lean-claude-md

Lean CLAUDE.md: Every Line Must Earn Its Place

Based on Boris Cherny's (Claude Code creator) workflow: ~100 lines that outperform 500-line files. The key: every rule exists because it solved a real problem.

Process

1. Read the CLAUDE.md at the path in $ARGUMENTS (default: ./CLAUDE.md)
2. For every line, ask: "If I remove this, would Claude make mistakes?"
   • If YES → keep it
   • If NO → mark for removal
3. Check for redundancy with Claude's defaults:
   • Claude already reads files before editing (don't need to say so)
   • Claude already uses git (don't need to explain git workflows)
   • Claude already follows language conventions (don't need to specify them)
   • Claude already writes tests (don't need generic test instructions)
4. Check for lines that should be hooks instead:
   • "Always run linter" → should be a PostToolUse hook
   • "Never force push" → should be a PreToolUse blocking hook
   • If it says "always" or "never", it might belong in a hook
5. Apply primacy/recency placement:
   • Most-violated rules at the TOP (first 5 lines)
   • Same critical rules at the BOTTOM (last 5 lines)
   • Less critical in the middle

Output

Present two versions:

1. Annotated original: Each line marked [KEEP], [REMOVE], or [→ HOOK]
2. Trimmed version: The lean CLAUDE.md with only the keepers

Ask before overwriting the original. Suggest saving the original as CLAUDE.md.backup first.

The 30-Line Test

If your trimmed version is still over 100 lines, you're probably including things Claude already does. Be more aggressive.