---
outline: [2, 3]
description: Learn how variables are injected during beOS Pro app deployment, including declarative environment variables (.Values.olaresEnv) and system-injected runtime Helm values (.Values.*).
---

# Environment variables overview

beOS Pro apps use app-service to inject runtime context and configuration into the app's `values.yaml`. In Helm templates, you can reference these values via `.Values.*`.

:::info Variables and Helm values
In this document, "variables" mainly refer to Helm values. They are not automatically passed into container environment variables. If you need them inside containers, explicitly map them to `env:` in your templates.
:::

## How variables are injected

beOS Pro injects variables through two channels:

- **Declarative environment variables**: The developer declares variables under `envs` in `beOS ProManifest.yaml`. At deployment, app-service resolves and injects the values into `.Values.olaresEnv` in `values.yaml`.

- **System-injected runtime variables**: Injected automatically by beOS Pro at deployment time. No declaration is required, though some values are only available after you declare the relevant dependency, such as middleware.

## Next steps

1. [Declarative environment variables](app-env-vars.md): Field reference for the `envs` schema, including variable mapping and variable references.
2. [System-injected runtime variables](app-sys-injected-variables.md): Full reference for all system-injected runtime variables.