---
title: Configuration Options
description: Project settings, build paths, branches, and environment variables.
order: 2
---

Project settings control how Atlasflow builds and runs your application. Update them anytime from the project **Settings** pages in the dashboard.

## Build settings

| Setting             | Description                                              | Default                   |
| ------------------- | -------------------------------------------------------- | ------------------------- |
| **Root directory**  | Subdirectory within the repo containing your application | `/`                       |
| **Dockerfile path** | Path to your Dockerfile, relative to the root directory  | `Dockerfile`              |
| **Default branch**  | Branch that triggers production deployments on push      | Repository default branch |

If no Dockerfile is found at the configured path, Atlasflow auto-detects your stack and generates a build plan.

### Root directory

Use root directory when your application lives in a monorepo subdirectory. The path must start with `/`; use `/` when your app is at the repository root. See [Monorepos](/docs/guides/monorepos.md) for detailed layouts.

## Environment variables

Environment variables are scoped to either **build** (available during the image build) or **runtime** (injected into the running container). Values are encrypted at rest.

See [Environment variables](/docs/guides/environment-variables.md) for the full guide.

## Build machine tier

Choose how much compute each build receives. See [Build machines](/docs/guides/build-machines.md) for tier specs and plan availability.

Change the tier under **Settings → Build Machine**.

## GitHub connection

If repository access changes or the GitHub App installation is removed, reconnect GitHub from project settings. Atlasflow needs an active installation to clone your repository and receive push webhooks.

## Next steps

- [Environment variables](/docs/guides/environment-variables.md): build and runtime configuration.
- [Build machines](/docs/guides/build-machines.md): compare Standard, Enhanced, and Performance tiers.
- [Custom domains](/docs/networking/custom-domains.md): configure production hostnames.