seller account.

Body

application/json
x402Version
enum<integer>
required

x402 protocol version. Facilitator Service supports version 2.

Available options:
2
paymentPayload
object
required

x402 v2 payment payload. Includes the payment terms the buyer accepted and the signed EIP-3009 authorization that authorizes the USDC transfer.

paymentRequirements
object
required

Payment terms the seller advertises for an x402 resource. Facilitator Service validates that the buyer's authorization matches these requirements.

Response

Verification result

isValid
boolean
required

Whether the payload passed every check Facilitator Service runs before submission.

Example:

true

payer
string
required

Buyer address recovered from the signed authorization. Always rendered, including on invalid results, so callers can correlate.

Example:

"0x9aE2..."

invalidReason
enum<string>

Reason code. Present when isValid is false.

Available options:
invalid_x402_version,
unsupported_scheme,
invalid_network,
invalid_payment_requirements,
invalid_payload,
invalid_exact_evm_payload_recipient_mismatch,
invalid_exact_evm_payload_authorization_value_mismatch,
invalid_exact_evm_payload_authorization_valid_after,
invalid_exact_evm_payload_authorization_valid_before,
invalid_exact_evm_payload_signature,
invalid_transaction_state,
insufficient_funds
Example:

"invalid_exact_evm_payload_signature"