How do I install the Ast Grep skill?

Run npx skillmds@latest add tomevault-io/ast-grep-2 in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Ast Grep safe to use?

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Which AI agents work with Ast Grep?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Ast Grep free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Ast Grep?

tomevault-io (@tomevault-io) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Ast Grep by tomevault-io — Agent Skill

Name: Ast Grep
Author: tomevault-io

Ast Grep

AST-based code search and transformation tool using tree-sitter. Use for structural pattern matching, refactoring deprecated APIs, detecting anti-patterns, migrating code between library versions, and enforcing coding standards. Use when this capability is needed.

tomevault-io Updated Sep 17, 2026

File contents

ast-grep - AST-based Code Search and Transformation

ast-grep is an AST-based tool for searching, linting, and refactoring code across multiple languages. It uses tree-sitter to parse code into Abstract Syntax Trees, enabling precise structural pattern matching.

Key Pattern Syntax

$META - Matches a single AST node (e.g., $VAR, $FUNC, $ARG)
$$$ - Matches zero or more AST nodes (useful for function arguments, statements)
$_ - Non-capturing metavariable (matches but doesn't capture)
Patterns must be syntactically valid code in the target language

Triggers

AST pattern, structural search, code refactoring, find anti-patterns, migrate code, console.log, deprecated API, function definition, class search, method signature, unused variables, security vulnerabilities, code transformation, pattern matching

When to Use

Finding specific code patterns across large codebases
Refactoring code (replacing deprecated APIs, updating syntax)
Detecting anti-patterns or potential bugs
Migrating between library versions
Enforcing coding standards
Interactive code rewriting

Examples

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---name: ast-grep-2description: AST-based code search and transformation tool using tree-sitter. Use for structural pattern matching, refactoring deprecated APIs, detecting anti-patterns, migrating code between library versions, and enforcing coding standards. Use when this capability is needed.---# ast-grep - AST-based Code Search and Transformationast-grep is an AST-based tool for searching, linting, and refactoring code across multiple languages. It uses tree-sitter to parse code into Abstract Syntax Trees, enabling precise structural pattern matching.## Key Pattern Syntax- `$META` - Matches a single AST node (e.g., `$VAR`, `$FUNC`, `$ARG`)- `$$$` - Matches zero or more AST nodes (useful for function arguments, statements)- `$_` - Non-capturing metavariable (matches but doesn't capture)- Patterns must be syntactically valid code in the target language## TriggersAST pattern, structural search, code refactoring, find anti-patterns, migrate code, console.log, deprecated API, function definition, class search, method signature, unused variables, security vulnerabilities, code transformation, pattern matching## When to Use- Finding specific code patterns across large codebases- Refactoring code (replacing deprecated APIs, updating syntax)- Detecting anti-patterns or potential bugs- Migrating between library versions- Enforcing coding standards- Interactive code rewriting## Examples<examples> <example> <user>I need to find all React components using useState</user> <agent>I'll find useState usage in React components: `ast-grep --pattern 'const [$STATE, $SETTER] = useState($$$)'`</agent> </example> <example> <user>Replace && chains with optional chaining for null checks</user> <agent>I'll modernize null checks to optional chaining: `ast-grep --pattern '$OBJ && $OBJ.$PROP' --rewrite '$OBJ?.$PROP' --interactive`</agent> </example> <example> <user>Find async functions that don't have error handling</user> <agent>I'll search for async functions without try-catch: `ast-grep --pattern 'async function $NAME($$$PARAMS) { $$$BODY }' | grep -v try`</agent> </example> <example> <user>Find all TypeScript interfaces</user> <agent>I'll search for TypeScript interfaces: `ast-grep --pattern 'interface $NAME { $$$BODY }' --lang ts`</agent> </example> <example> <user>I want to find potential null pointer exceptions</user> <agent>I'll search for property access without null checks: `ast-grep --pattern '$VAR.$PROP' --filter 'not match { $VAR?.$PROP }'`</agent> </example></examples>---> Converted and distributed by [TomeVault](https://tomevault.io/claim/natsukium) — claim your Tome and manage your conversions.

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