In-app purchases for iOS, Android and Capacitor apps Put a buy button in your app. We get the rest sorted.

// 1. After the store's payment sheet closes
const { transaction } = await SpruikIap.purchase({ productId: 'pro_monthly' });

// 2. Hand it to Vend16. We check it with Apple or Google.
await vend16.handle(transaction, user.id, SpruikIap);

// 3. Unlock features from our answer, never the phone's
const { active_product_ids } = await vend16.subscriber(user.id);
if (active_product_ids.includes('pro_monthly')) unlockPro();

# Any platform: send the store's token straight to us
curl https://vend16.com/v1/receipts \
  -H "Authorization: Bearer pk_your_public_key" \
  -d '{"platform":"ios","token":"<StoreKit 2 JWS>","appUserId":"user_42"}'

# Then ask what this user is entitled to
curl https://vend16.com/v1/subscribers/user_42 \
  -H "Authorization: Bearer pk_your_public_key"

// Your server hears about every change, even when the app is closed
app.post('/hooks/vend16', (req, res) => {
  if (!verifySignature(req)) return res.sendStatus(401);
  const { type, app_user_id, data } = req.body;
  if (type === 'renewal')    extendAccess(app_user_id, data.expires_at);
  if (type === 'refund')     takeBack(app_user_id, data.product_id);
  if (type === 'expiration') downgrade(app_user_id);
  res.sendStatus(200);
});