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

# Variables & Secrets

> Reusable configuration and credentials for your flows and agents

**Variables** let you store configuration once and reuse it across flows and agents instead of hardcoding values. **Secrets** are variables whose value is write-only — you can set and reference them, but they're never shown again after saving, so API keys and tokens stay safe.

## Variables vs. secrets

|                    | Variable                                   | Secret                                         |
| ------------------ | ------------------------------------------ | ---------------------------------------------- |
| **Purpose**        | Non-sensitive config (URLs, IDs, defaults) | Sensitive values (API keys, tokens, passwords) |
| **Readable back?** | Yes                                        | No — write-only; the value is redacted on read |
| **Typical use**    | Environment/config a flow reads            | Credentials a node or integration needs        |

Values are **typed** — `string`, `number`, `boolean`, `json`, `datetime`, or `file` — so a flow gets the right shape when it reads one.

## Scopes

* **Workspace variables** — shared across everything in a workspace. Manage them in workspace settings.
* **Workflow variables** — scoped to a single flow, for values that only that flow needs.

## Using them

<CardGroup cols={2}>
  <Card title="In flows" icon="workflow">
    Reference a variable from a node's config instead of typing a literal, so one change updates every flow that uses it.
  </Card>

  <Card title="For credentials" icon="key">
    Store an API key as a **secret**, then reference it where a node or integration needs it — the value never appears in the flow definition.
  </Card>

  <Card title="Programmatically" icon="code">
    List, create, update, and delete variables via the [SDK](/sdk/resources/admin) and [REST API](/api-reference/v1--variables/list-variables). Secret values are stripped from responses.
  </Card>
</CardGroup>

<Warning>
  Because secret values can't be read back, keep the source of truth for a
  credential wherever you generated it. To rotate, set a new value on the secret.
</Warning>