Node.js Example

// Using Express.js
const express = require('express');
const crypto = require('crypto');
const bodyParser = require('body-parser');

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

// Your FundPay secret key
const SECRET_KEY = process.env.FUNDPAY_SECRET_KEY;

// Webhook endpoint
app.post('/webhooks/fundpay', async (req, res) => {
  try {
    const payload = req.body;
    console.log('Received webhook:', payload);
    
    // Check transaction type
    if (payload.transaction_type === 'withdrawal') {
      // Verify signature for withdrawal webhooks
      const receivedSignature = payload.signature;
      
      // Create a copy of the payload without the signature for verification
      const payloadForVerification = {...payload};
      delete payloadForVerification.signature;
      
      // Sort keys alphabetically
      const sortedPayload = {};
      Object.keys(payloadForVerification).sort().forEach(key => {
        sortedPayload[key] = payloadForVerification[key];
      });
      
      // Create string to sign
      const stringToSign = Object.entries(sortedPayload)
        .map(([key, value]) => `${key}=${value}`)
        .join('&');
      
      // Generate signature
      const calculatedSignature = crypto
        .createHmac('sha256', SECRET_KEY)
        .update(stringToSign)
        .digest('hex');
      
      // Verify signature
      if (calculatedSignature !== receivedSignature) {
        console.error('Invalid signature');
        return res.status(400).send('Invalid signature');
      }
    }
    
    // Process the webhook based on transaction type and status
    if (payload.transaction_type === 'deposit') {
      await processDepositWebhook(payload);
    } else if (payload.transaction_type === 'withdrawal') {
      await processWithdrawalWebhook(payload);
    }
    
    // Acknowledge receipt of webhook
    res.status(200).send('Webhook received');
  } catch (error) {
    console.error('Error processing webhook:', error);
    res.status(500).send('Error processing webhook');
  }
});

async function processDepositWebhook(payload) {
  // Update your database based on deposit status
  const { reference_id, status, amount, transaction_id } = payload;
  
  // Example: Update order status in your database
  // await db.orders.updateStatus(reference_id, status);
  
  console.log(`Updated deposit status for ${reference_id} to ${status}`);
}

async function processWithdrawalWebhook(payload) {
  // Update your database based on withdrawal status
  const { reference_id, status, amount, transaction_id } = payload;
  
  // Example: Update withdrawal request in your database
  // await db.withdrawals.updateStatus(reference_id, status);
  
  console.log(`Updated withdrawal status for ${reference_id} to ${status}`);
}

app.listen(3000, () => {
  console.log('Webhook server running on port 3000');
});