A reverse-engineering tool for examining shipped software when its source code is unavailable. It inspects compiled apps, websites, Android packages, firmware and other built files, then reports findings with evidence IDs.

Use it to inspect desktop and Electron apps, command-line tools, websites, Android apps, .NET assemblies and firmware. It can also set up and run the REA command-line tool or MCP server.

It replaces guesses based on documentation or memory with observations from the actual software artifact. This helps determine how a feature really works without access to its source code.

rea — Skill for Claude Code and Codex by anton-abyzov/vskill

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 anton-abyzov/vskill --skill rea

Clone the repo

git clone --depth 1 https://github.com/anton-abyzov/vskill

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/anton-abyzov/vskill/rea/github.svg)](https://agentmods.dev/skills/anton-abyzov/vskill/rea)

Your own site

<a href="https://agentmods.dev/skills/anton-abyzov/vskill/rea"><img src="https://agentmods.dev/badge/skills/anton-abyzov/vskill/rea/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/anton-abyzov/vskill/rea"><img src="https://agentmods.dev/badge/skills/anton-abyzov/vskill/rea.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 184 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,091 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.

Model	Per session	Once invoked
Fable 5.1	$0.00184	$0.02091
Opus 5.5	$0.00074	$0.00836
Sonnet 5.5	$0.00037	$0.00418
Haiku 4.5	$0.00018	$0.00209

Measured 11d ago against content hash 349ed8013d4b, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

rea 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 11d 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.

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/rea/SKILL.md · 154 lines

How it starts

The opening of the file, as written. The whole thing — 154 lines — stays where its author put it; the contents beside it link to each section on GitHub.

REA: learn how a shipped feature really works

When you need to know how a feature is implemented in a specific tool or app, do not guess from docs, marketing pages or memory. Look at the shipped artifact with REA and cite what you found.

REA (Reverse Engineer Anything) is an MIT-licensed CLI and MCP server by morluto. It decompiles and inspects native binaries (through Hopper, Ghidra or IDA), Electron/JavaScript bundles, websites, Android APKs, .NET assemblies, firmware and more, and returns Evidence records with IDs you can cite.

This skill is the entry point: set up, route, run, report. REA's own reverse-engineer-anything skill holds the detailed per-tool workflow; load it when it is installed.

0. Is the source available?

If the code is in a repo you can read (open source, the user's own project, an npm package with readable source), read it with normal tools. REA is for shipped artifacts: compiled binaries, minified bundles, signed apps.

1. Check the setup (once per machine, not per task)

If the REA MCP tools (open_binary, analyze_javascript_application, ...) are already in your tool list, or rea --version works, skip straight to step 2. Don't run diagnostics before every investigation. Only when something is missing or a call fails:

rea doctor --client claude_code --json         # or --client codex

Missing pieces, in order:

CLI. Official package only: npm i -g rea-agents@latest (Node ^22.19, ^24.11 or >=26; 23 and 25 are unsupported). No install scripts; npm provenance is attached.
Agent registration. Plan first, then apply:
```
rea setup --client claude_code --client codex --skill=false --dry-run --json
rea setup --client claude_code --client codex --skill=false --yes --json
```
Add --install-hopper on macOS to download Hopper from hopperapp.com (codesign-verified, installed to ~/Applications). Setup then opens the Hopper app once: tell the user before you run it, because a person has to click "Try the Demo" (or enter a license) in its first-run window before REA can drive it unattended. Hopper is only needed for native binaries; Electron, JavaScript, web, APK and .NET work without it. Restart the agent afterwards so it sees the tools. Setup writes HOPPER_LAUNCHER_PATH only into the agents' MCP entries. The rea CLI looks in /Applications, so when Hopper went to ~/Applications export it in the shell profile too: export HOPPER_LAUNCHER_PATH="$HOME/Applications/Hopper Disassembler.app/Contents/MacOS/hopper". A first open can time out while Hopper is still starting; retry once.
REA's own workflow skill (optional, recommended): rea setup --skill --dry-run --json shows the destinations (~/.agents/skills plus each registered agent's skill folder), then --yes installs. If the machine keeps one canonical copy in ~/.agents/skills with links from agent folders, replace the per-agent copy with a link to the shared one.

Read the full file on GitHub · 154 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.

11d ago First seen · 154 lines · 184 tokens per session scan A 349ed8013d4b

Subscribe to this mod's changes

rea is a skill published in the GitHub repository anton-abyzov/vskill (48 stars, last pushed yesterday), licensed MIT. It adds 184 tokens to every session and 2,091 once invoked, about $0.0007 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 2026-10-12.

Claude Code Research ai ai-agents cli copilot cursor

rea

Getting it into your agent

Wrote this? Show the measurements

What it costs to keep this loaded

Grade A, and why

Nothing flagged

How it starts

REA: learn how a shipped feature really works

0. Is the source available?

1. Check the setup (once per machine, not per task)

What this file has done since we first saw it

Other skills, from other repositories

start-coding-task

review-agent-work

continue-with-codeagent-credits

supervise-session

prereview

agent-config-setup