Webhook Handler

import { createRouter } from '@agentuity/runtime';
import crypto from 'crypto';
import paymentProcessor from '@agent/payment-processor';
import subscriptionHandler from '@agent/subscription-handler';
 
const router = createRouter();
 
router.post('/stripe', async (c) => {
  // Get raw body for signature verification
  const rawBody = await c.req.text();
  const signature = c.req.header('stripe-signature');
 
  // Verify signature
  const secret = process.env.STRIPE_WEBHOOK_SECRET;
  if (!secret || !verifyStripeSignature(rawBody, signature, secret)) { 
    c.var.logger.warn('Invalid webhook signature');
    return c.text('Invalid signature', 401);
  }
 
  const event = JSON.parse(rawBody);
  c.var.logger.info('Webhook received', { type: event.type });
 
  // Process in background, respond immediately
  c.waitUntil(async () => { 
    try {
      switch (event.type) {
        case 'payment_intent.succeeded':
          await paymentProcessor.run({
            paymentId: event.data.object.id,
            amount: event.data.object.amount,
            customerId: event.data.object.customer,
          });
          break;
 
        case 'customer.subscription.updated':
          await subscriptionHandler.run({
            subscriptionId: event.data.object.id,
            status: event.data.object.status,
          });
          break;
 
        default:
          c.var.logger.debug('Unhandled event type', { type: event.type });
      }
    } catch (error) {
      c.var.logger.error('Webhook processing failed', { error, eventType: event.type });
      // Store for retry
      await c.var.kv.set('failed-webhooks', event.id, {
        event,
        error: String(error),
        timestamp: Date.now(),
      }, { ttl: 86400 }); // 24 hours
    }
  });
 
  // Return 200 immediately
  return c.json({ received: true }); 
});
 
function verifyStripeSignature(
  payload: string,
  signature: string | undefined,
  secret: string
): boolean {
  if (!signature) return false;
 
  const parts = signature.split(',').reduce((acc, part) => {
    const [key, value] = part.split('=');
    acc[key] = value;
    return acc;
  }, {} as Record<string, string>);
 
  const timestamp = parts['t'];
  const expectedSig = parts['v1'];
 
  const signedPayload = `${timestamp}.${payload}`;
  const computedSig = crypto
    .createHmac('sha256', secret)
    .update(signedPayload)
    .digest('hex');
 
  return crypto.timingSafeEqual(
    Buffer.from(expectedSig),
    Buffer.from(computedSig)
  );
}
 
export default router;

import slackHandler from '@agent/slack-handler';
 
router.post('/slack', async (c) => {
  // Slack retries on failure - skip duplicates
  if (c.req.header('x-slack-retry-num')) {
    return c.text('OK');
  }
 
  const rawBody = await c.req.text();
 
  // Verify Slack signature
  const timestamp = c.req.header('x-slack-request-timestamp');
  const signature = c.req.header('x-slack-signature');
  const secret = process.env.SLACK_SIGNING_SECRET;
 
  if (!verifySlackSignature(rawBody, timestamp, signature, secret)) {
    return c.text('Invalid signature', 401);
  }
 
  const payload = JSON.parse(rawBody);
 
  // Handle URL verification challenge
  if (payload.type === 'url_verification') {
    return c.text(payload.challenge);
  }
 
  // Process event in background
  c.waitUntil(async () => { 
    await slackHandler.run(payload);
  });
 
  return c.text('OK');
});