| name | ast-grep |
| description | Structural code search and rewrite via the bundled ast_grep MCP server. Use for AST patterns ($VAR, $$$), not regex. Prefer over Grep when matching syntax trees.
|
| user_invocable | false |
AST-Grep (MCP ast_grep)
Bundled server: node ${GROK_PLUGIN_ROOT}/vendor/ast-grep-mcp/dist/cli.js mcp
When to use
- Find or rewrite syntax-shaped code (functions, imports, classes, control flow)
- Refactors that must respect language grammar (25 languages)
When not to use
- Plain text, alternation (
foo|bar), or regex wildcards → use Grep / rg instead
Tools (via CallMcpTool, server ast_grep)
| Tool | Purpose |
|---|
search | AST pattern search (pattern, lang, optional paths, globs, context) |
replace | AST rewrite (pattern, rewrite, lang; dryRun defaults to true) |
Pattern syntax
$VAR — one AST node (identifier, expression, statement, …)$$$ — zero or more nodes (args, bodies, …)- Patterns must be valid source for the chosen
lang
Examples:
- TypeScript:
function $NAME($$$) { $$$ }, console.log($$$)
- Python:
def $FUNC($$$), class $C($$$) (no trailing colon in pattern)
- Go:
func $NAME($$$) { $$$ }
Workflow
- Search with a concrete pattern; narrow
paths / globs if noisy.
- Replace with
dryRun: true first; review preview; then dryRun: false.
- After edits, run LSP diagnostics on touched files (see
skills/lsp).
Aliases
Some hosts expose the same tools as ast_grep_search / ast_grep_replace.
