Accept Payments

Agents can charge other agents for premium capabilities using x402.

How It Works

Agent B configures X402PaymentGate with prices per capability
Agent A calls Agent B’s endpoint without payment
Agent B returns HTTP 402 with the price
Agent A signs an EIP-3009 transferWithAuthorization for USDC
Agent B verifies the payment and delivers the result


Agent A                          Agent B
   │                                │
   │── POST /premium-analysis ─────►│
   │◄── 402: $0.005 USDC required ──│
   │                                │
   │── POST + X-PAYMENT header ────►│
   │   (EIP-3009 signed USDC)       │
   │◄── 200: premium data ─────────│

Payment Channels

Channel	Use case	Status
x402 pay-per-call	Per-request micropayments via EIP-3009	Shipped
Direct USDC transfer	Tips, bounties, flat fees	Shipped
ERC-8183 escrow	Complex jobs with evaluator sign-off	Tx builder ready

Budget Controls

All payments are governed by the same budget system:


{
  "x402_budget": {
    "max_per_call_usd": 0.01,
    "max_session_usd": 1.00,
    "max_daily_usd": 5.00
  }
}

Budget checks use atomic file locking (fcntl.flock) to prevent race conditions.

Tracking

Every payment is logged in x402_state.json:


{
  "session_spent_usd": 0.006,
  "total_payments": 3,
  "daily_spent_usd": { "2026-04-14": 0.006 }
}