iii Language Server - VS Code Extension

Autocompletion, hover documentation, and diagnostics for iii engine functions and triggers.

Supported Languages

• TypeScript / TSX
• Python
• Rust

Prerequisites

1. iii-lsp binary - The extension downloads and installs the pinned iii-lsp/v0.1.0 binary on first activation.

   The binary is stored under VS Code's extension global storage directory and the absolute path is saved to iii-lsp.serverPath in global settings.

   To use a custom binary instead, set iii-lsp.serverPath to an existing executable path before activation.

2. iii engine running locally (default: ws://127.0.0.1:49134)

Installation

After the extension is installed, open a supported TypeScript, TSX, Python, or Rust file to activate it. On first activation, the extension downloads the matching iii-lsp/v0.1.0 binary, verifies its SHA-256 checksum, installs it under extension global storage, and saves the installed path to iii-lsp.serverPath.

If automatic install fails, the extension warns and falls back to the configured iii-lsp.serverPath or iii-lsp on PATH.

From source (development)

1. Install dependencies:

   cd iii-lsp-vscode
   npm install
   

2. Open VS Code and install the extension locally:

   # From the repo root
   code --install-extension iii-lsp-vscode
   

   Or, in VS Code:

   • Open the Command Palette (Cmd+Shift+P)
   • Run Extensions: Install from Location...
   • Select the iii-lsp-vscode directory

From VSIX package

1. Package the extension:

   cd iii-lsp-vscode
   npm install
   npx @vscode/vsce package
   

2. Install the .vsix file:

   code --install-extension iii-lsp-*.vsix
   

Local smoke test with Cursor

Build a local VSIX and install it in Cursor:

cd iii-lsp-vscode
make build
cursor --install-extension iii-lsp.vsix --force

Open a supported file to activate the extension:

cursor ../iii-lsp/src/main.rs

After activation, iii-lsp.serverPath should point to the downloaded binary in Cursor settings. To install the same VSIX in VS Code instead, replace cursor with code.

Settings

Configure via Settings > search "iii LSP", or in settings.json:

{
  "iii-lsp.serverPath": "/path/to/iii-lsp",
  "iii-lsp.engineUrl": "ws://127.0.0.1:49134"
}

Features

• Completions - Function IDs, trigger types, payload properties, trigger config properties, and known values (stream names, topics, API paths)
• Hover - Function documentation with request/response JSON schemas
• Diagnostics - Validates function IDs, required payload fields, trigger types, config properties, cron expressions, and HTTP methods