WhatsApp Launches Calling API for Businesses: Inbound Calls Free, AI Agents Ready

What happened

Meta has rolled out the WhatsApp Business Calling API, giving businesses full programmatic control over phone calls on WhatsApp. The documentation now covers business-initiated calls, user-initiated calls, call recording, and call transcription.

The important part for small businesses: a customer who calls your WhatsApp number can be answered automatically by software. No human needed on the other end — an AI agent can pick up, answer questions, take bookings, and confirm orders.

How the pricing works

• User-initiated calls (customers calling you): FREE — no per-minute charge.
• Business-initiated calls (you calling customers): paid per minute, billed in 6-second increments, with volume-tiered pricing by country.
• Call transcription and recording: currently free on both call types.
• Outbound calling requires a valid payment method on the account.

What this means for AI voice agents

Until now, building an AI receptionist meant routing through telephony providers. With the Calling API, a business's own WhatsApp number becomes the phone line. The flow works via WebRTC: the call arrives as an SDP offer, your server accepts it, and audio streams straight to your AI stack (speech-to-text, LLM, text-to-speech).

This is the missing piece for AI receptionist services on WhatsApp: inbound calls cost nothing, and the bot runs on your existing infrastructure.

What's still required

• The business phone number must be registered on the WhatsApp Business Platform (Cloud API).
• The calls webhook must be subscribed and the Calling API enabled on the number.
• App Review is needed for the WhatsApp Business management and messaging permissions.
• Callers must grant call permission for business-initiated calls.

Takeaway: inbound WhatsApp calls are now free and automatable — the cheapest possible phone line an AI agent can answer.

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