GroupShare comes with a Rest API that allows you to do browse information available in the system. You can build a desktop, web or mobile application that can use the resources that are available in GroupShare. Now in order to connect those user must be created in GroupShare or you can create them using the API. For more information try this url on your GroupShare instance http://{Replace with you groupshare url or ip}/documentation/api

Thank you for your answer.

We had a look at the API and also thought about copying each user to GroupShare using the API. The problem is that we don’t know the users passwords because they are not saved plain text but hashed.

We tried to find out if there is a possibility to hook our user database with GroupShare so that we wouldn’t have to copy any users at all. Is that somehow possible? For example using OAuth2 (we saw that GroupShare is using OAuth2 libraries)?

And we also wondered if the User Type "Custom" could help us somehow. But we haven't found any documentation about user types.

You are correct the custom user type is there in the case you provide your custom authentication mechanism. To do that you need to create a custom authentication provider in GroupShare. More details on how to do that can be found here:

You are correct the custom user type is there in the case you provide your custom authentication mechanism. To do that you need to create a custom authentication provider in GroupShare. More details on how to do that can be found here: