LanguageTool — ZedExt

LanguageTool Zed Extension

LanguageTool integration for Zed. The Zed extension launches a Rust language server, which sends document text to a local or cloud LanguageTool HTTP API and publishes diagnostics and quick fixes through LSP.

Local Development

Run extension checks:

cargo make check

Run a LanguageTool server on localhost:8081, then build the language server from the sibling languagetool-lsp repository and add it to the PATH.

cargo build --manifest-path ../languagetool-lsp/Cargo.toml -p languagetool-lsp

Install this repository as a Zed dev extension. The extension prefers a languagetool-lsp on PATH, then a downloaded release binary.

Example Zed settings:

{
  "lsp": {
    "languagetool": {
      "initialization_options": {
        "backend": { "type": "local", "url": "http://localhost:8081" },
        "language": "en-US",
        "checkOnSave": true,
        "checkWhileTyping": false
      }
    }
  }
}

LanguageTool Backends

Local backend, default:

{
  "backend": { "type": "local", "url": "http://localhost:8081" }
}

Cloud backend:

{
  "backend": { "type": "cloud" },
  "language": "auto",
  "preferredVariants": ["en-US"]
}

Commands

cargo run --manifest-path ../languagetool-lsp/Cargo.toml -p languagetool-lsp -- --root . health
cargo run --manifest-path ../languagetool-lsp/Cargo.toml -p languagetool-lsp -- --root . check test-fixtures/plaintext/basic.txt

Project Config

Workspace quick fixes can create or update .zed/languagetool.json by default.

{
  "ignored_words": ["zed"],
  "disabled_rules": ["WHITESPACE_RULE"],
  "disabled_categories": ["TYPOGRAPHY"]
}

The LSP merges this file with Zed initialization_options. Values from both sources are kept for ignored words and disabled rules/categories.

The path can be changed with projectConfigPath for non-Zed workflows:

{
  "projectConfigPath": ".idea/languagetool.json"
}

Available command-backed quick fixes:

Ignore a single matched word in the workspace.
Disable a LanguageTool rule in the workspace.
Disable a LanguageTool category in the workspace.

After one of these commands updates .zed/languagetool.json, the server rechecks open documents.

Current Scope

Plain text, Markdown, MDX, HTML, and a conservative set of common code languages are registered in Zed.
Markdown and HTML are sent with LanguageTool data.annotation, marking code fences, inline code, links, tags, scripts, and styles as markup.
Code languages currently send comments as text annotations and code as markup, with Python triple-quoted strings treated as documentation.
Quick fixes are generated from LanguageTool replacements.
Ignore/disable actions persist to the configured project config path.
On-change checking is debounced when checkWhileTyping is enabled.