---
name: "ast-grep Structural Code Search and Rewrite"
slug: "ast-grep-structural-code-search-rewrite"
description: "Use ast-grep (sg) to search, lint, and rewrite code across large codebases using AST pattern matching. A blazing-fast alternative to regex-based code transformations that understands syntax structure."
github_stars: 13245
verification: "security_reviewed"
source: "https://github.com/ast-grep/ast-grep"
category: "Code Quality & Review"
framework: "Claude Code"
tool_ecosystem:
  github_repo: "ast-grep/ast-grep"
  github_stars: 13245
---

# ast-grep Structural Code Search and Rewrite

Use ast-grep (sg) to search, lint, and rewrite code across large codebases using AST pattern matching. A blazing-fast alternative to regex-based code transformations that understands syntax structure.

## Installation

Use the upstream install or setup path that matches your environment:
- npm install --global @ast-grep/cli
- pip install ast-grep-cli
- brew install ast-grep
- cargo install ast-grep --locked

Requirements and caveats from upstream:
- You can use $ sign + upper case letters as a [wildcard](https://en.wikipedia.org/wiki/Wildcard_character), e.g. $MATCH, to match any single AST node. Think of it as [regular expression dot](https://regexone.com/lesson...
- You can install it from [npm](https://docs.npmjs.com/downloading-and-installing-node-js-and-npm), [pip](https://pypi.org/), [cargo](https://doc.rust-lang.org/cargo/getting-started/installation.html), [cargo-binstall](...

Basic usage or getting-started notes:
- bash
- # pnpm approve-builds may be needed
- <details>

- Source: https://github.com/ast-grep/ast-grep
- Extracted from upstream docs: https://raw.githubusercontent.com/ast-grep/ast-grep/HEAD/README.md

## Source

- [Agent Skill Exchange](https://agentskillexchange.com/skills/ast-grep-structural-code-search-rewrite/)