This repository contains additional data, documentation, and tooling from our reverse-engineering of WeChat's network protocol. Related publications:

• What WeChat Knows: Pervasive First-Party Tracking in a Billion-User Super-App Ecosystem (PETS 2025)
• Security analysis of WeChat's MMTLS (2024)
• Privacy in the WeChat Ecosystem (2023)

docs/ has further documentation, RE notes, and pseudocode on the MMTLS format and WeChat network requests in general. In particular, we recommend starting with this key overview of WeChat's request sending infrastructure.

data/ contains sample network traffic traces, including decrypted traces.

code/ contains our Frida code, tooling, and setup guides for intercepting and decrypting WeChat traffic on your own device.