›Is this the official WhatsApp Business API?
No. It links a regular WhatsApp or WhatsApp Business app number as a companion device (like WhatsApp Web) and exposes it as an API. No Meta verification, templates or per-conversation fees — and it is subject to WhatsApp's linked-device terms rather than the Cloud API's.
›Does the phone need to stay online?
No. WhatsApp multi-device keeps linked devices working for weeks without the phone. The phone must come online occasionally (WhatsApp unlinks devices that have not seen the phone for a long time).
›Can I use one number from several systems?
Yes — one session, many callers. Attach metaData to each send so the echo on your webhook (and hosted history) tells you which system sent it.
›Why is `to` a LID and not a phone number?
WhatsApp addresses users by an internal linked id. Inbound events give you the sender's LID; when sending you can still pass +phone and we resolve it. See Core concepts.
›Do you store my messages?
Only if you enable the hosted inbox (/set-org-id + hosted webhook). Otherwise the platform relays and stores nothing but the session itself.
›What happens when your servers restart?
Every paired session reconnects automatically within seconds; webhook and workspace settings persist. You do not need to call /start again.
›How do I hand a number to a customer of mine?
Create the session under a clientId for them, then POST /set-api-secret to give them a secret that works for that one session only.
›Can I receive messages without a public server?
Not directly — webhooks need a reachable HTTPS URL. Use a tunnel during development, or enable the hosted inbox and poll GET /chatrooms instead.
›Are polls, buttons and reactions supported?
Yes, both directions. Buttons render as native flows on current WhatsApp versions; keep a typed-reply fallback for older clients.
›What about WhatsApp channels, status and broadcast lists?
Not delivered and not sendable. Groups are supported on an opt-in basis.