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

# Environment variables

> What environment variables are and how to use them across your configurations.

Environment Variables allow you to store sensitive or reusable values, such as API keys, passwords, and tokens, centrally in Alumio. Instead of hardcoding credentials directly into connection or transformer configurations, you reference an environment variable by name. This keeps sensitive data out of your configurations and makes it easier to update a value in one place without touching every integration that uses it.

Navigate to **More → System → Environment Variables** to create and manage environment variables.

### What Environment Variables can do

* Store sensitive values such as API keys, passwords, and tokens securely in one place.
* Reference stored values across any configuration using `${VARIABLE_NAME}` syntax.
* Encrypt values so they are hidden in logs and never exposed in plain text.
* Update a credential once and have the change apply everywhere it is referenced.

### Filtering Environment Variables

The overview page lists all environment variables in your environment. Each row shows the variable name, an optional description, the value (masked if encrypted), and whether encryption is enabled. Filters are available for Name and Description. Use **+ Add Filter** for additional conditions. Click any column header to sort.

### Creating an Environment Variable

An environment variable has three fields:

| Field     | Required | Description                                                                                    |
| :-------- | :------- | :--------------------------------------------------------------------------------------------- |
| Name      | Yes      | The variable name used to reference it in configurations (e.g. `${AWS_ACCESS_KEY}`).           |
| Value     | Yes      | The value to store, for example, an API key or password.                                       |
| Encrypted | No       | When enabled, the value is encrypted and hidden in logs. Recommended for all sensitive values. |

### Using Environment Variables in configurations

Once created, an environment variable can be referenced anywhere in Alumio that accepts plain text input: connection settings, transformer fields, HTTP headers, and more, using the `${VARIABLE_NAME}` syntax. The platform resolves the variable at runtime and substitutes the stored value automatically.