--- name: paystack-inline-server-verify description: Use when pairing Paystack Inline checkout with backend transaction initialization and server-side verification for secure Paystack transactions. license: MIT compatibility: "Modern browsers with Paystack Popup; package tooling/SSR builds require Node.js >=22.0.0; ESM package; client-side checkout with server verification." --- # Paystack Inline Server Initialize and Verify The safest Inline flow initializes the transaction on your backend, sends `access_code` to the browser, and verifies the transaction on the backend after checkout succeeds. ## Backend initialization Use a server SDK or direct Paystack API call with your secret key. ```ts async function initializePayment() { const result = await paystack.transaction_initialize({ body: { email: customer.email, amount: 500000, reference: payment.reference, }, }); const initialized = result.unwrap(); return { accessCode: initialized.access_code }; } ``` ## Frontend resume ```ts const PaystackPop = await loadPaystack(); const popup = new PaystackPop(); popup.resumeTransaction(accessCode, { onSuccess: ({ reference }) => verifyOnServer(reference), }); ``` ## Backend verification After success, call transaction verify on the backend before fulfilling value. ```ts const verified = await paystack.transaction_verify({ params: { path: { reference } }, }); const data = verified.unwrap(); ``` ## Best practices - Never deliver value based only on `onSuccess`. - Store your own payment attempt before initializing Paystack. - Compare amount, currency, reference, and customer before fulfillment. - Make verification and fulfillment idempotent.