Semantic Web Language Server

IDE support for Semantic Web languages — Turtle, TriG, JSON-LD, and SPARQL. Autocompletion, diagnostics, formatting, SHACL validation, and more.

Features
Installation
- VS Code
- NeoVim
Configuration
Documentation
Screenshots

Features

Diagnostics

Syntax errors — immediate feedback on malformed documents
Undefined prefixes — flags uses of undeclared namespace prefixes
SHACL shape violations — validates data against loaded SHACL shapes

Completion

Prefix completion — typing foa expands to foaf: and inserts the prefix declaration
Property completion — suggests properties ordered by domain relevance
Class completion — when the predicate is a, suggests applicable classes

Hover

Shows labels, descriptions, and class information for IRIs

Rename

Rename terms local to the current file

Formatting

Format Turtle and JSON-LD documents

Semantic Highlighting

Full semantic token highlighting for all supported languages

Installation

VS Code

Install from the Visual Studio Marketplace or Open VSX Registry.

On startup the extension looks for a native swls binary in its own directory (set swls.command to use a custom path instead). If no binary is found it falls back to a bundled WASM worker so the LSP is available immediately without any extra setup.

In the background it checks GitHub releases for updates. When a newer version is available you will be prompted to install it; after the download completes a window reload switches to the native binary.

NeoVim

A NeoVim plugin is available at SemanticWebLanguageServer/swls.nvim.

Configuration

All settings live under the swls prefix.

Setting	Type	Default	Description
`swls.command`	string	`""`	Path to the swls binary. If empty, the bundled binary in the extension directory is used
`swls.turtle`	boolean	`true`	Enable Turtle language support
`swls.trig`	boolean	`true`	Enable TriG language support
`swls.jsonld`	boolean	`true`	Enable JSON-LD language support
`swls.sparql`	boolean	`false`	Enable SPARQL language support (experimental)
`swls.checkUpdate`	boolean	`true`	Check GitHub for new releases on startup
`swls.automaticUpdate`	boolean	`false`	Install updates without prompting
`swls.log`	string	`"debug"`	Log level: `error`, `warn`, `info`, `debug`, `trace`
`swls.ontologies`	string[]	`[]`	Extra ontology URLs to load
`swls.shapes`	string[]	`[]`	Extra SHACL shape URLs to load
`swls.disabled`	string[]	`[]`	Features to disable (e.g. `"shapes"`)
`swls.prefixDisabled`	string[]	`[]`	Prefixes from prefix.cc to hide from completions
`swls.completion.mode`	string	`"none"`	Property completion mode: `none` (server default), `loose` (all properties), `strict` (domain-matched only)
`swls.completion.strict`	string[]	`[]`	Namespace prefixes that require a matching domain even in `loose` mode
`swls.completion.except`	string[]	`[]`	Namespace prefixes always suggested regardless of domain, even in `strict` mode