#languagetool #rust

bin+lib languagetool-rust

LanguageTool API bindings in Rust

35 releases (11 stable)

2.1.4 Aug 10, 2023
2.1.3 Jul 24, 2023
2.1.2 May 29, 2023
2.1.0 Feb 9, 2023
0.0.18 Jun 22, 2022

#77 in Text processing

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256 downloads per month

MIT license



Rust bindings to connect with LanguageTool server API.

LanguageTool is an open source grammar style checker. It can correct 30+ languages and is free to use, more on that on languagetool.org. There is a public API (with a free tier), but you can also host your own server locally. LanguageTool-Rust helps you communicate with those servers very easily via Rust code!

Crates.io docs.rs codecov

  1. About
  2. CLI Reference
  3. API Reference
  5. Related Projects
  6. Contributing


LanguageTool-Rust (LTRS) is both an executable and a Rust library that aims to provide correct and safe bindings for the LanguageTool API.

Disclaimer: the current work relies on an approximation of the LanguageTool API. We try to avoid breaking changes as much as possible, but we still highly depend on the future evolutions of LanguageTool.


You can install the latest version with cargo.

cargo install languagetool-rust --features full


If you are on Arch Linux, you call also install with your AUR helper:

paru -S languagetool-rust

CLI Reference

Screenshot from CLI

The command line interface of LTRS allows to very quickly use any LanguageTool server to check for grammar and style errors.

The reference for the CLI can be accessed via ltrs --help.

By default, LTRS uses the LanguageTool public API.


> ltrs ping # to check if the server is alive
PONG! Delay: 110 ms
> ltrs languages # to list all languages
    "name": "Arabic",
    "code": "ar",
    "longCode": "ar"
    "name": "Asturian",
    "code": "ast",
    "longCode": "ast-ES"
  # ...
> ltrs check --text "Some phrase with a smal mistake"
  "language": {
    "code": "en-US",
    "detectedLanguage": {
      "code": "en-US",
      "confidence": 0.99,
      "name": "English (US)",
      "source": "ngram"
    "name": "English (US)"
  "matches": [
      "context": {
        "length": 4,
        "offset": 19,
        "text": "Some phrase with a smal mistake"
      "contextForSureMatch": 0,
      "ignoreForIncompleteSentence": false,
      "length": 4,
      "message": "Possible spelling mistake found.",
      "offset": 19,
      "replacements": [
          "value": "small"
          "value": "seal"
        # ...
      # ...
  # ...
> ltrs --help # for more details


Since LanguageTool's installation might not be straightforward, we provide a basic Docker integration that allows to pull, start, and stop LanguageTool Docker containers in a few lines:

ltrs docker pull # only once
ltrs docker start # start the LT server
ltrs --hostname http://localhost -p 8010 check -t "Some tex"
# Other commands...
ltrs docker stop # stop the LT server

Note: Docker is a tool that facilitates running applications without worrying about dependencies, platform-related issues, and so on. Installation guidelines can be found here. On Linux platform, you might need to circumvent the sudo privilege issue by doing this.

API Reference

If you would like to integrate LTRS within a Rust application or crate, then we recommend reading the documentation.

To use LanguageTool-Rust in your Rust project, add to your Cargo.toml:

languagetool_rust = "^2.1"


use languagetool_rust::{check::CheckRequest, server::ServerClient};

async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = ServerClient::from_env_or_default();

    let req = CheckRequest::default()
        .with_text("Some phrase with a smal mistake".to_string());


Feature Flags

Default Features

  • cli: Adds command-line related methods for multiple structures. This feature is required to install the LTRS CLI, and enables the following features: annotate, color, multithreaded.
  • native-tls: Enables TLS functionality provided by native-tls.

Optional Features

  • annotate: Adds method(s) to annotate results from check request.
  • cli-complete: Adds commands to generate completion files for various shells. This feature also activates the cli feature. Enter ltrs completions --help to get help with installing completion files.
  • color: Enables color outputting in the terminal. If cli feature is also enable, the --color=<WHEN> option will be available.
  • full: Enables all features that are mutually compatible (i.e., cli-complete, docker, and unstable).
  • multithreaded: Enables multithreaded requests.
  • native-tls-vendored: Enables the vendored feature of native-tls. This or native-tls should be activated if you are planning to use HTTPS servers.
  • unstable: Adds more fields to JSON responses that are not present in the Model | Example Value but might be present in some cases. All added fields are optional, hence the Option around them.

Here are listed some projects that use LTRS.

Do you use LTRS in your project? Contact me so I can add it to the list!


Contributions are more than welcome! Please reach me via GitHub for any questions: Issues, Pull requests or Discussions.


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