---
description: "Decompile Android APK/XAPK/JAR/AAR files. Use jadx or Fernflower/Vineflower. Extract Retrofit/OkHttp API endpoints, trace call flows from Activities through ViewModels to network layer."
globs: ["**/*.apk", "**/*.xapk", "**/*.jar", "**/*.aar"]
alwaysApply: false
---

# Android Reverse Engineering

Decompile Android packages using jadx (broad coverage) or Fernflower/Vineflower (higher quality Java). Extract HTTP APIs — Retrofit endpoints, OkHttp calls, hardcoded URLs.

## Quick Start

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

# 2. Install missing deps
bash plugins/android-reverse-engineering/skills/android-reverse-engineering/scripts/install-dep.sh <dep>

# 3. Decompile
bash plugins/android-reverse-engineering/skills/android-reverse-engineering/scripts/decompile.sh app.apk

# 4. Find API calls
bash plugins/android-reverse-engineering/skills/android-reverse-engineering/scripts/find-api-calls.sh output/sources/
```

## Workflow

1. **Verify deps** → run `check-deps.sh`, install any missing with `install-dep.sh`
2. **Decompile** → run `decompile.sh` with `--engine jadx|fernflower|both`
3. **Analyze structure** → AndroidManifest.xml, package layout, architecture patterns
4. **Trace call flows** → Activity → ViewModel → Repository → Retrofit/OkHttp → HTTP
5. **Extract APIs** → run `find-api-calls.sh` with `--retrofit`, `--okhttp`, `--urls`, `--auth`

## Engine Selection

| Situation | Engine |
|---|---|
| General APK analysis | jadx (default) |
| Complex Java decompilation | Fernflower/Vineflower |
| Side-by-side comparison | `--engine both` |
| Obfuscated APK | jadx with `--deobf` |

## API Documentation Format

```markdown
### `METHOD /api/endpoint`
- **Source**: ClassName.java:42
- **Retrofit**: @POST("/api/endpoint")
- **Headers**: Authorization: Bearer {token}
- **Body**: { "key": "value" }
- **Called from**: Activity → ViewModel → Repository → ApiService
```

## References

- `plugins/android-reverse-engineering/skills/android-reverse-engineering/references/setup-guide.md`
- `plugins/android-reverse-engineering/skills/android-reverse-engineering/references/jadx-usage.md`
- `plugins/android-reverse-engineering/skills/android-reverse-engineering/references/fernflower-usage.md`
- `plugins/android-reverse-engineering/skills/android-reverse-engineering/references/api-extraction-patterns.md`
- `plugins/android-reverse-engineering/skills/android-reverse-engineering/references/call-flow-analysis.md`