Build scalable, maintainable, performant webapps one block at a time.
Lego is a modular Python web framework designed to help developers build modern web applications with a component-based approach. It combines the power of FastHTML and MonsterUI with an authentication system and a clean architecture to create performant, maintainable web applications.
- 🧩 Modular Architecture: Build your application block by block, like Lego
- 🔒 Built-in Authentication: Complete auth system with login, registration, password reset, google and github social auth.
- 🎨 Modern UI Components: Responsive UI components with MonsterUI
- 🚀 Fast Rendering: Optimized HTML rendering with FastHTML
- 🌓 Theme Support: Light/dark mode and customizable themes
- 💾 SQLite Database: Simple database integration with WAL mode for performance
- 📨 Resend: Service for sending emails.
- 📝 Logging: Tacks on to uvicorn logging and support and choose between stream and file (for production)
# Clone the repository
git clone https://github.com/karthik777/lego.git
cd lego
# Using Poetry (recommended)
poetry install- Start the server
python main.py- Visit your application
Open your browser and navigate to: http://localhost:5001
lego/
├── main.py # Main application entry point
├── auth/ # Authentication module (example block)
│ ├── app.py # Auth routes and connections
│ ├── cfg.py # Auth configuration
│ ├── data.py # Auth data models and logic
│ └── ui.py # Auth UI components
├── core/ # Core functionality
│ ├── cfg.py # Core configuration
│ └── ui.py # UI components and helpers
├── db/ # Database files
├── static/ # Static assets
└── pyproject.toml # Project dependencies
Lego is built on the concept of modular, composable blocks. Each block can:
- Can set configuration defaults used by it and can also extend it's config with other configs.
- Be completely standalone(own config, database, dependencies)
- Build on top of other blocks(use existing databases, config from one or more components)
- Partially depend on other blocks(use some of the blocks' config or helper methods)
Why?
- Reusability: Blocks can be reused across different applications
- Scalability: Add new features without modifying existing code
- Maintainability: Clean separation of concerns for easier debugging and testing
- Performance: Optimize each block for speed and efficiency
- Flexibility: Mix and match blocks to create custom applications
- Security: Isolate sensitive data and logic in separate blocks
- Consistency: Follow a consistent structure and coding style across blocks
- Environment Generation: Generate environment files, sqlite db automatically from defaults.
This approach allows you to create reusable components that can be mixed and matched to build different applications while maintaining clean separation of concerns.
Lego follows a modular approach where each feature is a "block" that can be connected to the main application:
-
Create a new directory for your block (e.g.,
myblock/) -
Create the following files in your block:
__init__.py- Export yourconnectfunctionapp.py- Define your routes andconnectfunctioncfg.py- Configuration for your blockui.py- Create UI componentsdata.py- Define data models and logic
-
Connect your block in
app.py:
import myblock
# connect your blocks. you can override the routes in blocks placed before the last one
myblock.connect(app)The auth block provides a complete authentication system that can be easily connected to your app:
# In auth/app.py
def connect(app, prefix="/a"):
setup_oath(app)
app.before.append(before)
Routes.base = prefix
app.get("/")(welcome)
app.get(Routes.login)(login)
app.post(Routes.login)(process_login)
# ... more routesLego follows the fast.ai coding style:
- Concise, expressiv 6721 e code
- Focus on readability and maintainability
- Avoid unnecessary abstractions
- Does NOT use ruff or black for formatting
Configuration is managed through .env.override files in the project root and module directories. Default configurations are in core/cfg.py.
- 🚀 Deployment to Fly.io: as it supports Native SQLite support.
- 📨 Email integration: Add support for self-hosted email server with emailwiz
- 🗄️ PostgreSQL support: Add support for PostgreSQL databases
- 📊 Admin dashboard: Built-in admin interface for managing application data
- 🧪 Testing utilities: Helpers for testing blocks and components
- 📚 Documentation generator: Automatic documentation for blocks and APIs
Lego is designed for:
- Web Developers who want a modular, component-based approach to building web applications
- Python Developers looking for a modern alternative to traditional web frameworks
- Rapid Prototypers who need to quickly build functional web applications with authentication
- Teams that want to organize code into reusable, maintainable blocks
MIT