@whop-x402

An open-source, framework-agnostic x402-compatible adapter that allows Node.js/TypeScript-based AI agents to accept payments via Whop (subscriptions, memberships, digital goods) and automatically route native revenue into BNB Chain PancakeSwap on-chain buybacks.

Features

• x402 protocol support: Emits challenge payloads compatible with the x402 agent-to-agent protocol.
• On-chain routing: Executes native BNB swaps for utility tokens on PancakeSwap V2 (BSC).
• Price Oracle: Automatic CoinGecko USD-to-BNB price tracking.
• Webhook validation: Secure HMAC-SHA256 signature verification of Whop payments.
• Event hooks: Typed Node EventEmitter callbacks for custom triggers.

Installation

npm install @whop-x402
# or
bun add @whop-x402

Quick Start (Express Webhook Example)

Here is how to set up the adapter with an Express server to monetize your AI agent:

import Express from 'express';
import WhopX402Adapter from '@whop-x402';

const app = Express();
app.use(Express.raw({ type: 'application/json' })); // raw body is required for HMAC validation

const adapter = new WhopX402Adapter(
  {
    apiKey: process.env.WHOP_API_KEY!,
    webhookSecret: process.env.WHOP_WEBHOOK_SECRET!,
  },
  {
    rpcUrl: process.env.BSC_RPC_URL || 'https://bsc-dataseed.binance.org/',
    chainId: 56, // 56 for Mainnet, 97 for Testnet
    walletPrivateKey: process.env.WALLET_PRIVATE_KEY!,
    tokenAddress: process.env.BUYBACK_TOKEN_ADDRESS!, // Target agent utility token
    buybackPercentage: 100, // Swap 100% of revenue to token
    slippagePercentage: 0.5,
  }
);

// Register Event Hooks
adapter.on('payment_received', (event) => {
  console.log(`💰 Payment of ${event.amountCents} cents received from ${event.payer}`);
});

adapter.on('buyback_executed', (event) => {
  console.log(`🔄 Buyback Executed: Swapped ${event.amountBNB} BNB. Tx Hash: ${event.txHash}`);
});

adapter.on('buyback_failed', (event) => {
  console.error(`❌ Buyback Failed: ${event.error}`);
});

// Webhook Ingestion Route
app.post('/whop-webhook', async (req, res) => {
  const signature = req.headers['x-whop-signature'] as string;
  if (!signature) {
    return res.status(400).send('Missing x-whop-signature header');
  }

  // Pass raw body string and header signature to the adapter
  const rawBody = req.body.toString('utf8');
  const result = await adapter.handlePaymentWebhook(rawBody, signature);

  if (!result.success) {
    return res.status(400).json(result);
  }

  return res.json(result);
});

app.listen(3000, () => console.log('Agent payment gateway active on port 3000'));

Fetch.ai & Agentverse

The adapter is framework-agnostic, so it plugs into any Fetch.ai agent stack. Because the ASI:One Chat Protocol and uAgents run in Python, the recommended topology for a Node.js agent is:

• TypeScript webhook service (examples/agentverse-webhook-agent.ts) — an Express server exposing GET /status, GET /checkout (returns the Whop checkout / x402 payment challenge), POST /whop-webhook (HMAC-verified, triggers the PancakeSwap buyback), and GET /proof (latest on-chain tx hash). Deploy it and expose it with a tunnel (cloudflared tunnel --url http://localhost:8080).
• Python chat agent (../python/examples/agentverse_chat_agent.py) — an ASI:One Chat Protocol uAgent that hands buyers the checkout link and surfaces the buyback proof.

Veridex Agent Fabric Integration

We also provide a fully-equipped, production-grade example using our core framework @veridex/agents:

• Veridex Chat Agent (examples/veridex-chat-agent.ts) — A conversational AI agent constructed with the declarative createAgent factory. It wraps the payment adapter inside a safe, typed Tool (create_checkout_link) and implements on-chain proof retrieval (get_latest_buyback_proof) out of the box!

To run the Veridex Chat Agent:

bun run examples/veridex-chat-agent.ts

To run the standalone Webhook agent:

bun run examples/agentverse-webhook-agent.ts

License

MIT License.