LanguageTool

A self-hosted grammar, style, and spell checking API that supports 30+ languages. Runs as a standalone Java server with no external database required.

What You Can Do After Deployment

LanguageTool exposes a REST API at ${ZEABUR_WEB_URL}. The main endpoint for checking text is:

POST ${ZEABUR_WEB_URL}/v2/check

Quick test with curl:

curl -d "language=en-US&text=This is a example sentence with a error." \
  "${ZEABUR_WEB_URL}/v2/check"

The API returns JSON with detected errors, suggested corrections, and rule explanations.

Available API endpoints:

• POST /v2/check — Check text for grammar, spelling, and style issues
• GET /v2/languages — List all supported languages
• POST /v2/words/add — Add words to the user dictionary
• POST /v2/words/delete — Remove words from the user dictionary

Using with Browser Extensions

The official LanguageTool browser extension (available for Chrome and Firefox) can be configured to use your self-hosted instance instead of the public API. In the extension settings, set the server URL to ${ZEABUR_WEB_URL}/v2.

Configuration

• Java_Xms — Minimum Java heap size (default: 512m). Increase for better performance with heavy usage.
• Java_Xmx — Maximum Java heap size (default: 1g). Increase if you need to check very long texts or handle many concurrent requests. Recommended: at least 1g for production use.

License

LGPL-2.1 — GitHub