LibreThinker is a LibreOffice Writer extension that brings AI-assisted text editing directly into your sidebar. It integrates an LLM to help you rewrite, improve, and edit text without leaving your document.
Download the latest extension file (.oxt) from the LibreOffice extension directory. Open LibreOffice Writer, go to Tools > Extension Manager > Add, and select the downloaded .oxt file to install.
Open the sidebar in LibreOffice; you should see the lightbulb icon for the extension. Click the icon to open the extension panel, then you're ready to start using the free model!
You can also connect to a wide range of LLM APIs using your own API key.
Go to LiteLLM's model directory, and find the model that you wish to connect to. Copy its value from the Model column - eg gpt-5.2, or mistral/mistral-medium.
Set the value as the LT_LLM_MODEL environment variable in your operating system. Then set the API key as the LT_LLM_API_KEY environment variable.
Restart LibreOffice Writer. The extension will now use the LLM vendor's API, with your key, to generate the text.
See license.txt for license.
Check out the project's site librethinker.com