Circle Affiliate Program: Complete Integration Guide | AffiliateBase

// Example: Next.js API route for Circle webhooks
import { headers } from 'next/headers';
import crypto from 'crypto';
import { AffiliateBase } from '@affiliatebase/sdk';

const affiliateBase = new AffiliateBase({
  apiKey: process.env.AFFILIATEBASE_API_KEY!,
});

export async function POST(request: Request) {
  const body = await request.text();
  const signature = headers().get('x-circle-signature')!;
  
  // Verify webhook signature
  const expectedSignature = crypto
    .createHmac('sha256', process.env.CIRCLE_WEBHOOK_SECRET!)
    .update(body)
    .digest('hex');
  
  if (signature !== expectedSignature) {
    return new Response('Invalid signature', { status: 401 });
  }
  
  const event = JSON.parse(body);
  
  // Handle different event types
  switch (event.type) {
    case 'member.created':
      // Only track if member has a paid subscription
      if (event.data.member.subscription_id) {
        await affiliateBase.trackConversion({
          affiliateId: event.data.member.metadata?.affiliateId,
          type: 'membership_signup',
          amount: event.data.member.subscription?.price,
          currency: event.data.member.subscription?.currency,
          customerId: event.data.member.id,
          subscriptionId: event.data.member.subscription_id,
          metadata: {
            community_id: event.data.member.community_id,
            membership_tier: event.data.member.membership_tier,
          },
        });
      }
      break;
      
    case 'subscription.created':
      await affiliateBase.trackConversion({
        affiliateId: event.data.subscription.metadata?.affiliateId,
        type: 'subscription',
        amount: event.data.subscription.price,
        currency: event.data.subscription.currency,
        customerId: event.data.subscription.member_id,
        subscriptionId: event.data.subscription.id,
        metadata: {
          community_id: event.data.subscription.community_id,
          plan_name: event.data.subscription.plan_name,
        },
      });
      break;
      
    case 'subscription.updated':
      // Track subscription upgrades/downgrades
      if (event.data.subscription.previous_price !== event.data.subscription.price) {
        await affiliateBase.trackConversion({
          affiliateId: event.data.subscription.metadata?.affiliateId,
          type: 'subscription_upgrade',
          amount: event.data.subscription.price - event.data.subscription.previous_price,
          currency: event.data.subscription.currency,
          customerId: event.data.subscription.member_id,
          subscriptionId: event.data.subscription.id,
        });
      }
      break;
  }
  
  return new Response(JSON.stringify({ received: true }), { status: 200 });
}