Technical limits
| Item | Limit |
|---|---|
| Request timeout | 15 s for sends; media fetch up to 60 s |
| Media | 100 MB fetch cap; files over 60 MB fall back to a link; uploads ≤ 128 MB (keep ≤ 64 MB) |
| History | /chatrooms/{id}/messages returns the last 200 messages |
| Webhook delivery | 4 attempts with backoff, 15 s response window, then dropped |
| Poll lookup | 8 s response window |
| Group subject | 25 characters (WhatsApp) |
| Edits | Own text messages, ~15 minutes after sending (WhatsApp) |
| App-level rate limiting | None — you are responsible for pacing |
WhatsApp's rules
This is a linked-device connection, not the Business API
Numbers can be temporarily or permanently banned by WhatsApp for behaviour that looks automated or unsolicited. Bans are applied by WhatsApp to the number; the API cannot lift them and we cannot guarantee delivery to a banned number.
Behaviour known to trigger enforcement:
- Messaging people who have not messaged you first or saved your number, especially in volume.
- Identical text to many recipients in a short window; sending faster than a person could type.
- Bulk "is this number on WhatsApp" checks against lists.
- Adding people to groups without consent.
- High block/report rates from recipients.
Staying in good standing
- Warm up new numbers: low volume, replies before outreach, a real profile photo and name.
- Pace outbound: a few messages a minute per number, randomised delays,
/send-typingbefore replies. - Personalise content; vary templates; respect opt-outs immediately.
- Prefer inbound-led flows: reply to leads, confirmations, reminders people asked for.
- Watch
/health/clientsforbannedand stop the pipeline that caused it.
Accounts used for spam or abuse are suspended from the service.