ast-grep-skill

name	ast-grep-skill
description	Structural code search, linting, and rewriting using AST-level pattern matching. Use when users need to search code by syntax structure (not text), write custom lint rules, perform codemods across a codebase, replace regex grep for precise AST-aware queries, or create reusable lint rule sets. Covers CLI usage, pattern syntax, rule system (atomic/relational/composite/utility), lint rule authoring, rewrite/transform, project setup, and testing.
version	0.1.0
ast-grep_version	>=0.43.0
last_updated	"2026-06-21T00:00:00.000Z"

ast-grep

Overview

ast-grep searches and transforms code using AST patterns instead of text regex. Think grep × eslint × codemod — but polyglot, with a single pattern language across 20+ languages via tree-sitter.

Powered by Rust. Handles 10k+ files in seconds. Supports search, lint, rewrite, and programmatic API usage.

Supported Languages

Domain	Languages
System	C, C++, Rust
Server	Go, Java, Python, C#
Web	JS(X), TS(X), HTML, CSS
Mobile	Kotlin, Swift
Config	JSON, YAML, HCL
Scripting	Lua, Nix

First Search

# Find all console.log calls
ast-grep -p 'console.log($$$)' -l ts

# Find with rewite
ast-grep -p '$PROP && $PROP()' -r '$PROP?.()' -l ts

# Interactive mode
ast-grep -p 'var $NAME = $VAL' -r 'const $NAME = $VAL' --interactive

Always single-quote patterns to prevent shell expansion of $.

Reference Files

The skill is split into focused reference files for easier navigation:

File	Covers
references/cli-usage.md	CLI commands, flags, JSON output, stdin, completions
references/pattern-syntax.md	Meta variables, capturing, anonymous patterns, matching strictness
references/rules-overview.md	Rule essentials, atomic rules (pattern, kind, regex, nthChild, range)
references/relational-rules.md	Relational rules (inside, has, follows, precedes), composite rules (all, any, not, matches), ESQuery selectors
references/lint-rules.md	Lint rule structure, severity, files/ignores, labels, inline suppression
references/rewrite-transform.md	fix, transform operators (9 types), FixConfig, rewriters
references/project-setup.md	sgconfig.yml, CI/CD, advanced config
references/testing.md	Test file structure, running tests
references/common-patterns.md	Quick one-liner patterns
references/editor-integration.md	VS Code, Neovim, Astra TUI
references/catalog-index.md	Ready-to-use rule templates index
references/troubleshooting.md	FAQ, common issues and solutions
references/api-usage.md	JS (napi), Python, Rust API usage
references/rule_reference.md	Full rule grammar reference
references/transform-operators.md	Complete transform operator reference
references/catalog/	Ready-to-use rule YAML files (7 patterns)