Listing Tracker

WIP

Second hand websites listing tracker

Prerequisites

1. Python 3.x installed.
2. A Telegram account.

Installation

1. Clone or download the repository.
2. Install the required Python dependencies:

pip install -r requirements.txt

Configuration

Before running the script, you need to gather your specific variables and add them to your environment file.

Step 1: Obtaining Environment Variables

1. TELEGRAM_TOKEN (Creating your Bot)

• Open Telegram and search for @BotFather.
• Send the message /newbot to start the creation process.
• Follow the prompts: give your bot a display name and a unique username (must end in bot, e.g., MyBazosTrackerBot).
• @BotFather will reply with a confirmation message containing your HTTP API Token (it will look something like 1234567890:ABCdefGhIJKlmNoPQRsTUVwxyZ). Copy this exact string.

2. CHAT_ID (Connecting to your Bot)

• First, you must activate your new bot. Search for your newly created bot's username in Telegram and send it a message (like /start or "hello"). If you skip this, the bot will not have permission to message you.
• Next, search Telegram for @userinfobot (or @getmyid_bot).
• Send it the message /start.
• It will reply with your personal Id (a string of numbers, e.g., 123456789). Copy this number. This tells the bot exactly who to send the alerts to.

3. SEARCH_URL (Setting your Target)

• Open your web browser and go to www.bazos.cz.
• Search for your desired item.
• Apply any necessary filters directly on the site (e.g., selecting the "Hudba" category, entering your postal code).
• Once the search results show exactly what you want to monitor, copy the entire URL from your browser's address bar (e.g., https://hudba.bazos.cz/?hledat=xone+96...).

Step 2: Setting up the .env file

1. The repository already includes a .env_sample file with the required keys:

TELEGRAM_TOKEN=your_bot_token_here
CHAT_ID=your_chat_id_here
MAX_PRICE_CZK=5000
SEARCH_URL=https://www.bazos.cz/search.php?hledat=your_search_term

2. Copy it to create your active environment file:

cp .env_sample .env

3. Open .env and configure your settings:
   • Paste your TELEGRAM_TOKEN.
   • Paste your CHAT_ID.
   • Set your MAX_PRICE_CZK limit (use numbers only, no currency symbols).
   • Paste your specific SEARCH_URL.

(Note: Ensure your Python script includes from dotenv import load_dotenv and calls load_dotenv() at the top to read these variables using os.getenv('TELEGRAM_TOKEN'), etc.)

Usage

Run the script manually to test it:

python script.py

Note: The first run creates a seen_listings.json file in the same directory to store the URLs of listings it has already alerted you about, preventing duplicate notifications.

Automation

To act as a continuous monitor, schedule the script to run automatically in the background.

Linux/macOS (Cron): Open your terminal, run crontab -e, and add this line to run the script every 15 minutes:

*/15 * * * * cd /absolute/path/to/your/script && /usr/bin/python3 script.py

(Changing into the directory first ensures the script finds the .env and .json files correctly).

Windows:

1. Open Task Scheduler and click Create Task.
2. Under Triggers, set it to run daily, and repeat the task every 15 minutes indefinitely.
3. Under Actions, set the program/script to your python.exe path.
4. Put script.py in the "Add arguments" box.
5. Put the absolute path to your script's folder in the "Start in (optional)" box to ensure it loads the .env file correctly.

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FB Marketplace (!)

This script does not support Facebook Marketplace.

Unlike Bazoš, which uses static HTML and is easy to parse, Facebook actively and aggressively fights automated scraping. Building a custom Python script for Facebook Marketplace is highly discouraged because:

• Dynamic Obfuscation: CSS classes are randomly generated (e.g., <div class="x193iq5w">) and change constantly, making it impossible to reliably target elements like the title or price.
• No Static HTML: Content is rendered dynamically via complex JavaScript.
• Aggressive Blocking: Automated requests without proper session cookies and human-like behavior will quickly result in IP bans or account suspensions.

Recommended Alternatives for Facebook

If you need to monitor Facebook Marketplace, use one of these external tools and solutions instead of a custom script:

1. Browser Extensions (Easiest & Safest) These run directly in your active browser using your existing Facebook login and cookies.

• Distill Web Monitor: The gold standard for this. Select the results grid on FB Marketplace and set it to alert you on changes.
• Visualping: Another popular alternative that visually compares page changes.
• Warning: Set the check interval to 30–60 minutes. Checking too frequently (e.g., every 5 minutes) will get your account temporarily flagged by Facebook.

2. Cloud Scrapers & No-Code Bots (Intermediate) Managed services that maintain the infrastructure, proxies, and code required to bypass anti-bot measures.

• Apify: Has pre-built "Actors" specifically designed to scrape Facebook Marketplace into clean JSON data. You will likely need to provide session cookies from a "burner" account.
• Browse AI: A no-code platform where you can record yourself navigating Facebook Marketplace, and it will build a monitoring robot based on your actions.

3. Headless Browsers (For Developers) If you insist on writing the code yourself, you must mimic human behavior in an invisible browser. It is incredibly fragile and requires constant maintenance.

• Playwright: Microsoft's modern browser automation framework.
• Selenium: The legacy standard for browser automation.
• Puppeteer: Google's Node.js API for Chrome/Chromium.