Verify Payments

After a customer completes a payment, you must verify the result on your server before fulfilling the order. The redirect back to your app is not proof of payment — it can be triggered by anyone who knows your callback URL. Always verify server-side.

Seev gives you two ways to verify a payment: callback verification (at redirect time) and transaction lookup (at any time using a reference or transaction ID).

Method 1: Callback verification

When Seev redirects the customer back to your redirectUrl, it appends a session_id query parameter. Call Seev.callback() in that route handler to verify the session and get the payment result.

// GET /payment/callback?session_id=checkout_abc123
import Seev from '@seev/sdk';

export async function GET(req: Request) {
  const session = await Seev.callback();
  // or pass the session ID explicitly:
  // const session = await Seev.callback('checkout_abc123');

  if (session.isSuccessful()) {
    // Payment confirmed — safe to fulfil
    await db.orders.update({
      ref: session.reference,
      status: 'paid',
    });
    return Response.redirect('/order/confirmed');
  } else {
    // Payment failed, cancelled, or pending
    return Response.redirect(`/order/failed?status=${session.status}`);
  }
}

Callback session object

Method 2: Transaction lookup

Use Seev.transaction() to fetch the status of any transaction at any time using its reference or ID. This is useful for:

• Verifying payments that came through webhooks
• Checking the status of a payment initiated elsewhere
• Building an order status page that polls for updates

const transaction = await Seev.transaction('txn_abc123xyz');

console.log(transaction.id);
console.log(transaction.status);    // 'completed' | 'pending' | 'failed'
console.log(transaction.amount);    // in smallest currency unit
console.log(transaction.currency);
console.log(transaction.reference);

Transaction statuses

Method 3: Webhooks (recommended for fulfilment)

For fulfilment workflows, webhooks are more reliable than callback verification alone. Seev sends a checkout.completed event to your webhook endpoint as soon as a payment is confirmed — even if the customer closes the browser before being redirected.

Use Seev.callback() to give the customer immediate feedback in the UI, and use the checkout.completed webhook to trigger your fulfilment logic.

// Webhook handler — POST /webhooks/seev
const event = await Seev.webhook(req.body, req.headers['x-seev-signature']);

if (event.is('checkout.completed')) {
  const data = event.getData();
  await fulfillOrder(data.reference);
}

See the Webhooks guide for setup, delivery logs, retries, and signature verification.

Which method should I use?

Using both Seev.callback() and webhooks together is the most robust pattern — the callback handles the UI, and the webhook handles fulfilment independently.