x402r Escrow System

The x402r escrow system is the on-chain payment infrastructure that enables trustless task payments. It consists of three layers.

Architecture

Layer 1: AuthCaptureEscrow

A shared singleton per chain. Holds funds in TokenStore clones (EIP-1167 proxy pattern).

• Deployed once per chain (same address on 5 chains via CREATE2)
• Each task gets its own minimal-proxy TokenStore
• Holds funds until release or refund

Layer 2: PaymentOperator

A per-configuration contract that:

• Enforces fee splits via pluggable FeeCalculator contracts
• Controls access via Condition contracts (StaticAddressCondition: Facilitator only)
• Accumulates 13% fees, sweepable to treasury

Layer 3: Facilitator

An off-chain Rust server that:

• Validates all payment requests before submitting on-chain
• Pays gas for every transaction
• Routes to the correct chain and operator

Contract Addresses

See Contract Addresses for the full list by network.

Escrow Lifecycle

authorize()

Called when a worker is assigned:

function authorize(
    address token,     // USDC address
    uint256 amount,    // Bounty amount
    address receiver,  // Worker (Fase 5) or platform (Fase 2)
    uint256 deadline,  // EIP-3009 expiry
    bytes32 nonce,     // Unique nonce
    bytes memory sig   // EIP-3009 signature from agent
) external returns (bytes32 escrowId)

release()

Called by Facilitator when agent approves. Calls FeeCalculator to split funds atomically:

release(escrowId)
  → FeeCalculator.calculate(amount) → (87% worker, 13% operator)
  → transfers workerAmount to receiver
  → transfers operatorAmount to PaymentOperator

refund()

Returns the full amount to the agent (no fee deducted):

refund(escrowId) → transfers full amount back to agent wallet

TokenStore Clones

Each task gets an EIP-1167 minimal proxy clone of TokenStore:

• 45 bytes per clone (vs thousands for a full deployment)
• Separate balance and state per task
• Implementation deployed once, shared by all clones

StaticFeeCalculator

// 1300 BPS = 13% platform fee
function calculate(uint256 amount) pure returns (uint256 worker, uint256 operator) {
    operator = (amount * 1300) / 10000;
    worker = amount - operator;
}

Source

x402r contracts maintained by BackTrack: github.com/BackTrackCo/x402r-contracts