jvm-decompile

jvm-decompile is a skill for Claude Code, Codex from batteryshark/rekit. It costs 73 tokens per session (332 once invoked), scanned A, original, Apache-2.0.

A static decompiler that reconstructs Java source from Android and Java bytecode files such as APKs, DEX files, JARs, and CLASS files. It reads the bytecode and never runs it.

In plain words
What is it for?
Use it to inspect Android apps and Java archives, recover readable source files, and review their behavior; it requires the separate jadx tool and a Java runtime.
Why use it?
Compiled Java code is harder to review than source, so decompilation helps you understand an app or library when its original source is unavailable.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to inspect Android apps and Java archives, recover readable source files, and review their behavior; it requires the separate jadx tool and a Java runtime.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/batteryshark/rekit/jvm-decompile
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.

Any agent
npx skills add batteryshark/rekit --skill jvm-decompile
Clone the repo
git clone --depth 1 https://github.com/batteryshark/rekit

Made for: Claude Code, Codex.

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 jvm-decompile

README.md
[![agentmods](https://agentmods.dev/badge/skills/batteryshark/rekit/jvm-decompile/github.svg)](https://agentmods.dev/skills/batteryshark/rekit/jvm-decompile)
Your own site
<a href="https://agentmods.dev/skills/batteryshark/rekit/jvm-decompile"><img src="https://agentmods.dev/badge/skills/batteryshark/rekit/jvm-decompile/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for jvm-decompile

Your own site · 80×15
<a href="https://agentmods.dev/skills/batteryshark/rekit/jvm-decompile"><img src="https://agentmods.dev/badge/skills/batteryshark/rekit/jvm-decompile.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 73 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 332 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00073 $0.00332
Opus 5.5 $0.00029 $0.00133
Sonnet 5.5 $0.00015 $0.00066
Haiku 4.5 $0.00007 $0.00033

Measured 1mo ago against content hash 7edba07b143a, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

jvm-decompile scanned grade A with 0 findings 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 1mo ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/run.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/jvm-decompile/SKILL.md · 33 lines

What it actually says

JVM / Android Decompiler

Decompile Java/Android bytecode (.apk / .dex / .jar / .class) back to Java source with jadx.

When to use

An Android app or Java archive you need to read. Extract nested archives with unpack first if needed, then decompile the .dex/.jar and review the .java.

What it does

Runs jadx -d <outdir> <input> (static — jadx reconstructs source from bytecode and never executes it) and reports how many files were written.

Prerequisites

  • python3 (runner) and jadx on PATH. jadx is a large JVM application that needs a JRE (java ≥ 11), so it is not bundled — install it and put it on PATH. Until then rekit doctor shows this skill as not-ready and run reports the honest blind spot with an install hint (nothing is silently skipped).

Usage

rekit run jvm-decompile ./app.apk ./out
Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 1mo ago First seen · 33 lines · 73 tokens per session scan A 7edba07b143a

Subscribe to this mod's changes

jvm-decompile is a skill published in the GitHub repository batteryshark/rekit (20 stars, last pushed 2mo ago), licensed Apache-2.0. It adds 73 tokens to every session and 332 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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