extract-rules

# Extract Rules

Analyzes existing codebase to extract project-specific coding rules and domain knowledge, generating structured markdown documentation for AI agents.

## Usage

```text
/extract-rules                      # Extract rules from codebase (initial)
/extract-rules --update             # Re-scan and add new patterns (preserve existing)
/extract-rules --force              # Overwrite all rule files (discard existing)
/extract-rules --from-conversation  # Extract rules from conversation and append
```

## Configuration

Users can configure extraction settings in `extract-rules.local.md`:

- Project-level: `.claude/extract-rules.local.md` (takes precedence)
- User-level: `~/.claude/extract-rules.local.md`

**File format:** YAML frontmatter only (no markdown body). The file uses `.md` extension for consistency with other Claude Code config files, but contains only YAML between `---` delimiters.

```yaml
---
# Target directories for analysis
# Default: "." (all directories not excluded by .gitignore)
# Set specific directories to limit scope
target_dirs:
  - .

# Directories to exclude (in addition to .gitignore)
# These are applied even if not in .gitignore
exclude_dirs:
  - .git
  - .claude

# File patterns to exclude (in addition to .gitignore)
exclude_patterns:
  - "*.generated.ts"
  - "*.d.ts"
  - "*.min.js"

# Note: .gitignore patterns are automatically applied
# Common exclusions like node_modules/, dist/, build/ are typically in .gitignore

# Output directory
output_dir: .claude/rules

# Output language for reports
language: ja
---
```

## Output Structure

```text
.claude/rules/
├── languages/
│   ├── typescript.md
│   └── ...              # python.md, go.md, ruby.md, etc.
├── frameworks/
│   ├── react.md
│   └── ...              # nextjs.md, firebase.md, rails.md, etc.
└── project.md           # Domain, architecture (not portable)
```

## Processing Flow

### Mode Detection

Check arguments to determine mode:

- No arguments or `--force` → **Full Ext