> ## Documentation Index
> Fetch the complete documentation index at: https://www.activepieces.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Variable Schema

A variable is an encrypted secret, credential, or other value stored once in a project. Any step in any flow of that project can reference it as `{{variables['NAME']}}`. See [Project Variables](https://www.activepieces.com/docs/flows/project-variables.md) for how flows use them.

> [!NOTE]
>
> Values are write-only for API keys. No response from these endpoints contains the value, and an API key cannot read it back. Revealing a value requires the session of a signed-in project member with write access (Editor or Admin).


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