PayAI

PayAI is a hosted facilitator service that simplifies x402 payment processing. Instead of running your own facilitator infrastructure, you can use PayAI’s endpoints to handle payment verification and settlement.

Prerequisites

Node.js and npm installed
A SKALE Chain endpoint
Basic understanding of x402 protocol

Configuration

Environment Variables

Create a .env file with PayAI configuration:

# Facilitator Router Address
RECEIVING_ADDRESS=0xFacilitatorReceivingAddress

# Payment token configuration
PAYMENT_TOKEN_ADDRESS=0x2e08028E3C4c2356572E096d8EF835cD5C6030bD
PAYMENT_TOKEN_NAME="Bridged USDC (SKALE Bridge)"

# SKALE network configuration
NETWORK_CHAIN_ID=324705682

Integration with PayAI

Server Setup
Client Setup

import { Hono } from "hono";
import { serve } from "@hono/node-server";
import { paymentMiddleware, x402ResourceServer } from "@x402/hono";
import { ExactEvmScheme } from "@x402/evm/exact/server";
import { HTTPFacilitatorClient } from "@x402/core/server";
import type { Network } from "@x402/core/types";
import "dotenv/config";

const app = new Hono();

async function main() {
  // Point to PayAI facilitator
  const facilitatorUrl = "https://facilitator.payai.network";
  const receivingAddress = process.env.RECEIVING_ADDRESS as `0x${string}`;
  const paymentTokenAddress = process.env.PAYMENT_TOKEN_ADDRESS as `0x${string}`;
  const paymentTokenName = process.env.PAYMENT_TOKEN_NAME ;
  const networkChainId = process.env.NETWORK_CHAIN_ID;
  const network: Network = `eip155:${networkChainId}`;

  // Initialize PayAI facilitator client
  const facilitatorClient = new HTTPFacilitatorClient({ 
    url: facilitatorUrl 
  });
  
  const resourceServer = new x402ResourceServer(facilitatorClient);
  resourceServer.register("eip155:*", new ExactEvmScheme());

  // Apply payment middleware
  app.use(
    paymentMiddleware(
      {
        "GET /api/data": {
          accepts: [
            {
              scheme: "exact",
              network: network,
              payTo: receivingAddress,
              price: {
                amount: "10000", // 0.01 tokens
                asset: paymentTokenAddress,
                extra: {
                  name: paymentTokenName,
                  version: "1",
                },
              },
            },
          ],
          description: "Premium data access",
          mimeType: "application/json",
        },
      },
      resourceServer
    )
  );

  // Protected endpoint
  app.get("/api/data", (c) => {
    return c.json({
      message: "Premium data unlocked via PayAI!",
      timestamp: new Date().toISOString(),
    });
  });

  const port = 3000;
  serve({ fetch: app.fetch, port }, () => {
    console.log(`Server running on http://localhost:${port}`);
    console.log(`Using PayAI facilitator: ${facilitatorUrl}`);
  });
}

main().catch(console.error);

import { x402Client, x402HTTPClient } from "@x402/core/client";
import { ExactEvmScheme } from "@x402/evm";
import { privateKeyToAccount } from "viem/accounts";
import "dotenv/config";

async function main() {
  // Setup wallet
  const account = privateKeyToAccount(
    process.env.PRIVATE_KEY as `0x${string}`
  );

  // Create x402 client
  const evmScheme = new ExactEvmScheme(account);
  const coreClient = new x402Client().register("eip155:*", evmScheme);
  const httpClient = new x402HTTPClient(coreClient);

  // Access PayAI-protected resource
  const url = "http://localhost:3000/api/data";
  const response = await fetch(url);

  if (response.status === 402) {
    console.log("Payment required, processing via PayAI...");

    const responseBody = await response.json();
    const paymentRequired = httpClient.getPaymentRequiredResponse(
      (name: string) => response.headers.get(name),
      responseBody
    );

    const paymentPayload = await httpClient.createPaymentPayload(
      paymentRequired
    );
    
    const paymentHeaders = httpClient.encodePaymentSignatureHeader(
      paymentPayload
    );

    const paidResponse = await fetch(url, {
      headers: { ...paymentHeaders },
    });

    const data = await paidResponse.json();
    console.log("Data received:", data);
  }
}

main();

Troubleshooting

Connection Issues

If you cannot connect to PayAI:

Verify the facilitator URL is correct
Check network connectivity
Ensure API credentials are valid
Review firewall settings

Payment Failures

Common causes and solutions:

Issue	Solution
Invalid signature	Verify wallet configuration and signing
Insufficient balance	Ensure payer has enough tokens
Network mismatch	Check chain ID matches configuration
Expired authorization	Increase `maxTimeoutSeconds`

Resources

This entity — PayAI — is deployed and activley supporting SKALE. These are 3rd party services that may have their own terms and conditions and privacy polices. Use these services at your own risk. AI and agents is a highly experimental space; the 3rd party software solutions may have bugs or be unaudited. You and your agents and your customers use all 3rd party services chosen at your own risk and per their terms.

Deployment

Smart Contracts

Privacy

x402

MPP

Facilitators

AI Agents

Native Features

Prerequisites

Configuration

Environment Variables

Integration with PayAI

Troubleshooting

Connection Issues

Payment Failures

Resources

​Prerequisites

​Configuration

​Environment Variables

​Integration with PayAI

​Troubleshooting

​Connection Issues

​Payment Failures

​Resources

Prerequisites

Configuration

Environment Variables

Integration with PayAI

Troubleshooting

Connection Issues

Payment Failures

Resources