android-reverse-engineering

Android Reverse Engineering & API Extraction — Claude Code skill

A Claude Code skill that decompiles Android APK/XAPK/JAR/AAR files and extracts the HTTP APIs used by the app — Retrofit endpoints, OkHttp calls, hardcoded URLs, authentication patterns — so you can document and reproduce them without the original source code.

First-class Kotlin support: modern Android apps are Kotlin/KMP, heavily obfuscated with R8. This skill recovers the original Kotlin class names from metadata R8 cannot strip, and extracts APIs from Ktor, Apollo (GraphQL) and Koin — not just the classic Retrofit/OkHttp stack. See Kotlin name recovery below.

Windows / PowerShell support (experimental): The *.ps1 scripts alongside the bash ones are a recent community contribution, still being stabilised. For any issues please open an issue on this repository (not on the contributors' upstream forks): the PowerShell scripts are maintained here by @SimoneAvogadro.

Table of Contents

• What it does
• Requirements
• Installation
• Usage
• Repository Structure
• References
• Acknowledgments
• Disclaimer
• License

What it does

Capability	Description
Fingerprint first (Phase 0)	Triage an APK/XAPK in seconds — detect the framework (Flutter / React Native / Cordova / Xamarin / native-Kotlin), HTTP stack, obfuscation level and native libs before spending time on a full decompile
Decompile	APK, XAPK, JAR, and AAR files using jadx and Fernflower/Vineflower (single engine or side-by-side comparison)
Recover Kotlin names	Rebuild original *Repository / *ViewModel / *UseCase class names from R8-obfuscated binaries using Kotlin metadata that R8 cannot strip
Extract APIs	Retrofit, OkHttp, Volley and modern Kotlin/KMP stacks: Ktor, Apollo (GraphQL), Koin DI — endpoints, hardcoded URLs, auth headers, tokens and HMAC request-signing schemes
Trace call flows	From Activities/Fragments through ViewModels and repositories down to HTTP calls
Analyze structure	Manifest, packages, architecture patterns
Handle obfuscation	R8-resistant path/URL extraction plus strategies for navigating ProGuard/R8 output

Requirements

Required:

• Java JDK 17+
• jadx (CLI)

Optional (recommended):

• Vineflower or Fernflower — better output on complex Java code
• dex2jar — needed to use Fernflower on APK/DEX files

See plugins/android-reverse-engineering/skills/android-reverse-engineering/references/setup-guide.md for detailed installation instructions.

Installation

From GitHub (recommended)

Inside Claude Code, run:

/plugin marketplace add SimoneAvogadro/android-reverse-engineering-skill
/plugin install android-reverse-engineering@android-reverse-engineering-skill

The skill will be permanently available in all future sessions.

From a local clone

git clone https://github.com/SimoneAvogadro/android-reverse-engineering-skill.git

Then in Claude Code:

/plugin marketplace add /path/to/android-reverse-engineering-skill
/plugin install android-reverse-engineering@android-reverse-engineering-skill

Usage

Slash command

/decompile path/to/app.apk

This runs the full workflow: dependency check, decompilation, and initial structure analysis.

Natural language

The skill activates on phrases like:

• "Decompile this APK"
• "Reverse engineer this Android app"
• "Extract API endpoints from this app"
• "Follow the call flow from LoginActivity"
• "Analyze this AAR library"

Manual scripts

The scripts can also be used standalone:

# Check dependencies
bash plugins/android-reverse-engineering/skills/android-reverse-engineering/scripts/check-deps.sh

# Install a missing dependency (auto-detects OS and package manager)
bash plugins/android-reverse-engineering/skills/android-reverse-engineering/scripts/install-dep.sh jadx
bash plugins/android-reverse-engineering/skills/android-reverse-engineering/scripts/install-dep.sh vineflower