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Overview

The auth-capture scheme for x402 v2 uses the audited Commerce Payments Protocol (AuthCaptureEscrow + token collectors) directly, no fork. The client signs a single signature (ERC-3009 or Permit2). The facilitator submits it, either locking funds in escrow for later capture (two-phase) or sending them directly to the receiver with refund capability (single-shot). Unlike exact, which has no mechanism for returning funds, auth-capture supports returning funds to the client through void, refund, and reclaim.

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Settlement Paths

The scheme supports two settlement paths, selected via extra.autoCapture:

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Two-phase (autoCapture: false, default)

1

Authorize

The facilitator submits the client’s authorization, locking funds in escrow via AuthCaptureEscrow.authorize(). The token collector executes the client’s signature (ERC-3009 receiveWithAuthorization or Permit2 permitTransferFrom) to pull tokens into escrow.
2

Resource Delivered

Server returns the resource (HTTP 200).
3

Capture or Void

The captureAuthorizer can capture (capture funds to the receiver) or void (return escrowed funds to the client). Capture conditions are policy-defined per captureAuthorizer (time-locked, arbiter-approved, etc.).
4

Reclaim

If captureDeadline passes without capture, the client can reclaim funds directly from the escrow without captureAuthorizer involvement.
5

Refund (Optional)

After capture, the captureAuthorizer can refund within the refundDeadline window.

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Single-shot (autoCapture: true)

1

Charge

The facilitator submits the client’s authorization, sending funds directly to the receiver via AuthCaptureEscrow.charge(). No escrow hold.
2

Resource Delivered

Server returns the resource (HTTP 200).
3

Refund (Optional)

The captureAuthorizer can refund within the refundDeadline window.
No capture, void, or reclaim, funds are never held in escrow.

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Visual Flow

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Exact Payment (Immediate Settlement)

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auth-capture (Two-phase)

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Key Differences

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CaptureAuthorizer

The captureAuthorizer is the address that may call authorize, capture, void, refund, or charge on a payment. The escrow contract gates those operations on msg.sender. In x402’s facilitator-submits flow that means either the facilitator’s EOA, or any smart contract that ends up calling the escrow (for example, an arbiter contract with dispute logic or a multisig).

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vs Exact Scheme

The auth-capture scheme adds an authorization step before settlement (or refundability for single-shot). For simple immediate payments where trust and refundability aren’t concerns, the exact scheme remains more efficient.

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Next Steps

Wire Format

PaymentRequirements and PaymentPayload shapes for EIP-3009 and Permit2.

Verification and Settlement

The 13-step verification flow, settlement logic, and error codes.

PaymentInfo Struct

On-chain struct, expiry ordering, and safety guarantees.

SDK Overview

Build your first auth-capture payment flow.

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References