Application Directory

By default, FastAPI Cloud expects your application at the root of your repository. But if your FastAPI app lives in a subdirectory, you can configure an application directory to tell FastAPI Cloud where to find it.

This is useful for monorepos, uv workspaces, and projects where the application code is nested inside the repository.

Setting the Application Directory

Using the Dashboard

1. Navigate to your App in the dashboard
2. Click Settings in the sidebar
3. In the Application Directory section, enter the relative path to your app directory (e.g., backend or packages/api)
4. Click Update

To reset back to the repository root, clear the field and click Update.

Path Rules

The directory must be a simple relative path. Here are the rules:

• Relative paths only — absolute paths like /app/backend are not allowed
• No path traversal — paths containing .. are rejected
• Allowed characters — letters, numbers, spaces, /, ., _, -

Valid Examples

Path	Description
backend	Single directory
packages/api	Nested directory
apps/web/python	Deeper nesting
my-app	Hyphens are fine
my_app	Underscores are fine

How It Affects Builds

When you set an application directory, FastAPI Cloud uses it during the build process:

1. Dependencies are installed from the specified directory.
2. Your app runs from that directory so relative imports and file paths resolve correctly.

Monorepo and Workspace Support

The application directory works with uv workspaces. If you have a uv.lock file at the root of your repository and your app is in a subdirectory, FastAPI Cloud will:

1. Resolve dependencies using the root uv.lock
2. Install dependencies for the workspace member in your app directory
3. Install any workspace members your app depends on