---
id: environment-variables
title: Environment variables
sidebar_label: Environment variables
---

Everything the control plane reads from the environment, and what happens when
it is absent.

## Server

| Name                       | Required        | Default                     | Notes                                                                                                                                                              |
| -------------------------- | --------------- | --------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `GRPC_HOST`                | **yes**         |                             | The `host:port` agents dial. Boot fails without it. There is deliberately no fallback to the web host: that would hand every agent a port that does not speak gRPC |
| `MONGO_URI`                | no              | `mongodb://localhost:27017` | The database name is taken from the URI path, falling back to `vantage`. There is no separate `MONGO_DB`                                                           |
| `REDIS_ADDR`               | no              | `localhost:6379`            | Sessions only                                                                                                                                                      |
| `REDIS_USERNAME`           | no              |                             | Redis 6+ ACL user. Leave empty against a legacy `requirepass` instance, which authenticates with the password alone                                                |
| `REDIS_PASSWORD`           | no              |                             | Leave empty for an unauthenticated Redis. Both of these exist so an install can use a managed Redis rather than the bundled one                                    |
| `KEY_ENCRYPTION_KEY`       | yes in practice |                             | 64 hex characters (32 bytes) for AES-256-GCM. Required for private keys, vault secrets, OIDC client secrets and console credentials                                |
| `GITEA_HOST`               | yes             | `gitea.example.com`         | Used to build the install scripts and agent download URLs. The default is a placeholder that will not resolve                                                      |
| `GUACD_ADDR`               | no              | `guacd:4822`                | The [browser console](../vantage/browser-console.md) daemon                                                                                                        |
| `PROXY_ADVERTISE_HOST`     | no              | `server`                    | The hostname **guacd** uses to reach the control plane's console relay. Wrong here and every console session fails at connect with guacd unable to resolve the relay |
| `PROXY_LISTEN_HOST`        | no              | `0.0.0.0`                   | Interface the ephemeral relay listeners bind. Narrow it only if guacd shares a known interface                                                                     |
| `APP_ROOT_LABEL`           | no              | `vantage`                   | The app root label for the host and session organisation guard                                                                                                     |
| `VANTAGE_WORKFLOW_LOG_DIR` | no              |                             | Where workflow run logs are written                                                                                                                                |

:::danger `KEY_ENCRYPTION_KEY` has no recovery path
It encrypts SSH private keys, vault secrets, OIDC client secrets and console
credentials. Lose it and all of them are unreadable. Back it up separately from
the database it protects.
:::

:::info A wrong `APP_ROOT_LABEL` fails quietly
It does not error. It simply stops matching, and the host/session guard stops
protecting anything.
:::

### Not configurable

The HTTP port (`8080`) and the gRPC port (`9090`) are fixed in the server. The
`HTTP_PORT` and `GRPC_PORT` entries in the shipped Compose file are inert —
remap with Docker's port publishing instead.

## Agent

The agent reads no environment variables. Everything is in its
[config file](./agent-config.md).