Mapping Codebases Skill for Claude

DEPRECATED — superseded by tree-sitting. This skill generated persistent _MAP.md files; tree-sitting does the same AST extraction at runtime (~700ms for 250 files) with no artifact to write, commit, or keep in sync. Use tree-sitting for "map this codebase", "explore repo", "understand structure", or any code navigation task. The final working version is archived at release mapping-codebases-v0.8.0.

1k tokens

context cost

the whole folder, loaded on every use

files

instructions only

copies elsewhere

how many repositories repackaged it

137

stars on the repo

on the repository, not the skill itself

Install

one command, takes just this skill from the repository

npx skills add https://github.com/oaustegard/claude-skills --skill mapping-codebases

The instruction itself

4 sections, as written by the author

Mapping Codebases (deprecated)

Use tree-sitting instead.

Why

This skill wrote _MAP.md files to disk — a persisted symbol inventory per

directory, generated once and read many times. That tradeoff made sense when

scanning was expensive. It isn't: tree-sitting parses a 250-file repo in about

700ms and answers queries against the in-memory AST in under a millisecond.

A persisted map costs what a runtime scan does not — it goes stale, it needs

regenerating, it gets committed, and it must be excluded from every other tool

that walks the tree. Nothing was gained for that.

Replacement commands

TREESIT=/mnt/skills/user/tree-sitting/scripts/treesit.py

# Was: codemap.py /path/to/repo          → root orientation
python3 $TREESIT /path/to/repo

# Was: reading every _MAP.md in the tree → full inventory
python3 $TREESIT /path/to/repo --depth=-1 --detail=sparse

# Was: grepping _MAP.md for a symbol     → direct lookup
python3 $TREESIT /path/to/repo --no-tree 'find:parse_input'

The archived version

The last working release is

mapping-codebases-v0.8.0

(2026-03-31). It carries scripts/codemap.py and the eleven bundled

parsers/*.so grammars. The release is the snapshot; nothing in this directory

reproduces it.

Note that v0.8.0 ships a latent bug: codemap.py:1216 calls an unimported

get_parser() inside a try swallowed by a bare except Exception, so HTML

inline-JavaScript symbol extraction silently returned nothing. It will not be

fixed.

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How to use it

Copy the folder

Take oaustegard/mapping-codebases from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.