SKILL.md
AST-Grep Find
Structural code search that understands syntax. Find patterns like function calls, imports, class definitions - not just text.
When to Use
- Find code patterns (ignores strings/comments)
- Search for function calls, class definitions, imports
- Refactor code with AST precision
- Rename variables/functions across codebase
Usage
Search for a pattern
uv run python -m runtime.harness scripts/ast_grep_find.py \
--pattern "import asyncio" --language python
Search in specific directory
uv run python -m runtime.harness scripts/ast_grep_find.py \
--pattern "async def \$FUNC(\$\$\$)" --language python --path "./src"
Refactor/replace pattern
uv run python -m runtime.harness scripts/ast_grep_find.py \
--pattern "console.log(\$MSG)" --replace "logger.info(\$MSG)" \
--language javascript
Dry run (preview changes)
uv run python -m runtime.harness scripts/ast_grep_find.py \
--pattern "print(\$X)" --replace "logger.info(\$X)" \
--language python --dry-run
Parameters
Parameter
Description
--pattern
AST pattern to search (required)
--language
Language: python, javascript, typescript, go, etc.
--path
Directory to search (default: .)
--glob
File glob pattern (e.g., **/*.py)
--replace
Replacement pattern for refactoring
--dry-run
Preview changes without applying
--context
Lines of context (default: 2)
Pattern Syntax
Syntax
Meaning
$NAME
Match single node (variable, expression)
$$$
Match multiple nodes (arguments, statements)
$_
Match any single node (wildcard)
Examples
# Find all function definitions
uv run python -m runtime.harness scripts/ast_grep_find.py \
--pattern "def \$FUNC(\$\$\$):" --language python
# Find console.log calls
uv run python -m runtime.harness scripts/ast_grep_find.py \
--pattern "console.log(\$\$\$)" --language javascript
# Replace print with logging
uv run python -m runtime.harness scripts/ast_grep_find.py \
--pattern "print(\$X)" --replace "logging.info(\$X)" \
--language python --dry-run
vs morph/warpgrep
Tool
Best For
ast-grep
Structural patterns (understands code syntax)
warpgrep
Fast text/regex search (20x faster grep)
Use ast-grep when you need syntax-aware matching. Use warpgrep for raw speed.
MCP Server Required
Requires ast-grep server in mcp_config.json.