> ## Documentation Index
> Fetch the complete documentation index at: https://developer.fexpayments.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Quick-Start Checklist

> Pre-launch checklist for FEX merchant integrations.

Work through this list in order before going live.

**Credentials & Setup**

* Received `merchant_id`, `client_id`, and `client_secret` from platform admin
* Stored `client_secret` in a secrets manager (not in source code or environment variables)
* Tested token generation via the client credentials flow

**Terminal Registration**

* Created at least one counter (POS terminal) via `POST /merchant/api/v1/counters`
* Saved the counter's `webhook_secret` in your secrets manager

**Backend Integration**

* Implemented token refresh logic (refresh at least 30 s before expiry)
* Implemented webhook endpoint with HMAC-SHA256 signature verification
* Implemented retry/backoff logic for `5xx` responses

**End-to-End Testing**

* Tested Standard QR flow end-to-end in sandbox
* Tested Reverse QR flow end-to-end in sandbox
* Verified webhook delivery and signature validation

**Go Live**

* Contact platform admin to activate your live environment

***

*For sandbox access, base URLs, or credential issues, contact your platform administrator.*