Integrations
Fexl Lite is built to do most retail jobs in one app — but a real shop has hardware around it (printers, card terminals, drawers) and external channels around that (Telegram for owner alerts, WhatsApp for customers). This section is the four integrations the desktop and cloud builds know about, with their full setup walkthroughs and the troubleshooting trees that follow.
What’s here
ESC/POS receipt printers
USB, network, and OS-default printing through ESC/POS. Path patterns, code pages, the discovery flow, and the symptom-to-fix tree.
Nebula payment terminal
Pair USB / Wi-Fi / cloud-routed Nebula terminals. The transaction polling loop, refund-from-terminal, and the connection-failure tree.
Telegram notifications
Two-minute bot setup via @BotFather. Channel ID discovery, per-event subscriptions, message format.
WhatsApp alerts
WhatsApp Business Cloud API onboarding. Template approval, the per-conversation pricing math, and quota planning.
Where each integration plugs in
Hardware integrations (printers, terminals) configure on device-scoped settings tabs — the choice is per-desktop, not per-tenant. Two tablets in the same shop with two different printers store two different paths in the same tenant document, both correct. Cloud sync deliberately ignores device-scoped fields.
Messaging integrations (Telegram, WhatsApp) configure on tenant-scoped settings tabs — one bot, one phone-number, one set of subscriptions for the whole shop. They live on Settings → Notifications.