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

# Variables

> Create and reference reusable Tracecat workspace variables in workflows and agents: share configuration and constants across automations without duplicating values.

## Overview

Variables store reusable non-secret values.

## Using variables in expressions

Access a variable in expressions with:

```yaml theme={null}
${{ VARS.<variable_name>.<key> }}
```

## Variable fields

Each variable has these fields:

* Name: a lowercase snake case name such as `jira` or `api_config`
* Values: one or more key-value pairs
* Environment: the Workflow environment where the variable applies

## When to use variables

Use variables for non-sensitive values such as:

* Base URLs
* Project IDs
* Queue names
* Routing rules
* Tenant-specific defaults

Use a [secret](/automations/core-concepts/secrets) for sensitive values.

## Variable environments

Every variable belongs to a Workflow environment.

* Default source: the workflow default environment in [Workflows](/automations/workflows).
* Override: per action in [Actions](/automations/actions) control flow.
* Fallback: `default`.

## Access variables in agents

Agents can use variable expressions in tool arguments and integration configuration. Values are resolved during tool execution and are not fetched directly by the LLM provider.

<CodeGroup>
  ```text theme={null}
  When you call Jira tools, use `${{ VARS.jira.base_url }}` as the base URL and `${{ VARS.jira.project_key }}` as the default project key.
  ```
</CodeGroup>

## Related pages

* See [Secrets](/automations/core-concepts/secrets) for sensitive values such as API keys, passwords, and certificates.
* See [Expressions](/automations/core-concepts/expressions) for how expressions work across triggers, actions, secrets, and variables.