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

# Linux environment variables

To [create a Core Instance](/ingest/pipeline/v2/install/create-instance) on Linux, you
must configure the following environment variables. Chronosphere provides these
environment variables as part of the systemd service, using the
`/opt/calyptia/etc/calyptia-custom.conf` file.

| Name                                 | Description                                                                                                                                                         |
| ------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `CALYPTIA_CLOUD_PROJECT_TOKEN`       | The token used to manage the Core Instance.                                                                                                                         |
| `CALYPTIA_CORE_INSTANCE_NAME`        | Optional: Sets a specific name, otherwise selects a random name.                                                                                                    |
| `CALYPTIA_CORE_INSTANCE_NAME_PREFIX` | Optional: The prefix to use for a randomly generated Core Instance name.                                                                                            |
| `CALYPTIA_CLOUD_URL`                 | The URL of the Telemetry Pipeline backend. Default: `cloud-api.calyptia.com`.                                                                                       |
| `CALYPTIA_CORE_ADDITIONAL_FLAGS`     | Optional: Custom flags to assign to the Core Instance. These arguments are passed to [Pipeline CLI](/ingest/pipeline/pipeline-cli) when creating the Core Instance. |