Hermes-Dec Bytecode Reverse Engineering

Skill by ara.so — Hermes Skills collection.

Overview

hermes-dec is a reverse-engineering tool for disassembling and decompiling React Native applications compiled to Hermes VM bytecode (HBC) format. It provides three main utilities:

• hbc-file-parser: Parse and display HBC file headers and metadata
• hbc-disassembler: Convert bytecode to assembly-like representation (.hasm)
• hbc-decompiler: Decompile bytecode to pseudo-JavaScript code

Hermes is the default JavaScript engine for React Native on Android (since RN 0.70) and is commonly found in mobile apps at assets/index.android.bundle.

Installation

# Using pipx (recommended for CLI tools)
pipx install hermes-dec