# Use variables in your actions
URL: https://docs.awellhealth.com/docs/design-care-flows/use-variables-in-your-actions

> For the complete documentation index, see [llms.txt](https://docs.awellhealth.com/llms.txt).



A **variable** puts data from the care flow into the content it sends, so one message becomes personal to
each patient without being written twice.

Variables work in messages, clinical notes, API calls, and other action fields.

## Variables are used for personalization, reports and API calls [#variables-are-used-for-personalization-reports-and-api-calls]

* **Personalizing a message**, such as addressing a patient by first name.
* **Building a clinical report**, such as listing a patient's answers or a score.
* **Fine-tuning an API call**, such as passing an identifier or a reference date.

## Insert a variable with the slash command [#insert-a-variable-with-the-slash-command]

Typing `/` in an action input field offers the existing variables and the option to create a new one.
Each care flow also has a dedicated data variables section.

## Dynamic variables change per patient and constants don't [#dynamic-variables-change-per-patient-and-constants-dont]

* **Dynamic** variables hold data gathered during the care flow: baseline data, form answers, API
  responses. The value differs per patient.
* **Constant** variables hold static data, the same for everyone.

Use a constant when the same value appears in several actions, so changing it in one place changes it
everywhere.

## An empty variable renders as nothing [#an-empty-variable-renders-as-nothing]

If a message depends on an answer the patient hasn't given yet, they get a sentence with a gap in it.
Check the order of the steps as well as the wording.

## Next steps [#next-steps]

**Next:** [Clinical note](/docs/design-care-flows/clinical-note), which relies heavily on variables.