How to Integrate an OTP API into a Reseller Website
A stable OTP reseller website is not only about creating orders. The system must display catalog data, calculate prices, create orders, wait for OTP, handle cancellation, process refunds, and keep API keys secure. Poor design can lead to double charge, stuck orders, unsynchronized prices, or confused users.
This guide explains a practical OTP API integration pattern for reseller websites. The focus is not a specific programming language, but the correct flow that keeps your system safer and easier to maintain.
Main components
- Service and country catalog page.
- Pricing and markup engine.
- Backend create-order endpoint.
- Worker or cron for status polling.
- Cancellation and refund flow.
- User order history.
- Audit logs for debugging.
Never call the OTP API directly from the user browser. Your API key must stay on the reseller server, not inside frontend JavaScript.
Catalog and pricing flow
Fetch service lists from the API or cache them periodically in your own database. Caching keeps pages fast and reduces repeated requests. For pricing, store the public reseller price that already includes your markup. Do not expose internal details that users do not need.
If the API supports operator or server selection, show it as an optional control while keeping a sensible default. Existing users who do not choose an operator should still be able to order if the flow supports automatic selection.
Create order flow
When a user buys a number, the reseller backend should check balance, validate service/country/server, generate an idempotency key, call the create-order API, store the local order, and subtract reseller balance. Do not charge the user twice if they refresh or retry.
Use an idempotency key for each intended order. If a request times out, the backend can recover the previous result instead of accidentally creating a new order.
Polling OTP and order status
After an order is created, do not force users to refresh manually. Use backend polling or a worker. Common statuses include pending, OTP received, success, cancelled, expired, and failed. Display them in simple language so users know whether to wait or take action.
Cancellation and refunds
Cancellation must be idempotent. If a user clicks cancel twice, the system must not refund twice. Store a guard key or local settlement state so one order can only have one refund settlement. After successful cancellation, update local order status and user balance log.
API key security
- Store API keys in environment variables or a secret manager.
- Never send API keys to frontend code.
- Limit who can view or rotate keys.
- Rotate keys when you suspect exposure.
- Log requests without printing the full key.
Common reseller mistakes
Common mistakes include creating orders from frontend code, not storing idempotency keys, having no polling worker, assuming every cancel means full refund, and keeping no audit logs. Another mistake is deleting failed local orders, even though they are important for debugging and user support.
Production checklist
- User balance cannot go negative unless your business rules allow it.
- Retry does not create double charge.
- Double cancel does not create double refund.
- API key never appears in HTML, JavaScript, or public responses.
- Every balance change has a balance log.
- Workers can continue after server restart.
FAQ
Does a reseller need a local database?
Yes, strongly recommended. Without a local database, tracking orders, balances, refunds, and support cases becomes difficult.
Polling or webhook?
Webhook is good when available and reliable. Polling is still useful as a fallback so status updates do not depend on a single mechanism.
Should operator selection be required?
It depends on the API flow. If operator is optional, design the UI to support both users who choose an operator and users who rely on automatic default selection.
With OTPZap API, resellers can build a cleaner OTP purchase flow where catalog, order creation, status, cancellation, and refund handling are managed from their own backend without exposing internal details to end users.