# P1sec/hermes-dec

A reverse engineering tool for decompiling and disassembling the React Native Hermes bytecode

Repository: https://github.com/P1sec/hermes-dec
Canonical: https://ross.abutalabs.com/products/hermes-dec
Language: Python
License: AGPL-3.0
License Family: copyleft
Topics: reverse-engineering, hermes, react-native, decompiler, javascript
Last push: 2026-08-11T04:17:31+00:00

## Health v2 (maintenance only)
Score: 98/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 97, release rhythm 97, longevity 100
- inputs: {"age_days": 1412, "days_push": 22, "days_rel": 22, "gap_med": 18, "n_releases_24m": 8}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1156, forks 94 (observed 2026-08-28T04:03:47.960144+00:00)

## What it is
hermes-dec is a Python-based reverse engineering tool that disassembles and decompiles React Native applications compiled to the Hermes VM bytecode (HBC) format. It parses Hermes bytecode files such as assets/index.android.bundle from Android APKs and produces readable disassembly or decompiled output.

## Use cases
- decompile hermes bytecode from a react native android app
- disassemble index.android.bundle hbc files
- analyze react native mobile app internals for security research
- reverse engineer a react native ios app using hermes
- inspect hermes vm bytecode version 84
- audit third-party react native applications

## When to choose
- you need to analyze or audit a React Native app compiled with the Hermes engine
- you want an open-source disassembler/decompiler for HBC files
- you prefer a dependency-free Python 3 tool installable via pipx, uv, snap, or AUR

## When to avoid
- the target app uses plain minified JavaScript instead of Hermes bytecode
- you need a full JavaScript decompiler for non-Hermes bundles
- you need a GUI-based reverse engineering suite

## Facets
- artifact type: cli-tool
- maturity: active
- function: reverse-engineering, parser, developer-tools
- domain: reverse-engineering, mobile-development, security, developer-tools
- platform: python, cli, cross-platform
- tags: hermes, react-native, decompiler, disassembler, bytecode, hbc, javascript

## Member repositories
- P1sec/hermes-dec (main) score 98

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:47.960144+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:32:06.212098+00:00, confidence not recorded.
  - readme: https://github.com/P1sec/hermes-dec (fetched 2026-08-28T04:03:47.960144+00:00, sha b67f3adf49e7)
  - registry_pypi: https://pypi.org/pypi/hermes-dec/json (fetched 2026-08-29T12:37:08.932017+00:00, sha 50bbdf077576)
- Data as of 2026-08-30T08:39:29.467469+00:00.