three.ws x402 Facilitator

Verify and settle x402 v2 micropayments (USDC) on EVM chains. Powers https://three.ws/pay.

Live endpoint: https://facilitator.three.ws

Supported chains

Chain	Network	USDC address
Base	eip155:8453	0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
Arbitrum	eip155:42161	0xaf88d065e77c8cC2239327C5EDb3A432268e5831
Ethereum	eip155:1	0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48

Quick start

git clone https://github.com/nirholas/x402-facilitator
cd x402-facilitator
cp .env.example .env
# Set FACILITATOR_PRIVATE_KEY and fund it with ETH on each chain
npm install
npm run dev

API

Method	Endpoint	Description
GET	/health	Liveness + chain connectivity
GET	/info	Facilitator metadata
GET	/supported	Supported payment kinds
POST	/verify	Verify EIP-3009 signature off-chain
POST	/settle	Settle payment on-chain
GET	/balances	Gas + USDC balances per chain
GET	/fees	Estimated settlement cost
GET	/status/:txHash	Transaction status
GET	/.well-known/x402	x402 discovery

x402Version 2 payload format

{
  "x402Version": 2,
  "scheme": "exact",
  "network": "eip155:8453",
  "payload": {
    "signature": "0x...",
    "authorization": {
      "from": "0x<payer>",
      "to": "0x<payTo>",
      "value": "1000",
      "validAfter": "0",
      "validBefore": "1234567890",
      "nonce": "0x<32 random bytes>"
    }
  }
}

Deployment

Deploy to Railway — set FACILITATOR_PRIVATE_KEY and fund the address with ETH on Base, Arbitrum, and Ethereum for gas. Add custom domain facilitator.three.ws.

Operator

three.ws — AI agent infrastructure