Editor Setup

mashin provides editor extensions for VS Code and Zed, plus a tree-sitter grammar that works with any editor that supports tree-sitter.

VS Code

The VS Code extension provides syntax highlighting, completions, hover documentation, go-to-definition, formatting, and diagnostics.

Installation

Install from the marketplace (search “mashin”) or install locally for development:

# Symlink the extension into your VS Code extensions directory
ln -s /path/to/mashin-core/tools/mashin-vscode ~/.vscode/extensions/mashin-language

Restart VS Code. Open any .mashin file to verify syntax highlighting.

Features

Feature	What it does
Syntax highlighting	Full mashinTalk grammar (TextMate)
Completions	Keywords, step types, @mashin/actions/* machines, config options
Hover	Documentation for keywords, step types, stdlib machines, context accessors
Go-to-definition	Navigate to stdlib machines, local machines, steps, input fields
Formatting	Format via the mashin language server
Diagnostics	Real-time validation of machine structure and syntax
Snippets	25+ templates for machines, steps, goals, and common patterns

Snippets

Type these prefixes and press Tab:

Prefix	Creates
machine	New machine skeleton
step-reason	LLM reasoning step
step-code	Pure computation step
step-call	Call an effect machine
step-memory	Memory operation step
inputs	Input schema block
outputs	Output schema block
goal	Goal specification
call-http-get	Call @mashin/actions/http/get
call-http-post	Call @mashin/actions/http/post
permissions	Permission policies
hooks	Step hooks/middleware

Enabling the language server

For full LSP features (completions, diagnostics, formatting), build the language server and configure VS Code to use it:

# From the mashin-core project root
mix escript.build --app mashin_language_server

The extension will detect the language server automatically if it is in your PATH as mashin-language-server, or you can configure the path in VS Code settings.

Zed

The Zed extension uses the tree-sitter grammar for syntax highlighting and connects to the language server for completions, hover, and diagnostics.

Installation

In Zed, open the Extensions panel (Cmd+Shift+X), select “Install Dev Extension…”, and point it at the tools/mashin-zed/ directory.

Enabling the language server

Add to your Zed settings (~/.config/zed/settings.json):

{
  "lsp": {
    "mashin-language-server": {
      "binary": {
        "path": "/path/to/mashin-core/mashin_language_server",
        "arguments": ["--stdio"]
      }
    }
  }
}

Tree-sitter grammar

The tree-sitter grammar is the canonical definition of mashinTalk syntax. Any editor with tree-sitter support can use it.

The grammar lives at tools/tree-sitter-mashin-talk/grammar.js. It handles the full mashinTalk keyword-hierarchy syntax including:

• Machine declarations and all section types
• Step types (compute, ask, decide, for_each, etc.)
• Expressions (arithmetic, string interpolation, arrow functions, match expressions)
• Comments (line and block)

Using with other editors

For editors like Neovim, Helix, or Emacs (with tree-sitter support):

1. Clone or link the tools/tree-sitter-mashin-talk/ directory
2. Build the parser: cd tools/tree-sitter-mashin-talk && tree-sitter generate && tree-sitter build
3. Configure your editor to use the grammar for .mashin files
4. Copy the highlight queries from tools/tree-sitter-mashin-talk/queries/ into your editor’s query directory

Next steps

• Language Server - Full LSP feature reference
• CLI Reference - The command-line tool