WhatsApp API and automation glossary

Terms

WhatsApp Business API

Meta's official API for businesses, accessed through a Business Solution Provider (BSP). It requires business verification, the use of approved templates for proactive messages, and charges per conversation/message. It's built for enterprise volumes and for those who need Meta's formal compliance. It shouldn't be confused with unofficial APIs that link a personal number.

Baileys

An open-source library that connects to the WhatsApp Web protocol using a personal number, without going through the official Business API. It's the technical base of many unofficial WhatsApp APIs (Whaiz included). Upsides: no Meta approval and no per-message fees. To be honest: using a personal number via an unofficial library carries a risk of restrictions from Meta that no one fully removes.

Personal number (vs business number)

A personal WhatsApp number is the one you normally use in the app, linked via QR as with WhatsApp Web. Unofficial APIs automate this number. The business number of the official Business API, instead, is registered with Meta through a BSP and follows different rules, templates and costs.

QR linking

The method used to link a personal number to a service: you scan a QR code from the WhatsApp app, exactly like WhatsApp Web. The session stays active as long as the phone is reachable; it has to be reconnected periodically. It doesn't require sharing your password or PIN.

Anti-ban

The set of measures to reduce the risk of WhatsApp limiting an automated number: typically a queue that spaces out sends with a minimum delay and a random variation (jitter), so it doesn't look like a spammer. It's a best-effort mitigation, not a guarantee: no anti-ban fully removes the risk of restrictions.

24-hour session (window)

In the context of the official Business API, it's the 24-hour window from the user's last message within which the business can reply with free-form messages; outside that window, approved paid templates are required. It's a concept specific to the official API and helps explain why that model has different costs and constraints than automating a personal number.

Catch-all

A mode where the bot also replies automatically to contacts that don't have a dedicated configuration, applying a default behavior. Useful for business numbers that want a universal auto-reply without having to set up every single chat.

Webhook

An HTTP callback the service sends to your server when an event happens, for example a new incoming message. It lets your software react in real time (receive, process, reply) without having to constantly poll the API.

BSP (Business Solution Provider)

A Meta-authorized partner that provides access to the official WhatsApp Business API (for example Twilio). It handles business verification, templates and per-conversation billing. It's a necessary actor in the official API world, not in that of unofficial APIs on a personal number.

Meta templates (HSM)

Messages pre-approved by Meta, required in the official Business API to message a user outside the 24-hour window. They have a cost and must follow format and category rules. APIs on a personal number don't use templates, because they work like a normal WhatsApp chat.

Frequently asked questions

Resources