jadx

jadx is a skill for Claude Code, Codex from BrownFineSecurity/iothackbot. It costs 51 tokens per session (4,668 once invoked), scanned A, original, MIT.

A guide for using JADX, an Android APK decompiler that turns an app’s compiled DEX code into readable Java-like source.

In plain words
What is it for?
Decompiling APKs, tracing app behaviour, searching for vulnerabilities or embedded secrets, and reviewing authentication or encryption code.
Why use it?
It makes an Android app’s internal logic easier to inspect when the original source code is unavailable.

Skill for Claude CodeCodex

Part of the iothackbot plugin — 13 skills shipped together

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/brownfinesecurity/iothackbot/jadx
Any agent
npx skills add BrownFineSecurity/iothackbot --skill jadx
Clone the repo
git clone --depth 1 https://github.com/BrownFineSecurity/iothackbot

Made for: Claude Code, Codex.

Or install iothackbot, the plugin that ships this one along with the rest of its 13 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for jadx

README.md
[![agentmods](https://agentmods.dev/badge/skills/brownfinesecurity/iothackbot/jadx.svg)](https://agentmods.dev/skills/brownfinesecurity/iothackbot/jadx)
Your own site
<a href="https://agentmods.dev/skills/brownfinesecurity/iothackbot/jadx"><img src="https://agentmods.dev/badge/skills/brownfinesecurity/iothackbot/jadx.svg" alt="Measured on agentmods" height="20"></a>
Per session 51 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,668 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00051 $0.04668
Opus 5 $0.00026 $0.02334
Sonnet 5 $0.00010 $0.00934
Haiku 4.5 $0.00005 $0.00467

Measured 5d ago against content hash c26ec3f58de5, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

jadx scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

- Test endpoints with curl/burp
skills/jadx/SKILL.md · 663 lines

How it starts

The opening of the file, as written. The whole thing — 663 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Jadx - Android APK Decompiler

You are helping the user decompile Android APK files using jadx to convert DEX bytecode into readable Java source code for security analysis, vulnerability discovery, and understanding app internals.

Tool Overview

Jadx is a dex to Java decompiler that produces clean, readable Java source code from Android APK files. Unlike apktool (which produces smali), jadx generates actual Java code that's much easier to read and analyze. It's essential for:

  • Converting DEX bytecode to readable Java source
  • Understanding app logic and control flow
  • Finding security vulnerabilities in code
  • Discovering hardcoded credentials, API keys, URLs
  • Analyzing encryption/authentication implementations
  • Searching through code with familiar Java syntax

Prerequisites

  • jadx (and optionally jadx-gui) must be installed
  • Java Runtime Environment (JRE) required
  • Sufficient disk space (decompiled output is typically 3-10x APK size)
  • Write permissions in output directory

GUI vs CLI

Jadx provides two interfaces:

CLI (jadx): Command-line interface

  • Best for automation and scripting
  • Batch processing multiple APKs
  • Integration with other tools
  • Headless server environments

GUI (jadx-gui): Graphical interface

  • Interactive code browsing
  • Built-in search functionality
  • Cross-references and navigation
  • Easier for manual analysis
  • Syntax highlighting

When to use each:

  • Use CLI for automated analysis, scripting, CI/CD pipelines
  • Use GUI for interactive exploration and deep-dive analysis

Instructions

1. Basic APK Decompilation (Most Common)

Standard decompile command:

jadx <apk-file> -d <output-directory>

Example:

jadx app.apk -d app-decompiled

With deobfuscation (recommended for obfuscated apps):

jadx --deobf app.apk -d app-decompiled

2. Understanding Output Structure

After decompilation, the output directory contains:

app-decompiled/
├── sources/                           # Java source code
│   └── com/company/app/              # Package structure
│       ├── MainActivity.java
│       ├── utils/
│       ├── network/
│       └── ...
└── resources/                         # Decoded resources
    ├── AndroidManifest.xml           # Readable manifest
    ├── res/                          # Resources
    │   ├── layout/                   # XML layouts
    │   ├── values/                   # Strings, colors
    │   ├── drawable/                 # Images
    │   └── ...
    └── assets/                       # App assets

Read the full file on GitHub · 663 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago First seen · 663 lines · 51 tokens per session scan A c26ec3f58de5

Subscribe to this mod's changes

jadx is a skill published in the GitHub repository BrownFineSecurity/iothackbot (825 stars, last pushed 3mo ago), licensed MIT. It adds 51 tokens to every session and 4,668 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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