Telegram Auto-Forwarding Bot

This project implements a Telegram bot using Telethon and FastAPI that automatically forwards messages from specified source channels to a target channel.

Repository Structure

The repository is structured as follows:

.
└── app
    ├── __init__.py
    ├── api
    │   ├── __init__.py
    │   ├── health_check.py
    │   └── telegram.py
    ├── main.py
    ├── settings.py
    └── telegram
        ├── __init__.py
        ├── client.py
        └── instance.py

Key Files:

• app/main.py: The entry point of the FastAPI application.
• app/api/telegram.py: Handles message forwarding logic.
• app/api/health_check.py: Implements health check endpoint.
• app/telegram/client.py: Contains the Telethon client implementation.
• app/telegram/instance.py: Manages Telegram client instance.
• app/settings.py: Stores configuration settings for the application.

Usage Instructions

Installation

1. Ensure you have Python 3.11 or later installed.
2. Clone the repository:

   git clone <repository-url>
   cd <repository-name>
   

3. Create and activate a virtual environment:

   python -m venv .venv
   source .venv/bin/activate  # On Windows, use `.venv\Scripts\activate`
   

4. Install the required dependencies using uv:

   uv pip install -r requirements.txt
   

Configuration

1. Create a .env file in the root directory with the following variables:

   # Telegram API credentials
   TELEGRAM__API_ID=your_api_id
   TELEGRAM__API_HASH=your_api_hash
   
   # Channel configuration
   TELEGRAM__CHANNELS=channel1_id,channel2_id,channel3_id  # Source channels to monitor
   TELEGRAM__TARGET_CHANNEL_ID=target_channel_id  # Channel where messages will be forwarded
   

2. To obtain your API credentials:

   • Go to https://my.telegram.org/auth
   • Log in with your phone number
   • Go to 'API development tools'
   • Create a new application to get your API_ID and API_HASH

Running the Application

To start the FastAPI server:

uv run fastapi dev app/main.py

The server will start, and you can access the API documentation at http://localhost:8000/docs.

How It Works

1. The bot monitors the specified source channels (TELEGRAM__CHANNELS)
2. When a new message is posted in any of the source channels, the bot automatically forwards it to the target channel ( TELEGRAM__TARGET_CHANNEL_ID)
3. The FastAPI application provides an interface to monitor the bot's status and operations

[Source Channels] -> [Telethon Client] -> [Target Channel]

API Endpoints

• livez/redyz: Health check endpoint to verify the service is running
• telegram/channels: Channels CRUD

Deployment

For deployment, consider using a production-grade ASGI server like Gunicorn with Uvicorn workers:

gunicorn app.main:app --workers 4 --worker-class uvicorn.workers.UvicornWorker --bind 0.0.0.0:8000

Ensure to set up proper SSL/TLS for secure communication when deploying to production.

Important Notes

• Make sure your Telegram account has the necessary permissions to access the source channels and post in the target channel
• Be mindful of Telegram's rate limits when configuring multiple source channels
• Keep your API credentials secure and never commit them to version control