Into The Void

Kramerbot - a deal finding Telegram bot

A Telegram bot which scrapes deals from websites like Ozbargain and Amazon

Published on Apr 4 2025 at 12:13pm

Demo

A demo of the bot is running at https://t.me/kramerbot.

Overview

KramerBot is a Telegram bot designed to help users stay updated with the latest deals from websites like www.ozbargain.com.au and Amazon (via CamelCamelCamel). This bot acts as your personal deal hunter, constantly monitoring for the best bargains and notifying you instantly when they’re found.

This bot was created out of a need to find specific deals. Each time I wanted to purchase something online, it was tedious waiting for that product to go on sale. So I decided to write a bot that would notify me when the price dropped below a certain threshold.

Ozbargain is a community driven website where users post deals they find. The deals are voted on by other users and the top deals are displayed on the front page.

Amazon needs no introduction. CamelCamelCamel is a website that scrapes Amazon and provides an API for the price history of a given product.

Key Features

The bot is built using Go and uses the Telegram Bot API to send messages to users. Some of its features are:

Architecture

The architecture of the bot and its main system components are shown in the diagram below:

System Components

graph TD
    A[Telegram Bot API] --> B[KramerBot]
    B --> C[OzBargain Scraper]
    B --> D[Amazon Scraper]
    B --> E[SQLite Database]
    B --> F[Pipup Service]
    C --> G[OzBargain Website]
    D --> H[Amazon/CamelCamelCamel]

Core Components

  1. Bot Core (bot/)

    • Handles Telegram API interactions
    • Manages user commands and responses
    • Processes deal notifications

  2. Scrapers (scrapers/)

    • OzBargainScraper: Monitors OzBargain deals
    • CamCamCamScraper: Tracks Amazon deals via CamelCamelCamel

  3. Data Models (models/)

    • UserData: Stores user preferences and settings
    • Deal structures for different platforms
    • Notification configurations

  4. Persistence Layer

    • SQLite database for user data
    • Deal history tracking
    • User preferences storage

Design

The data model and the flow of the deal processing are shown in the diagrams below:

User Data Model

classDiagram
    class UserData {
        +int64 ChatID
        +string Username
        +bool OzbGood
        +bool OzbSuper
        +bool AmzDaily
        +bool AmzWeekly
        +[]string Keywords
        +[]string OzbSent
        +[]string AmzSent
    }

Deal Processing Flow

sequenceDiagram
    participant S as Scraper
    participant B as Bot
    participant D as Database
    participant U as User
    
    S->>B: New Deal Found
    B->>D: Check Deal History
    D-->>B: Deal Status
    B->>U: Send Notification
    B->>D: Update History

Functionality

User Commands

The bot supports the following commands:

  1. Basic Commands

    • /start - Register or view status
    • /help - Show help message
    • /preferences - View current settings
    • /test - Send test notification

  2. Deal Type Toggles

    • /ozbgood - Toggle OzBargain Good deals
    • /ozbsuper - Toggle OzBargain Super deals
    • /amzdaily - Toggle Amazon Daily deals
    • /amzweekly - Toggle Amazon Weekly deals

  3. Keyword Management

    • /addkeyword <keyword> - Add keyword to watchlist
    • /removekeyword <keyword> - Remove keyword
    • /listkeywords - View current keywords

Deal Processing

  1. Scraping

    • Regular interval-based scraping
    • Configurable scrape intervals
    • Maximum deal storage limits
    • Duplicate detection

  2. Notification

    • Instant Telegram notifications
    • Optional Android TV notifications
    • Deal history tracking
    • Custom formatting for different deal types

Admin Features

Deployment

Requirements

Configuration

Primary configuration through config.yaml: - Scraper intervals - Logging settings - Database paths - Notification settings

Environment variables for sensitive data: - TELEGRAM_BOT_TOKEN - KRAMERBOT_ADMIN_PASS - SQLITE_DB_PATH

Docker Deployment

# Build
docker build -t kramerbot:latest .

# Run
docker run -d --name kramerbot \
  --env-file ./kramerbot.env \
  -v "$(pwd)/data:/app/data" \
  --restart unless-stopped \
  kramerbot:latest

In the pipeline (and some ideas)

  1. Web interface for user management
  2. Additional deal sources
  3. Advanced filtering options
  4. Deal analytics and trends
  5. User preferences synchronization
  6. Enhanced admin dashboard

KramerBot provides a solution for deal hunters who want to stay updated with the latest bargains without constantly checking multiple websites. It has been designed to be modular and easy to extend. New websites can be added by implementing the scraper interface.

Tags: golang , telegram , programming