***

## title: WhatsApp

WhatsApp outbound is useful when users prefer to receive business calls in WhatsApp instead of PSTN.

## Setup flow

1. Connect and verify your WhatsApp Business number in Voximplant.
2. Prepare an outbound scenario started via routing-rule run or API.
3. Pass target WhatsApp user number and business caller ID in custom data.
4. Place the call with `VoxEngine.callWhatsappUser(...)`.
5. After `CallEvents.Connected`, create and bridge your Voice AI connector.

```js title="WhatsApp outbound leg"
const call = VoxEngine.callWhatsappUser({ number: destination, callerid: callerId });
```

## Channel constraints to plan for

* WhatsApp calling has channel-specific policy, availability, and account requirements.
* Keep WhatsApp and PSTN legs in separate scenarios; do not mix PSTN and WhatsApp legs in one scenario.
* Validate target countries and business-initiated call policy before launch.

## Voice AI notes

* Keep first-turn prompts short and explicit.
* Use channel-aware fallback logic (for example retry on PSTN in a separate flow).
* Track WhatsApp-specific failures separately from PSTN failures in logs.

## Links

* WhatsApp calls guide: [https://voximplant.com/docs/guides/integrations/whatsapp-calls](https://voximplant.com/docs/guides/integrations/whatsapp-calls)
* WhatsApp outbound API (`callWhatsappUser`): [https://voximplant.com/docs/references/voxengine/voxengine/callwhatsappuser](https://voximplant.com/docs/references/voxengine/voxengine/callwhatsappuser)

<Info title="Screenshots/graphics needed">
  - WhatsApp business number connected to application.
  - Outbound WhatsApp scenario run with custom data.
  - New graphic: WhatsApp-only outbound flow with PSTN fallback in a separate scenario.
</Info>