decx

DECX - Decompiler + X

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Overview

DECX (Decompiler + X) is a smart code analysis platform built on the JADX decompiler, designed specifically for AI-assisted code analysis. The platform provides powerful Java code analysis capabilities to AI assistants through HTTP API and MCP (Model Context Protocol).

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Installation

Prerequisites

• Java: JDK 11+
• Node.js: 18+ for the CLI
• JADX: v1.5.2+ with plugin support if you use the GUI plugin
• Python: 3.10+ or uv for the plugin MCP sidecar; without uv, ensure requests, fastmcp, and pydantic are available

CLI And AI Skills

For AI-assisted CLI work, install the CLI, install the DECX server JAR, then expose the bundled skills to your agent:

npm install -g @jygzyc/decx-cli
decx self install
git clone https://github.com/jygzyc/decx ~/.decx/source
mkdir -p ~/.agents
ln -s ~/.decx/source/skills ~/.agents/skills

Replace ~/.agents/skills with the skills directory expected by your agent:

Agent	Link target
Claude Code	~/.claude/skills
Opencode	~/.config/opencode/skills
Codex	~/.codex/skills
Common agent setup	~/.agents/skills

The skills/ directory contains:

Skill	Use
decxcli	General code navigation, source lookup, xrefs, manifest, and resource inspection
decxcli-app-vulnhunt	APK attack-surface enumeration, component/WebView/IPC tracing, exploitability triage, and bilingual reports
decxcli-framework-vulnhunt	Android framework and Binder/service vulnerability hunting on the processed final framework bundle
decxcli-poc	Build a focused Android PoC app and optional helper server from one confirmed finding

JADX Plugin

Install the plugin from the JADX GUI plugin manager, or install a plugin JAR manually:

jadx plugins --install-jar <path-to-jadx_decx_plugin.jar>

After installation, open an APK/JAR in JADX and enable DECX. The plugin exposes the DECX HTTP API and MCP tools for the currently opened JADX project.

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Usage

CLI + Skills

For agent-driven analysis, use the CLI to create a session and let the installed skills drive the detailed workflow:

decx process open target.apk --name target
decx code classes --limit 50
decx code search-global "WebView" --limit 20
decx ard exported-components
decx ard app-deeplinks
decx process close target
decx process close --port 25419

Typical skill sequence:

• decxcli for exploration and evidence gathering
• decxcli-app-vulnhunt or decxcli-framework-vulnhunt for focused vulnerability hunting
• decxcli-poc for turning one confirmed finding into a buildable PoC

Useful command groups:

Need	Commands
Session lifecycle	decx process open <file>, decx process list, decx process check, decx process close [name] [--port <port>]
Code analysis	decx code classes, class-source, method-source, method-context, search-global, search-class, xref-method, xref-class, xref-field, implement, subclass
APK analysis	decx ard app-manifest, main-activity, app-application, exported-components, app-deeplinks, app-receivers, get-aidl, all-resources, resource-file, strings
Framework analysis	decx ard framework collect, process <oem>, run, open [jar], plus system-service-impl <interface>
Live device helpers	decx ard system-services, decx ard perm-info <permission>
CLI/server management	decx self install, decx self update

Notes:

• Session-backed code and ard commands support --page <n> and can target a session with -s, --session <name> or a port with -P, --port <port>.
• decx code class-source supports --limit <n> to return at most N source lines.
• decx process open <file> passes standard jadx-cli flags through and enables --show-bad-code by default.
• decx ard all-resources supports file-name filtering with --include and --no-regex.
• system-services and perm-info are adb-backed commands. They use --serial / --adb-path, not -P <port>.
• decx ard framework run collects from the connected device, processes, packs, and opens the final framework JAR by default; process <oem> is for local framework dumps.

Plugin + MCP

Use the plugin when you want the AI assistant to work against the project already opened in JADX GUI: