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## In-call SMS and WhatsApp messaging

Voice agents can now send SMS or WhatsApp messages during a live call and feed the customer's reply back into the conversation as a variable. This is useful for capturing details that are hard to relay by voice — one-time passcodes, email addresses, invoice IDs, links, and short menus of options.

* Two new action types, `INCALL_SMS` and `INCALL_WHATSAPP`, attachable to a voice agent under the **During** phase.
* Blocking or non-blocking reply handling with a configurable timeout and fallback message.
* Replies are injected into the call transcript and exposed as `{sms_reply}` / `{whatsapp_reply}` variables.
* Requires a connected Twilio account; in-call WhatsApp additionally requires a linked WhatsApp sender.

See the [In-Call Messaging](/in-call-messaging) guide.

| Endpoint                                                                            | Change                                                   |
| :---------------------------------------------------------------------------------- | :------------------------------------------------------- |
| [**POST /actions**](/api-reference/platform-api/actions/create-action)              | Accepts `INCALL_SMS` and `INCALL_WHATSAPP` action types. |
| [**PUT /actions/\{action\_id}**](/api-reference/platform-api/actions/update-action) | Accepts `INCALL_SMS` and `INCALL_WHATSAPP` action types. |
| [**GET /actions/\{action\_id}**](/api-reference/platform-api/actions/get-action)    | `action_type` may be `INCALL_SMS` or `INCALL_WHATSAPP`.  |
| [**GET /actions**](/api-reference/platform-api/actions/list-action)                 | `action_type` may be `INCALL_SMS` or `INCALL_WHATSAPP`.  |