x402-facilitator
x402 payment facilitator — verifies and settles EIP-3009 micropayments multichain. v2 facilitator.
In the AI payments ecosystem
x402-facilitator is an early-stage TypeScript project in the AI payments / x402 ecosystem, focused on agent, agent-skills, claude, coinbase. It currently has 5 GitHub stars and 0 forks, and sits alongside related tools like x402-payments-mcp, x402-deploy, modelcontextprotocol.name, vscode-x402, image-analysis-mcp, x402charity.
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
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