LanguageTool HTTP API Migration
LanguageTool has offered an HTTP/HTTPS API that has been stable for about ten years. Over time, the XML response
format had become inconsistent. Thus, new versions of LanguageTool will not support the old XML format anymore.
A new JSON-based output will replace the XML-based format. Some parameter names will also be changed to provide
Who is Affected by the Change?
- Anyone using our public HTTP API: you will need to change
your software to send new parameters and interpret the new JSON response format.
- Anyone running their own instance of LanguageTool to access it via HTTP/HTTPS, e.g. using languagetool-server.jar:
you will either need to stay with an old version of LanguageTool or change your software (see above).
- Anyone who has embedded LanguageTool into their web page as
documented here: you will need to re-read the documentation we provide for embedding LanguageTool on
web pages and make sure your website is up-to-date.
The --api switch of the command line version of LanguageTool will not be affected for now, but we
strongly recommend using the server mode with the new API anyway.
- LanguageTool <= 3.3 supports only the old API
- LanguageTool 3.4 and 3.5 will support both the old and the new API
- From 2016-10-01, the public HTTP API will only support the new API
- LanguageTool >= 3.6 (planned for 2016-12-28) will only support the new API
Changes in Input Parameters
Other parameters keep their name.
Changes in Result Format
The old format was an XML format. The new format is JSON and documented here.