Android Reverse Flow

Use this skill for end-to-end Android APK reversing on the phone.

Quick rules

• Use the MCP shell tool as the main control surface.
• Keep shell output narrow. Prefer redirects, rg, sed -n, jq, head, and tail over dumping full trees or files.
• For iterative work, prefer a persistent shell session over restarting one-shot commands.
• On Android/Termux, treat plain apktool b ... as an anti-pattern. Always force --aapt /data/data/com.termux/files/usr/bin/aapt2.
• Prefer separate working directories per APK and per iteration.
• Treat apktool output as the editable source of truth for resources/manifest/smali. Treat jadx output as read-mostly navigation.

Standard flow

1. Verify toolchain and environment first.
2. Copy the target APK into a disposable work directory.
3. Decode once with apktool d.
4. Inspect Java/Kotlin structure with jadx or jadx-cli.
5. Patch the smallest layer possible:

manifest/resource first if enough; smali only if resource-level patching is not enough.

1. Rebuild with the helper script or apktool b --aapt ....
2. Sign the rebuilt APK.
3. Install, launch, and capture failures.
4. Iterate from the exact failing step instead of re-running the full chain.

Shell usage patterns

• Before reading big directories, ask for counts or filtered paths.
• Before reading large XML or smali files, pull only relevant slices with rg -n and sed -n.
• When a build command is noisy, redirect stdout/stderr to files and inspect the tail first.
• If a workflow becomes interactive or iterative, stay inside one shell session instead of reopening commands repeatedly.

When to read references

• Read references/reverse-workflow.md for the concrete decode -> patch -> rebuild -> sign -> install loop.
• Read references/termux-shell-patterns.md for low-context shell habits and command templates.
• If rebuild fails around apktool, resources, or aapt2, use the separate apktool-termux-troubleshooting skill.

Preferred helper

• Prefer scripts/apktool-build-termux.sh for rebuilds on the phone instead of rewriting the full apktool b ... --aapt ... command each time.