> For a complete page index, fetch https://docs.synthflow.ai/llms.txt. For full documentation content, fetch https://docs.synthflow.ai/llms-full.txt.

# Variables on SMS, real-time booking, and call transfers

> Send SMS, real-time booking, and call transfer actions now support variables, like Custom Actions.

Send SMS, real-time booking, and call transfers now support variables the same way as Custom Actions, so one value from the caller can flow through those actions without duplicating it.

![](https://storage.googleapis.com/granular-changelog/doc-images/action-variables-picker.png)

[Learn more about variables on actions](/variables#action-placeholders-and-mapping).