> Can the authors (holding the copyright) distribute code under a different license when there were external contributors under GPL? No, if any contributions w

> Can the authors (holding the copyright) distribute code under a different license when there were external contributors under GPL? No, if any contributions were made under the GPL, they'd have to get permission to change the license to AGPL from every contributor or remove their contributions. Most projects like this require you license your contributions in a way that lets them sell non-AGPL licenses (see their Contributor License Agreement) https://cla-assistant.io/paradedb/paradedb https://cla-assistant.io/paradedb/paradedb So basically they can do whatever they want with your contributions.