mapping-codebases

name	mapping-codebases
description	Generate navigable code maps for unfamiliar codebases. Extracts exports/imports via AST (tree-sitter) to create _MAP.md files per directory showing classes, functions, methods with signatures and line numbers. Use when exploring repositories, understanding project structure, analyzing unfamiliar code, or before modifications. Triggers on "map this codebase", "explore repo", "understand structure", "what does this project contain", or when starting work on an unfamiliar repository.
metadata	{"version":"0.7.1"}

Mapping Codebases

Generate _MAP.md files providing hierarchical code structure views. Maps show function signatures, class methods, imports, and line numbers—enabling API understanding without reading full source files.

Installation

uv venv /home/claude/.venv
uv pip install tree-sitter-language-pack --python /home/claude/.venv/bin/python

Bundled parsers: The skill includes pre-built parsers for all 10 supported languages (Python, JavaScript, TypeScript, TSX, Go, Rust, Ruby, Java, HTML, Markdown) in parsers/. These are used automatically when the tree-sitter-language-pack runtime download fails (e.g., in proxied environments). No network access needed for supported languages.

Generate Maps

/home/claude/.venv/bin/python /mnt/skills/user/mapping-codebases/scripts/codemap.py /path/to/repo --skip tests,.github,locale

Common skip patterns: tests,.github,.husky,locale,migrations,__snapshots__,coverage,target,docs

Navigate Via Maps

After generating maps, use them for navigation—read _MAP.md files, not source files directly.

Workflow:

1. Read root _MAP.md for high-level structure
2. Follow subdirectory links to drill into relevant areas
3. Use function signatures and class methods to understand APIs
4. Read full source only when implementation details are needed

Maps reveal without reading source:

• All public functions with signatures: def record_attempt(subtask_id, session, success, approach, error=None) :200
• Class structure with methods: RecoveryManager → classify_failure(), is_circular_fix(), rollback_to_commit()
• Import relationships showing module dependencies
• Line numbers for direct navigation

Anti-pattern: Reading files directory-by-directory. Use maps to find what you need, then read only the specific file/lines required.

Map Contents

Each _MAP.md includes:

• Directory statistics (file/subdirectory counts)
• Subdirectory links for hierarchical navigation
• Per-file: imports preview, symbol hierarchy with (C)lass/(m)ethod/(f)unction markers
• Function signatures (Python, TypeScript, Go, Rust, Ruby)
• Line numbers (:42 format) for every symbol
• Markdown files: h1/h2 heading ToC
• Other files section (JSON, YAML, configs)

Example:

# services/
*Files: 4 | Subdirectories: 0*

## Files

### recovery.py
> Imports: `json, subprocess, dataclasses, datetime, enum`...
- **FailureType** (C) :24
- **RecoveryManager** (C) :43
  - **__init__** (m) `(self, spec_dir: Path, project_dir: Path)` :55
  - **classify_failure** (m) `(self, error: str, subtask_id: str)` :137
  - **record_attempt** (m) `(subtask_id, session, success, approach, error=None)` :200
  - **is_circular_fix** (m) `(self, subtask_id: str, current_approach: str)` :242
  - **get_recovery_hints** (m) `(self, subtask_id: str)` :495

Commands

# Generate maps
/home/claude/.venv/bin/python /mnt/skills/user/mapping-codebases/scripts/codemap.py /path/to/repo

# Skip directories
/home/claude/.venv/bin/python /mnt/skills/user/mapping-codebases/scripts/codemap.py /path/to/repo --skip tests,.github

# Clean maps
/home/claude/.venv/bin/python /mnt/skills/user/mapping-codebases/scripts/codemap.py /path/to/repo --clean

# Dry run
/home/claude/.venv/bin/python /mnt/skills/user/mapping-codebases/scripts/codemap.py /path/to/repo -n

# Verbose (debug output)
/home/claude/.venv/bin/python /mnt/skills/user/mapping-codebases/scripts/codemap.py /path/to/repo -v

Default skips: .git, node_modules, __pycache__, .venv, venv, dist, build, .next

Supported Languages

Python, JavaScript, TypeScript, TSX, Go, Rust, Ruby, Java, HTML, Markdown.

Limitations

• Structural info only (symbols/imports), not semantic descriptions
• Signatures: Python (full), TypeScript/Go/Rust/Ruby (params + return types), Java (not extracted)
• Markdown: h1/h2 headings only
• Private symbols (_prefix) excluded from top-level exports