WhatsApp Business API (Cloud API)

The WhatsApp Business app is a mobile app for small businesses: one phone, a few devices, manual replies. The WhatsApp Business Platform is for software: messages arrive through webhooks and are sent through an API, so they can be handled by a team inbox, automated workflows or an AI assistant, on any volume.

Meta now offers the platform as the Cloud API, hosted on its own infrastructure. The older On-Premises API, which businesses ran themselves, was sunset in October 2025. Businesses usually connect through a solution provider or a platform that integrates Meta's Embedded Signup, which handles the account and phone-number setup.

When a customer messages a business, a 24-hour customer service window opens, and it resets with each new customer message. Within that window the business can reply freely. Outside it, the business can only send pre-approved message templates. Templates fall into categories — marketing, utility, authentication — and service replies are those sent within the window.

Meta charges per delivered message, at rates that depend on the message category and the recipient's country. Since 1 October 2026, service replies — including those written by an AI assistant — are charged once a phone number has used its free tier of 1,000 service messages in the month, and utility templates sent inside an open window are charged as well. Conversations started from a click-to-WhatsApp ad open a free entry-point window. Rates and rules change often, so check Meta's pricing page before budgeting.

Businesses that already use the WhatsApp Business app can, through Embedded Signup, keep using the app on their phone while connecting the same number to the Cloud API — a mode Meta calls coexistence. Otherwise, a number registered on the API can no longer be used in the app.

Other points to plan for: business verification affects throughput and the official business account badge; customers send voice notes, images and locations, not only text; and opt-in is required before sending marketing templates.

AI SmartTalk connects a WhatsApp number to an assistant through Meta's Embedded Signup, including coexistence for numbers already used in the WhatsApp Business app. The assistant answers WhatsApp messages from the same knowledge and catalog as on the website, transcribes customers' voice notes, and hands conversations to the shared inbox when a person is needed. Message templates can be managed from the AI SmartTalk admin.