Setup LSP

import { Steps, Aside, Tabs, TabItem } from ‘@astrojs/starlight/components’;

kag-lsp is a Language Server Protocol implementation for KAG scripts (.ks files). It provides:

Syntax highlighting and error diagnostics
Hover documentation for every built-in tag and attribute
Go-to-definition for labels, macros, and files
Auto-completion for tag names and attribute keys
Find-all-references for labels and macros

Build from source

kag-lsp lives in the kag-lsp crate of this repository.

Clone the repository

git clone https://github.com/haruki-nikaidou/kani-engine.git
cd kani-engine

Build in release mode
Terminal window
```
cargo build -p kag-lsp --release
```
The binary is placed at target/release/kag-lsp.

Put it on your PATH

# Linux / macOS
cp target/release/kag-lsp ~/.local/bin/

# Or add the release dir to PATH in your shell profile
export PATH="$PATH:/path/to/kani-engine/target/release"

Editor setup

Install the KAG Script extension (or any generic LSP client such as vscode-glspc).

Add this to your settings.json:

{
  "languageServerExample.serverPath": "/path/to/kag-lsp"
}

Or, with a generic client:

{
  "genericLSP.servers": [
    {
      "name": "KAG",
      "language": "kag",
      "extensions": [".ks"],
      "command": ["kag-lsp"]
    }
  ]
}

Add to your Neovim config:

local lspconfig = require('lspconfig')
local configs = require('lspconfig.configs')

if not configs.kag_lsp then
  configs.kag_lsp = {
    default_config = {
      cmd = { 'kag-lsp' },
      filetypes = { 'kag' },
      root_dir = lspconfig.util.root_pattern('Cargo.toml', '.git'),
      settings = {},
    },
  }
end

lspconfig.kag_lsp.setup {}

Then add a filetype detection rule:

autocmd BufRead,BufNewFile *.ks set filetype=kag

Add to ~/.config/helix/languages.toml:

[[language]]
name = "kag"
scope = "source.kag"
file-types = ["ks"]
language-servers = ["kag-lsp"]

[language-server.kag-lsp]
command = "kag-lsp"

Any editor that supports the LSP protocol can use kag-lsp. Configure your editor to:

Launch kag-lsp as a server process (communicates over stdio)
Associate the .ks file extension with the kag language ID

Features overview

Hover documentation

Hovering over a tag name displays its description, required and optional attributes, and a short example — sourced directly from the tag_defs module.

Go-to-definition

Ctrl+click (or your editor’s equivalent) on a target=*label value jumps to the label’s definition, even across files.

Diagnostics

The LSP validates attribute completeness in real time:

Severity	Condition
Error	A required attribute (e.g. `storage=` on `[bg]`) is missing
Warning	A recommended attribute is absent and the tag will have no effect

Completion

Pressing the completion key inside [ or after a space inside a tag gives you:

All known tag names
All valid attribute keys for the current tag
Boolean value suggestions (true / false)