0xyg3n

Leanrea — Development skill for Claude Code

Development community

One 8 KB skill that replaces REA (Reverse Engineer Anything): plain CLI tools, no MCP.

How to install Leanrea

This entry records only its repository, not the path inside it, so there is no exact command to give. Open 0xyg3n/leanrea and copy the folder into ~/.claude/skills/, or the file into ~/.claude/agents/.

What Leanrea does

One 8 KB skill that replaces REA (Reverse Engineer Anything): plain CLI tools, no MCP. Benchmarked: 38% faster, 35% cheaper.

Alternatives in Development

Understand Anything — Graphs that teach graphs that impress 80.7k ★
Reverse API Engineer — Reverse engineer any website into a typed API client 1.9k ★
Claude Engineer — A version of command line interface(CLI) that leverages the power of Claude Opus(3-4.7) 954 ★

README

leanrea

**One 8 KB skill file that does what [REA](https://github.com/morluto/rea) does: no MCP server, no 207 tools, no setup.**

REA (Reverse Engineer Anything) puts an MCP layer between your agent and tools it can already use: asar, otool, nm, `go version -m`, jadx, apktool, Ghidra, tshark, binwalk, sqlite3. leanrea drops that layer. It tells the agent which command is fastest for each kind of target, gives it ready-to-paste recon commands, and lists the traps that REA's code handles for you. The agent then runs the real tools itself.

	REA 6.5.0	leanrea
What gets installed	25 MB npm package + MCP server	one `SKILL.md`
Instructions	23.5 KB skill + 48.8 KB references	8 KB
Tools added to the agent	207 (3.35 MB of definitions)	0 (uses Bash)
Context for "Reply OK", all tools loaded	400.7k tokens, $1.60	34.5k tokens, $0.09

Benchmark

Claude Code headless (`claude -p`), Sonnet 5.5, macOS arm64. 4 reverse-engineering tasks × 3 reps × 3 arms, with the arms run side by side. Answers are graded against hand-made keys.

arm	total wall time	cost	turns	tokens	score
leanrea	388 s	$2.17	55	2.40 M	74/75
no skill	479 s	$2.21	81	3.11 M	67/75 (one refusal)
REA (MCP + its skill)	627 s	$3.36	124	5.93 M	75/75

Against REA, leanrea had **38% less wall time, 35% lower cost, 56% fewer turns and 60% fewer tokens, at the same accuracy**. Its one partial miss named an older IPC channel instead of the v2 one (both channels exist).

The tasks:

electron: trace a feature through a real Electron app's app.asar (native function → main-process class → IPC channels).
native: inventory the exports, a TCC permission check and the single-instance lock of that app's native addon (.node).
go: toolchain and dependency versions of a stripped gh binary.
deep: from disassembly alone, the exact socket path format, wire p