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Tree Sitting Skill for Claude

AST-powered code navigation via tree-sitter. Auto-scans codebases and provides progressive-disclosure tree views with symbol search, source retrieval, and reference finding. Each invocation is self-contained — no cross-process state. Use when exploring unfamiliar repos, navigating code, or needing fast symbol lookup. Triggers on "map this codebase", "explore repo", "find symbol", "navigate code", "tree-sitter", or when starting work on an unfamiliar repository.

54k tokens
context cost
the whole folder, loaded on every use
12
files
ships runnable scripts
0
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 tree-sitting

The instruction itself

13 sections, as written by the author

tree-sitting

AST-powered code navigation using tree-sitter. Each invocation auto-scans

the codebase (~700ms for 250 files), then runs queries at sub-millisecond speed.

Setup

uv pip install --system --break-system-packages tree-sitter

Grammars are loaded from bundled parsers/*.so files — no network fetch,

no tree-sitter-language-pack dependency. Install is <1s.

Usage: CLI (treesit.py)

Every call auto-scans, prints a tree overview, then runs any queries.

No state to manage between calls.

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

# Orient: root-level overview (default depth=1)
python3 $TREESIT /path/to/repo

# Featuring: complete tree, minimal detail
python3 $TREESIT /path/to/repo --depth=-1 --detail=sparse

# Explore a subdirectory in full detail
python3 $TREESIT /path/to/repo --path=src/core --detail=full

# Run queries (tree overview + query results)
python3 $TREESIT /path/to/repo 'find:Parser*' 'source:parse_input'

# Queries only, no tree
python3 $TREESIT /path/to/repo --no-tree 'refs:AuthToken'

Options

| Option | Default | Description |

|--------|---------|-------------|

| --depth N | 1 | Directory depth: -1=all, 0=root only, 1=one level |

| --detail LEVEL | normal | Node detail: sparse, normal, full |

| --path DIR | (root) | Scope to subdirectory |

| --skip DIRS | | Extra dirs to skip (comma-separated) |

| --no-tree | | Suppress tree overview, show only queries |

| --stats | | Show scan timing and counts |

Detail Levels

All levels include line ranges (:start-end) so you can feed the

window straight into Read --offset/--limit without another scan.

| Level | Tree-overview row (per file) | Use case |

|-------|------------------------------|----------|

| sparse | file: name:1-10, Other:30-90 +3 | featuring: see the full shape |

| normal | file: name(f):1-10, Other(c):30-90 +3 | exploring: quick orientation |

| full | full per-symbol formatter + children + imports | exploring: deep dive into a directory |

Queries

Append after the repo path. Multiple queries per call.

| Query | Example | Description |

|-------|---------|-------------|

| find:PATTERN[:KIND[:LIMIT]] | find:*Handler*:function | Symbol search (glob/substring) |

| symbols:FILE | symbols:src/api.py | All symbols in a file |

| source:SYMBOL[:FILE] | source:parse_input | Source code of a symbol |

| refs:SYMBOL[:LIMIT] | refs:AuthToken:30 | Text references across codebase |

| imports:FILE | imports:src/api.py | Import list for a file |

| dir:PATH | dir:src/core | Directory overview (engine format) |

Caching

Scans are cached to disk, keyed on a fileset fingerprint (mtime + size of all

files under root, combined with skip-set and cache format version). Repeat drills

in a session skip re-parsing — results are byte-identical whether served from

cache or fresh parse.

Cache auto-invalidates when files change, are added, or removed. Use --no-cache

to skip cache entirely (always parse), or --rebuild-cache to ignore existing

cache and rewrite it. Set TREESIT_CACHE_DIR environment variable to relocate

cache from the system temp directory.

Workflow

For structural drills ("what does this expose", "where is X", "who calls X"),

batch multiple queries in a single call:

# Batch drills (default for exploration)
treesit.py /repo 'find:Parser*' 'source:parse_input' 'refs:ParseState'

One scan, all results. Do not fall back to grep or sed for symbol lookups —

the AST queries (find:, source:, refs:) provide accurate, fast symbol-aware

results that text search cannot match.

For iterative exploration:

1. treesit.py /repo                           → orient: what dirs, how big
2. treesit.py /repo --path=src/core           → drill into interesting directory
3. treesit.py /repo 'find:Parser*'            → find specific symbols
4. treesit.py /repo 'source:parse_input'      → read implementation
5. treesit.py /repo 'refs:ParseState'         → find usage across codebase

Each call is self-contained. No need to "scan first, query later" —

scan happens automatically, and results are cached for subsequent calls (~700ms first scan).

Usage: Direct Python (single invocation)

For custom scripts that need the engine API directly:

import sys; sys.path.insert(0, '/mnt/skills/user/tree-sitting/scripts')
from engine import CodeCache

cache = CodeCache()
cache.scan('/path/to/repo')
# All queries in the SAME invocation:
print(cache.tree_overview())
print(cache.find_symbol('ClassName'))
print(cache.get_source_range('src/core/parser.c', 100, 150))

Important: The cache is in-memory only. All scan + query calls MUST

happen in the same Python process. Splitting across separate python -c

invocations loses the cache — use treesit.py instead.

Supported Languages

Bundled grammars (work out of the box):

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

Three-tier extraction for bundled languages:

  • Custom extractors (richest — signatures, hierarchy, docstrings): Python, C, Go, Rust, JavaScript, TypeScript, TSX, Ruby, Markdown (heading outline)
  • tags.scm queries (community-maintained — kinds, docs): Java, Mojo
  • Generic heuristic (names + kinds + locations): HTML and any future bundled grammars

Adding a grammar

Files with unsupported extensions are silently skipped (they show as SKIP (no parser) with --stats). To add a grammar, drop a compiled libtree_sitter_<lang>.so into parsers/ — the engine picks it up automatically on the next run. Build from the grammar's repo (each tree-sitter/tree-sitter-<lang> repo has a src/ directory you can compile with cc -shared -fPIC -I src src/parser.c src/scanner.c -o libtree_sitter_<lang>.so, or use tree-sitter build).

If you need a language urgently and can't build the .so, you can try installing tree-sitter-language-pack as a fallback (uv pip install --system --break-system-packages 'tree-sitter-language-pack<1.6.3') — but note 1.6.3 ships a broken wheel (only _native/, missing the tree_sitter_language_pack/ python module → ModuleNotFoundError despite pip showing it installed); 1.6.2 and earlier work, hence the <1.6.3 pin and try to download grammars at runtime from a domain that may not be in your network allowlist. Bundling the .so is the reliable path.

What It Extracts

  • Symbols: functions, classes, structs, enums, methods, constants, defines, types
  • Signatures: parameter lists and return types (Python, C; partial for others)
  • Doc comments: first-line summaries from docstrings, JSDoc, Doxygen, ///, #
  • Line ranges: start and end line for every symbol
  • Imports: per-file dependency tracking
  • Hierarchy: class→methods, struct→fields (Python, C)

Architecture

CodeCache (in-memory, per-invocation)
  ├── files: {relpath → FileEntry(source, tree, symbols, imports)}
  ├── _symbol_index: {name → [Symbol, ...]}  ← fast lookup
  └── methods: scan(), find_symbol(), file_symbols(), dir_overview(), ...
       │
       └── treesit.py CLI — auto-scan + progressive-disclosure tree + queries

Parse cost is paid once per invocation. The symbol index enables O(1) exact

match and O(n) substring/glob search where n is the number of unique symbol

names (not files).

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How to use it

Copy the folder

Take oaustegard/tree-sitting 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.

Install what it needs

The instructions reference pip, uv. Without those the skill loads but fails at the first command.