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

# Decision Control Tower Sidecar — Configuration

> Environment-variable reference for the Decision Control Tower Sidecar — database, callbacks, and optional integrations.

The Sidecar is configured entirely through environment variables. This chapter is the reference; for how to run it, see [Deployment](/docs/decision-control-tower-sidecar/deployment/overview).

## Core

| Variable                 | Default     | Description                                    |
| ------------------------ | ----------- | ---------------------------------------------- |
| `APP_HOST`               | `localhost` | Bind address. Set to `0.0.0.0` in a container. |
| `BACKEND_PORT`           | `8080`      | HTTP port the Sidecar listens on.              |
| `SPRING_PROFILES_ACTIVE` | `prod`      | Active configuration profile.                  |

## Database

The Sidecar requires its **own** PostgreSQL database — never share a schema with Tower.

| Variable                              | Default    | Description                                                                      |
| ------------------------------------- | ---------- | -------------------------------------------------------------------------------- |
| `ALETYX_DC_TOWER_SIDECAR_DB_URL`      | (required) | JDBC URL, e.g. `jdbc:postgresql://sidecar-postgres:5432/decision_tower_sidecar`. |
| `ALETYX_DC_TOWER_SIDECAR_DB_USERNAME` | (required) | Database user.                                                                   |
| `ALETYX_DC_TOWER_SIDECAR_DB_PASSWORD` | (required) | Database password. Source from a secret manager.                                 |

## Tower callbacks

How the Sidecar reaches Tower Core. The secret must match the value configured on Tower.

| Variable                                     | Default    | Description                                                                                                        |
| -------------------------------------------- | ---------- | ------------------------------------------------------------------------------------------------------------------ |
| `ALETYX_DC_TOWER_SIDECAR_TOWER_CALLBACK_URL` | (required) | Base URL of Tower Core, e.g. `http://decision-control-tower:8080`.                                                 |
| `ALETYX_OIDC_CALLBACK_SECRET`                | (empty)    | Shared secret authenticating Sidecar → Tower callbacks. **Must match Tower.** Rotate on both sides simultaneously. |

## Integrations (optional)

These variables configure the example actions. An action only runs if the **workflow includes it** — there is no single "integrations" switch. Git push additionally has its own master switch (`…GITHUB_ENABLED`, default `false`); Slack has no enable flag and simply stays inactive until a token and channel are set. With the shipped defaults, an approved promotion performs no outbound Git or messaging calls.

<Warning>
  **Never ship credentials in the image**

  Provide tokens **only** through environment variables / your secret manager. Do not bake them into configuration files or images — a token committed to a repository will be detected and revoked.
</Warning>

### Git versioning

Commits the promoted model's files to a Git repository on approval. See [Git Model Versioning](/docs/decision-control-tower-sidecar/how-to/git-model-versioning).

| Variable                                         | Default                  | Description                                                                   |
| ------------------------------------------------ | ------------------------ | ----------------------------------------------------------------------------- |
| `ALETYX_DC_TOWER_SIDECAR_GITHUB_ENABLED`         | `false`                  | Master switch. When `false`, the Git step is a no-op and no model is fetched. |
| `ALETYX_DC_TOWER_SIDECAR_GITHUB_API_URL`         | `https://api.github.com` | Git host API base URL.                                                        |
| `ALETYX_DC_TOWER_SIDECAR_GITHUB_TOKEN`           | (empty)                  | Access token with **Contents: read and write** on the target repository.      |
| `ALETYX_DC_TOWER_SIDECAR_GITHUB_REPO`            | (empty)                  | Target repository in `owner/repo` form.                                       |
| `ALETYX_DC_TOWER_SIDECAR_GITHUB_BRANCH`          | `main`                   | Branch to commit to.                                                          |
| `ALETYX_DC_TOWER_SIDECAR_GITHUB_COMMITTER_NAME`  | `Aletyx Tower`           | Commit author/committer name.                                                 |
| `ALETYX_DC_TOWER_SIDECAR_GITHUB_COMMITTER_EMAIL` | `tower@aletyx.ai`        | Commit author/committer email.                                                |

### Messaging (Slack)

Posts a message when a promotion completes.

| Variable                                | Default                 | Description                                  |
| --------------------------------------- | ----------------------- | -------------------------------------------- |
| `ALETYX_DC_TOWER_SIDECAR_SLACK_API_URL` | `https://slack.com/api` | Messaging API base URL.                      |
| `ALETYX_DC_TOWER_SIDECAR_SLACK_TOKEN`   | (empty)                 | Bot token. Blank disables messaging.         |
| `ALETYX_DC_TOWER_SIDECAR_SLACK_CHANNEL` | (empty)                 | Target channel ID. Blank disables messaging. |

### REST callout

| Variable                                   | Default                 | Description                                                                    |
| ------------------------------------------ | ----------------------- | ------------------------------------------------------------------------------ |
| `ALETYX_DC_TOWER_SIDECAR_HOLIDAYS_API_URL` | `https://date.nager.at` | Base URL for the example public-REST callout used by the integration workflow. |

## Next Steps

* [Git Model Versioning](/docs/decision-control-tower-sidecar/how-to/git-model-versioning): enable and use the Git integration
* [Architecture](/docs/decision-control-tower-sidecar/architecture): how these pieces fit together