crg-lean 1.0.0

Token-efficient code-review-graph wrapper for AI coding agents

crg-lean

Token-efficient wrapper for code-review-graph.

The raw code-review-graph MCP tools return 15k–24k tokens per query — full absolute paths, raw graph edges, source code dumps. crg-lean strips the fat, converts paths to relative, and returns only what's useful: 10–87× fewer tokens per query.

Real measurements (53-file Next.js project)

Query	Raw MCP	crg-lean	Reduction
detect changes	~5,456 tok	~156 tok	35×
impact radius	~15,517 tok	~179 tok	87×
minimal context	~101 tok	~73 tok	1.4×

Requirements

• Python 3.8+
• code-review-graph (pip install code-review-graph)

Install

bash install.sh

Or manually:

cp crg-lean ~/.local/bin/crg-lean
chmod +x ~/.local/bin/crg-lean

One-command project setup

Run once in any project directory:

crg-lean setup

This automatically:

1. Installs code-review-graph if missing (tries pipx → uv → pip)
2. Builds the code graph
3. Adds .code-review-graph/ to .gitignore
4. Wires SessionStart + PostToolUse hooks in .claude/settings.json
5. Installs post-commit, post-merge, post-rebase git hooks (monorepo-aware)
6. Creates/updates CLAUDE.md with an architecture section

Idempotent — safe to re-run, skips steps already done.

Commands

crg-lean setup                   # bootstrap a project (run once)
crg-lean changes                 # what changed since last commit + risk score
crg-lean find "<symbol>"         # locate a symbol → file:start-end (N lines)
crg-lean impact [file ...]       # blast radius — which files are affected
crg-lean context "<concept>"     # keyword search — does this already exist?
crg-lean stats                   # graph overview (files, nodes, languages)
crg-lean update-claude           # refresh architecture section in CLAUDE.md

Surgical read workflow

# 1. Find exact location
crg-lean find "authenticate"
# → src/utils/jwt.ts:7-18  (12 lines)

# 2. Read only those lines
# Read(src/utils/jwt.ts, offset=7, limit=12)
# ~48 tokens vs ~1,200 for the full file

Auto-updating CLAUDE.md

crg-lean setup installs three git hooks that keep CLAUDE.md current:

• post-commit — after every local commit
• post-merge — after every git pull (picks up changes from other machines)
• post-rebase — after every rebase

The hooks only update the <!-- arch:start --> ... <!-- arch:end --> block. Human-written content below <!-- preserved-below --> is never touched.

Works in monorepos — each service can have its own CLAUDE.md and the hooks update all of them.

Claude Code skill

crg-lean ships as a Claude Code skill. Install it globally:

mkdir -p ~/.claude/skills/crg-lean
cp skills/crg-lean/SKILL.md ~/.claude/skills/crg-lean/SKILL.md

This tells Claude when and how to use crg-lean automatically, without being prompted.

How it works

crg-lean starts the code-review-graph serve MCP server as a subprocess, calls tools via JSON-RPC, then post-processes responses:

• Strips absolute paths → relative paths
• Removes fat fields: affected_flows, review_priorities, edges, impacted_nodes, context
• Limits arrays to top N
• Returns plain text instead of JSON

The MCP server is started fresh per invocation (~0.5s). No persistent daemon.