What is a Facilitator?

In the x402 protocol, a facilitator is a service that verifies and settles crypto payments on behalf of API servers. Instead of running your own blockchain nodes and implementing payment verification, you delegate that to us.

How It Works

Quickstart

1. Register as a Provider

curl -X POST https://archtools.dev/api/v1/facilitator/register \
  -H "Content-Type: application/json" \
  -d '{
    "name": "My API",
    "email": "[email protected]",
    "walletAddress": "0xYourWalletAddress",
    "networks": ["eip155:8453"]
  }'

Save the apiKey from the response — it's only shown once.

2. Verify Payments

When a client sends an x402 payment to your API, forward it to us for verification:

curl -X POST https://archtools.dev/api/v1/facilitator/verify \
  -H "Authorization: Bearer fac_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "payment": "<base64-encoded-payment-payload>",
    "paymentDetails": {
      "scheme": "exact",
      "network": "eip155:8453",
      "maxAmountRequired": "1000",
      "resource": "https://myapi.com/v1/endpoint",
      "payTo": "0xYourWalletAddress",
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
    }
  }'

3. Settle Payments

After fulfilling the request, settle the payment on-chain:

curl -X POST https://archtools.dev/api/v1/facilitator/settle \
  -H "Authorization: Bearer fac_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "payment": "<base64-encoded-payment-payload>",
    "paymentDetails": {
      "scheme": "exact",
      "network": "eip155:8453",
      "maxAmountRequired": "1000",
      "resource": "https://myapi.com/v1/endpoint",
      "payTo": "0xYourWalletAddress",
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
    }
  }'

4. Check Your Dashboard

curl https://archtools.dev/api/v1/facilitator/dashboard \
  -H "Authorization: Bearer fac_your_api_key"

Express.js Integration Example

import express from "express";
import axios from "axios";

const FACILITATOR_URL = "https://archtools.dev/api/v1/facilitator";
const FACILITATOR_KEY = process.env.ARCH_FACILITATOR_KEY;
const MY_WALLET = process.env.MY_WALLET_ADDRESS;

// Middleware: check for x402 payment
async function x402Middleware(req, res, next) {
  const payment = req.headers["x-payment"];

  if (!payment) {
    // Return 402 Payment Required
    return res.status(402).json({
      x402Version: 1,
      accepts: [{
        scheme: "exact",
        network: "eip155:8453",
        maxAmountRequired: "1000", // 0.001 USDC
        resource: `https://myapi.com${req.path}`,
        payTo: MY_WALLET,
        asset: "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        maxTimeoutSeconds: 60,
      }],
    });
  }

  // Verify payment with Arch Tools
  const { data } = await axios.post(`${FACILITATOR_URL}/verify`, {
    payment,
    paymentDetails: {
      scheme: "exact",
      network: "eip155:8453",
      maxAmountRequired: "1000",
      resource: `https://myapi.com${req.path}`,
      payTo: MY_WALLET,
      asset: "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    },
  }, {
    headers: { Authorization: `Bearer ${FACILITATOR_KEY}` },
  });

  if (!data.isValid) {
    return res.status(402).json({ error: "payment_invalid", reason: data.invalidReason });
  }

  // Payment verified — proceed with request
  req.x402Payment = payment;
  next();
}

// After fulfilling request, settle payment
async function settleAfterResponse(req) {
  if (!req.x402Payment) return;
  await axios.post(`${FACILITATOR_URL}/settle`, {
    payment: req.x402Payment,
    paymentDetails: {
      scheme: "exact",
      network: "eip155:8453",
      maxAmountRequired: "1000",
      resource: `https://myapi.com${req.path}`,
      payTo: MY_WALLET,
      asset: "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    },
  }, {
    headers: { Authorization: `Bearer ${FACILITATOR_KEY}` },
  });
}

const app = express();
app.use(express.json());

app.post("/v1/my-tool", x402Middleware, async (req, res) => {
  // Do your thing
  const result = { ok: true, data: "Hello, paying customer!" };
  res.json(result);

  // Settle in background (don't block response)
  settleAfterResponse(req).catch(console.error);
});

app.listen(3000);

API Reference

POST /api/v1/facilitator/register

Register as a new facilitator provider. No auth required.

Field	Type	Required	Description
name	string	✅	Your API/company name
email	string	✅	Contact email
walletAddress	string	✅	EVM wallet for receiving payments (0x...)
webhookUrl	string	—	URL for payment event webhooks
networks	string[]	—	Networks to enable (default: ["eip155:8453"])
endpoints	object	—	Your endpoints and pricing

POST /api/v1/facilitator/verify

Verify an x402 payment. Requires facilitator API key.

Field	Type	Description
payment	string	Base64-encoded x402 payment payload
paymentDetails.scheme	string	"exact"
paymentDetails.network	string	Chain ID (e.g. "eip155:8453")
paymentDetails.maxAmountRequired	string	Minimum amount in atomic units
paymentDetails.resource	string	URL of the resource being paid for
paymentDetails.payTo	string	Your wallet address
paymentDetails.asset	string	Token contract address

POST /api/v1/facilitator/settle

Settle a verified payment on-chain. Same request body as verify.

GET /api/v1/facilitator/dashboard

Get your payment stats, revenue, and recent transactions. Requires facilitator API key.

GET /api/v1/facilitator/networks

List all supported networks. No auth required.

GET /api/v1/facilitator/health

Check facilitator service status. No auth required.

Supported Networks

Network	Chain ID	Token	Settlement Time
Base	eip155:8453	USDC	~2 seconds
Ethereum	eip155:1	USDC	~12 seconds
Arbitrum	eip155:42161	USDC	~2 seconds
Polygon	eip155:137	USDC	~2 seconds
Optimism	eip155:10	USDC	~2 seconds
Avalanche	eip155:43114	USDC	~2 seconds
Base Sepolia (testnet)	eip155:84532	USDC	~2 seconds

Pricing

Simple, transparent pricing. We take a small percentage of each settled payment.

Tier	Monthly Payments	Fee
Free	Up to 100	0% (try it free)
Growth	101 – 10,000	1.0%
Scale	10,001 – 100,000	0.5%
Enterprise	100,000+	Custom (contact us)

Gas fees are included — we pay for settlement. No hidden costs.

Why Use Arch Tools as Your Facilitator?

• Zero infrastructure — No blockchain nodes, no gas management, no key custody
• Multi-network — Base, Ethereum, Arbitrum, Polygon, Optimism, Avalanche
• Battle-tested — Built on the same x402 infrastructure that powers Arch Tools' own 50+ API endpoints
• Replay protection — Redis-backed nonce deduplication + on-chain nonce verification
• EIP-3009 native — Full transferWithAuthorization support for gasless USDC payments
• Real-time dashboard — Track every payment, fee, and settlement via API
• x402 compliant — 100% compatible with the x402 protocol spec