A production-ready notification service built with Python that supports multiple channels, templating, and event-driven architecture.

• Multiple Notification Channels: Email, Slack, and extensible for more
• Template Engine: Jinja2-based templating for dynamic message content
• Event Sources: Real-time and scheduled event processing
• Deduplication: Configurable deduplication policies to prevent spam
• Modular Architecture: Clean separation of concerns with dependency injection
• Production Ready: Proper logging, configuration management, and error handling

upwork/
├── src/                    # Source code package
│   ├── __init__.py        # Package initialization
│   ├── channels.py        # Notification channel implementations
│   ├── templates.py       # Template rendering engine
│   ├── templates_data.py  # Template definitions
│   ├── events.py          # Event source implementations
│   ├── deduplication.py   # Deduplication policies
│   ├── registry.py        # Notification configuration registry
│   ├── service.py         # Main notification service
│   └── config.py          # Application configuration
├── main.py                # Application entry point
├── pyproject.toml         # Project dependencies
└── README.md             # This file

• Python 3.12+
• uv (Python package manager)

1. Clone the repository
2. Install dependencies:

   uv sync

uv run python main.py

This will:

• Process user signup events
• Send welcome emails and Slack notifications
• Generate daily statistics reports

• EmailChannel: Writes notifications to log files
• SlackChannel: Prints notifications to console (mock implementation)
• Extensible: Add new channels by implementing NotificationChannel

• Jinja2-based template rendering
• Supports dynamic content with context variables
• Templates stored in src/templates_data.py

• RealTimeSource: Processes immediate events
• ScheduledSource: Queries databases for scheduled reports
• Extensible: Add new sources by implementing EventSource

• SimpleDedupPolicy: In-memory deduplication by event ID
• Prevents duplicate notifications
• Each notification config can have its own policy

• Orchestrates the entire notification workflow
• Processes events, renders templates, and sends notifications

Environment variables can be set to configure the service:

export EMAIL_OUTPUT_DIR="./logs"
export DEFAULT_SLACK_CHANNEL="#alerts"
export ENABLE_EMAIL=true
export ENABLE_SLACK=true

1. Implement NotificationChannel in src/channels.py:

   class DiscordChannel(NotificationChannel):
       def __init__(self, webhook_url: str):
           self.webhook_url = webhook_url
       
       def send(self, message: str) -> None:
           # Implementation here
           pass

2. Register in your notification configuration:

   discord_channel = DiscordChannel(webhook_url="https://...")
   registry.register(NotificationConfig(
       name='Discord Alert',
       channel=discord_channel,
       template_name='alert_discord.txt',
       event_source=event_source,
       dedup_policy=SimpleDedupPolicy(),
   ))

1. Add template to src/templates_data.py:

   TEMPLATES = {
       # ... existing templates
       'alert_discord.txt': "🚨 {{ message }} - {{ timestamp }}",
   }

2. Reference in notification configuration:

   template_name='alert_discord.txt'

1. Implement EventSource in src/events.py:

   class APISource(EventSource):
       def __init__(self, api_url: str):
           self.api_url = api_url
       
       def fetch(self) -> List[Dict[str, Any]]:
           # Fetch from API
           return events

2. Use in notification configuration:

   api_source = APISource(api_url="https://api.example.com/events")

uv run pytest

This project follows PEP 8 and uses type hints throughout.

uv add package-name

FROM python:3.12-slim
WORKDIR /app
COPY . .
RUN pip install uv && uv sync --frozen
CMD ["uv", "run", "python", "main.py"]

Set up environment variables for production:

export DATABASE_URL="postgresql://user:pass@host/db"
export LOG_LEVEL="INFO"
export EMAIL_OUTPUT_DIR="/var/log/notifications"

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests if applicable
5. Submit a pull request

MIT License - see LICENSE file for details.