ast-grep MCP Server

What it does

This MCP server provides a powerful interface for structural code search and manipulation using ast-grep. It allows AI assistants to perform pattern-based searches, safe code rewrites, complexity analysis, and automated deduplication across multi-language codebases.

Tools

• find_code: Structural search using patterns or YAML rules.
• rewrite_code: Safe code transformations with backup and rollback.
• extract_function: Scope-aware function extraction with parameter detection.
• find_duplication: Detection of code duplicates using MinHash/LSH.
• analyze_complexity: Metrics for cyclomatic and cognitive complexity.
• detect_code_smells: Identification of common anti-patterns and smells.
• create_linting_rule: Define and apply custom linting templates.
• generate_docstrings: Automated documentation for functions and classes.

Installation

Add the following to your claude_desktop_config.json:

{
  "mcpServers": {
    "ast-grep": {
      "command": "uv",
      "args": ["--directory", "/absolute/path/to/ast-grep-mcp", "run", "main.py"]
    }
  }
}

Supported hosts

• Claude Desktop