texlsp LaTeX Language Server for VS Code

VS Code integration for texlsp, with a bundled WASI runtime and an optional native executable fallback.

Author: Yifan Yang yfyang.86@hotmail.com

No Rust installation is needed for the default runtime. The extension includes server/texlsp.wasm and uses Microsoft's ms-vscode.wasm-wasi-core extension, which is installed automatically as a dependency. Native binaries are optional. This release targets desktop VS Code, not browser workers.

Features

• Diagnostics for unmatched environments, duplicate labels, and undefined references/citations.
• Context-aware command, environment, label, citation, file, and package completion.
• Go to definition, hierarchical document symbols, and macro hover.
• Safe-subset document formatting.
• texlsp.expandMacro integration that applies the server's edits to the original document and rejects stale responses.
• Start, stop, restart, output, and LSP trace controls.

File and untitled documents with the latex, tex, or plaintex language ID are supported. VS Code supplies the built-in TeX/LaTeX grammars; this extension does not replace them.

Server runtimes

Bundled WASI (default)

No setup is required beyond enabling the ms-vscode.wasm-wasi-core dependency. The extension starts the bundled server/texlsp.wasm with shared memory and mounts the current workspace for bibliography and include-file access.

Native executable (optional)

Install the published source with Cargo (requires a Rust toolchain):

cargo install --git https://github.com/yfyang86/rsTexLSP

Alternatively, from a repository checkout, run cargo install --path .. Select native mode and, if necessary, configure the executable:

{
  "texlsp.runtime": "native",
  "texlsp.serverPath": "/absolute/path/to/texlsp"
}

A bare texlsp value uses PATH. When using a remote workspace, install the native server in that remote environment.

Install the extension

Marketplace

code --install-extension yfyang.texlsp-vscode

Local VSIX

From editors/vscode:

npm ci
npm run package
code --install-extension texlsp-vscode-0.1.0.vsix

Reload VS Code if prompted, then open a .tex file. The server starts automatically by default. Installing a local VSIX does not publish it to the Marketplace.

Settings

{
  "texlsp.runtime": "wasm",
  "texlsp.serverPath": "texlsp",
  "texlsp.serverArgs": [],
  "texlsp.autoStart": true,
  "texlsp.trace.server": "off"
}

• texlsp.runtime: wasm uses the bundled WASI module; native starts the configured executable.
• texlsp.serverPath: native mode only. An executable name, absolute path, or workspace-relative path. A bare name uses PATH; a relative path containing / or \ is resolved from the current workspace folder.
• texlsp.serverArgs: native mode only. Additional executable arguments.
• texlsp.autoStart: start when a supported document is activated. If disabled, use the start command manually.
• texlsp.trace.server: off, messages, or verbose. Trace output appears in texlsp Trace; client messages appear in texlsp.

Changing the runtime, executable, or arguments restarts a running server. Changing trace verbosity does not require a restart.

Commands

Open the Command Palette and search for texlsp:

• Start Language Server (texlsp.start)
• Stop Language Server (texlsp.stop)
• Restart Language Server (texlsp.restart)
• Expand Macro Under Cursor (texlsp.expandMacroAtCursor)
• Show Output (texlsp.showOutput)

For macro expansion, place the cursor on a command defined with \newcommand and run Expand Macro Under Cursor. For example, with \newcommand{\swap}[2]{#2/#1}, expanding \swap{A}{B} produces exactly B/A.

Normal VS Code gestures work without extension-specific keybindings: hover, completion, go to definition, document symbols, and format document.

Development and verification

Use Node.js 22 or newer and install the WASI Rust target once:

rustup target add wasm32-wasip1-threads
npm install
npm run check
npm test

npm test builds native and WASI release artifacts, then runs the complete integration suite in a real VS Code Extension Development Host once for each runtime. Fresh profiles and extension directories isolate the tests from your normal setup; ms-vscode.wasm-wasi-core is installed only in those profiles. The standard macOS VS Code installation is used when present, otherwise test-electron downloads VS Code. VSCODE_EXECUTABLE_PATH can select another actual VS Code executable (not the code CLI wrapper). For example:

VSCODE_EXECUTABLE_PATH="/Applications/Visual Studio Code.app/Contents/MacOS/Code" npm test

The tests exercise diagnostics, definition, completion, symbols, hover, formatting, macro expansion, bibliography access, incremental updates, restart, and shutdown. Artifacts are written under target/tmp.

Build the WASM artifact or package the complete extension with:

npm run build:wasm
npm run package

npm run package rebuilds the WASM artifact through vscode:prepublish.

License

The extension and server are available under either the MIT License or Apache License 2.0, at your option. See LICENSE-MIT and LICENSE-APACHE.