Agent-Skills.md

Agent Skills: Mapping Codebases

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.

UncategorizedID: oaustegard/claude-skills/mapping-codebases

Repository

oaustegard/claude-skills
oaustegardLicense: MIT
953

Install this agent skill to your local

pnpm dlx add-skill https://github.com/oaustegard/claude-skills/tree/HEAD/mapping-codebases

Skill Files

Browse the full folder contents for mapping-codebases.

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mapping-codebases/SKILL.md

Skill Metadata

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.

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 11 supported languages (Python, JavaScript, TypeScript, TSX, Go, Rust, Ruby, Java, C, 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, C)
  • Line ranges (:42-85 format) showing symbol start and end lines
  • Doc comments — first-line summaries from docstrings, JSDoc, Doxygen, ///, # comments
  • Constants and defines (pub const, #define, export const, Go const)
  • Enum variants as children of enum symbols (C)
  • 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) :24-38
- **RecoveryManager** (C) :43-510 — Manages error recovery strategies.
  - **__init__** (m) `(self, spec_dir: Path, project_dir: Path)` :55-72
  - **classify_failure** (m) `(self, error: str, subtask_id: str)` :137-198 — Classify an error into a FailureType.
  - **record_attempt** (m) `(subtask_id, session, success, approach, error=None)` :200-240
  - **is_circular_fix** (m) `(self, subtask_id: str, current_approach: str)` :242-280
  - **get_recovery_hints** (m) `(self, subtask_id: str)` :495-510

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, C, HTML, Markdown.

Limitations

  • Doc comments extracted as first-line summaries (not full descriptions)
  • Signatures: Python (full), TypeScript/Go/Rust/Ruby/C (params + return types), Java (not extracted)
  • Markdown: h1/h2 headings only
  • Private symbols (_prefix) excluded from top-level exports