LanguageTool is an Open Source proofreading software for English, French, German, Polish, Russian, and more than 20 other languages. It finds many errors that a simple spell checker cannot find.
View https://languagetool.org for more information.
Requires one prt for comunication.
Try addr:port/v2/check?language=en-US&text=this+is+a+test
to test