FastAPI Scalekit Authentication Example

A simple FastAPI app that shows how to add secure sign-in with Scalekit (OIDC). You can use it as a starting point or as a reference to integrate enterprise-grade authentication.

What this example includes:

• The app signs users in with Scalekit using the OpenID Connect (OIDC) authorization flow.
• The /dashboard page is protected and redirects unauthenticated users to the login flow.
• The configuration shows how to register an OAuth 2.0 client and wire login, callback, and logout endpoints.
• The templates use Bootstrap classes so pages render well on desktop and mobile.
• After login, the dashboard displays selected ID token claims to demonstrate how to access user information.

Prerequisites

• Python 3.8 or later is installed.
• pip is installed.
• You have a Scalekit account with an OIDC application. Sign up

🛠️ Quick start

Configure Scalekit

Pick one method below.

Method A — .env file (recommended for local dev):

Create or update .env in the project root:

# Replace placeholders with your values
SCALEKIT_ENV_URL=https://your-env.scalekit.io
SCALEKIT_CLIENT_ID=YOUR_CLIENT_ID
SCALEKIT_CLIENT_SECRET=YOUR_CLIENT_SECRET
SCALEKIT_REDIRECT_URI=http://localhost:8000/auth/callback

# Optional server config
DEBUG=True
SECRET_KEY=your-secret-key-change-me-in-production

Method B — environment variables:

export SCALEKIT_ENV_URL=https://your-env.scalekit.io
export SCALEKIT_CLIENT_ID=YOUR_CLIENT_ID
export SCALEKIT_CLIENT_SECRET=YOUR_CLIENT_SECRET
export SCALEKIT_REDIRECT_URI=http://localhost:8000/auth/callback

Important:

• Never commit secrets to source control.
• Ensure the redirect URI exactly matches what is configured in Scalekit.

Build and run

# Install dependencies
pip install -r requirements.txt

# Run the application
uvicorn app.main:app --reload --host 0.0.0.0 --port 8000

Or using Python directly:

python -m app.main

The application will start at http://localhost:8000

Setup Scalekit

To find your required values:

1. Visit Scalekit Dashboard and proceed to Settings

2. Copy the API credentials

   • Environment URL (e.g., https://your-env.scalekit.dev)
   • Client ID
   • Client Secret

3. Authentication > Redirect URLs > Allowed redirect URIs:

   • Add http://localhost:8000/auth/callback (no trailing slash)
   • Optionally add http://localhost:8000 as a post-logout redirect

Application routes

Route	Description	Auth required
/	Home page with login option	No
/login	Custom login page	No
/auth/callback	OIDC callback	No
/dashboard	Protected dashboard	Yes
/sessions	Session management	Yes
/sessions/validate-token	Validate token (POST)	Yes
/sessions/refresh-token	Refresh token (POST)	Yes
/organization/settings	Protected settings page	Yes (permission)
/logout	Logout and end session	Yes

🚦 Try the app

1. Start the app (see Quick start)
2. Visit http://localhost:8000
3. Click Sign in with Scalekit
4. Authenticate with your provider
5. Open the dashboard and then try logout

Stuck? Contact us.

Enable debug logging

The application uses Python's standard logging. To enable debug logging, set the DEBUG environment variable to True in your .env file:

DEBUG=True

Code structure

fastapi-scalekit-example/
├── app/                          # Main application package
│   ├── __init__.py
│   ├── main.py                   # FastAPI application entry point
│   ├── config.py                 # Configuration settings
│   ├── routes.py                 # API routes and endpoints
│   ├── scalekit_client.py        # Scalekit OAuth client
│   ├── dependencies.py           # FastAPI dependencies (auth, permissions)
│   └── middleware.py             # Token refresh middleware
├── templates/                    # Jinja2 HTML templates
│   ├── index.html                # Home page
│   ├── login.html                # Login page
│   ├── dashboard.html            # User dashboard
│   ├── sessions.html             # Session management
│   ├── organization_settings.html # Protected settings page
│   ├── error.html                # Error page
│   └── permission_denied.html   # Permission denied page
├── requirements.txt              # Python dependencies
├── .env.example                  # Environment variables template
├── .gitignore
└── README.md                     # This file

Dependencies

• FastAPI 0.104+
• scalekit-sdk-python (Official Scalekit Python SDK)
• python-dotenv (for environment variable management)
• jinja2 (for templating)
• uvicorn (ASGI server)
• starlette (web framework, included with FastAPI)

See requirements.txt for exact versions.

Scalekit SDK Methods Used

This application uses the official Scalekit Python SDK for all authentication operations:

• ScalekitClient.get_authorization_url() - Generate OAuth authorization URL
• ScalekitClient.authenticate_with_code() - Exchange code for tokens
• ScalekitClient.validate_access_token_and_get_claims() - Validate tokens and extract permissions
• ScalekitClient.refresh_access_token() - Refresh expired tokens
• ScalekitClient.get_logout_url() - Generate logout URL

Support

• Read the Scalekit docs: Documentation.
• Read the FastAPI docs: Documentation.

License 📄

This project is for demonstration and learning. Refer to dependency licenses for production use.