Facebook BitMap Codec (Python)

A professional Python tool for encoding and decoding Facebook API parameters.

This project implements a reverse-engineered compression algorithm used by Facebook (BitMap + Run-Length Encoding + Custom Base64) to manage critical API parameters. It allows you to generate 100% valid and authentic-looking request payloads.

🚀 Key Features

• Universal Support: Fully compatible with all parameters utilizing BitMap techniques:
  • __dyn (Dynamic Loaded Modules)
  • __csr (Client Side Resources / CSS)
  • __hsdp (HTML Server Data Parameter)
  • __hblp (HTML BigPipe Last Parameter)
  • __sjsp (Server JS Parameter)
• Reversible Logic: Seamlessly converts between raw IDs and encoded strings with zero data loss.
• Safety Filter: Built-in protection against memory overflow errors by automatically filtering out invalid or excessively large IDs (e.g., timestamps).
• Clean & Professional: Implemented as a clean, easy-to-use Python class (FacebookCodec) with type hinting support.

🛠️ Installation

1. Clone this repository to your local machine:

   git clone https://github.com/NiceDayZc/FacebookCodec.git
   cd FacebookCodec

2. Ensure that FCodec.py is present in your project directory.

💻 Usage

Simply import the FacebookCodec class from FCodec.py to get started.

1. Encoding

Use this to generate parameters like __dyn or __csr for your API requests.

from FCodec import FacebookCodec

# Initialize the codec
codec = FacebookCodec()

# Example list of IDs (e.g., extracted from 'rsrcMap' in HTML)
js_modules = [17, 25, 30, 100, 101, 102, 500] 

# Generate the encoded string
dyn_value = codec.encode(js_modules)

print(f"Generated __dyn: {dyn_value}")
# Output: 7xeUjGU... (Ready-to-use string)