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Documentation Index

Fetch the complete documentation index at: https://docs.x402r.org/llms.txt

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This is the on-chain Solidity struct. The JSON payload omits the payer field; the facilitator recovers it from the signature at settlement time. Wire-format extra uses spec-level field names; the on-chain struct keeps canonical names so the EIP-712 typehash matches the AuthCaptureEscrow contract byte-for-byte. 
struct PaymentInfo {
    address operator;            // = extra.captureAuthorizer
    address payer;               // payload-derived
    address receiver;            // = requirements.payTo
    address token;               // = requirements.asset
    uint120 maxAmount;           // = requirements.amount
    uint48  preApprovalExpiry;   // = now + maxTimeoutSeconds (client-derived)
    uint48  authorizationExpiry; // = extra.captureDeadline
    uint48  refundExpiry;        // = extra.refundDeadline
    uint16  minFeeBps;
    uint16  maxFeeBps;
    address feeReceiver;         // = extra.feeRecipient
    uint256 salt;                // = payload.salt (client-generated, fresh per request)
}

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Expiry Ordering

The contract enforces: preApprovalExpiry <= authorizationExpiry <= refundExpiry
ExpiryWire fieldEnforced AtEffect
preApprovalExpiryderivedauthorize() / charge()Blocks settlement after this time
authorizationExpirycaptureDeadlinecapture()Blocks capture; allows reclaim()
refundExpiryrefundDeadlinerefund()Blocks refund requests

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Safety Guarantees

The escrow contract enforces invariants on-chain:

No Overcharging

The client-signed maxAmount caps the settlement amount. Attempts to exceed the limit revert.

Replay Prevention

Each payment has a unique nonce derived from (chainId, escrowAddress, paymentInfoHash). The nonce is consumed on-chain at settlement.

Payer Reclaim

After captureDeadline, the payer can reclaim escrowed funds directly without captureAuthorizer approval.

Fee Bounds

Min/max fee bounds in PaymentInfo are client-signed and enforced on-chain. The captureAuthorizer must respect these limits.
CaptureAuthorizer Trust Required: The captureAuthorizer controls when and how much to capture. Choose with intent and understand the capture policy. See PaymentOperator for examples.

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Next Steps

Wire Format

Where each PaymentInfo field comes from on the wire.

Verification and Settlement

The 13-step verification flow that enforces these invariants.