Supported Languages — 17 Languages via AST & Tree-sitter

vfs supports 17 languages using a combination of Go’s native AST parser, tree-sitter grammars, and line-based heuristics.

Language table

Language	Extensions	Parser
Go	.go	go/ast
JavaScript	.js, .mjs, .cjs, .jsx	tree-sitter
TypeScript	.ts, .mts, .cts, .tsx	tree-sitter
Python	.py	tree-sitter
Rust	.rs	tree-sitter
Java	.java	tree-sitter
C#	.cs	tree-sitter
Dart	.dart	tree-sitter
Kotlin	.kt, .kts	tree-sitter
Swift	.swift	tree-sitter
Ruby	.rb	tree-sitter
Solidity	.sol	tree-sitter
HCL / Terraform	.tf, .hcl	tree-sitter
Dockerfile	Dockerfile, Dockerfile.*	line-based
Protobuf	.proto	line-based
SQL	.sql	line-based
YAML	.yml, .yaml	line-based

Parser types

Go AST (go/ast)

Go files are parsed using Go’s built-in go/ast package. This provides the most accurate extraction since it uses the same parser as the Go compiler.

Tree-sitter

JavaScript, TypeScript, Python, Rust, Java, C#, Dart, Kotlin, Swift, Ruby, Solidity, and HCL / Terraform are parsed using tree-sitter grammars. Tree-sitter produces concrete syntax trees that vfs traverses to extract exported declarations.

Line-based

Dockerfiles, Protobuf, SQL, and YAML use pattern-based heuristics. These formats have simple enough structure that AST parsing is unnecessary.

What gets extracted

vfs extracts exported signatures — the public API surface of your code:

• Functions and methods (exported/public)
• Classes and interfaces
• Type declarations (structs, enums, type aliases)
• Constants and variables (exported)

Function bodies, imports, and comments are stripped from the output.

Unsupported languages

For languages not in the table above, use grep or rg directly. You can check at any time with:

vfs mcp
# Then call the list_languages MCP tool