Synology DSM

DAVdroid has been successfully tested with Synology DSM.

Synology DiskStation Manager (DSM) is a Linux based software package that is the operating system for Synology's DiskStation and RackStation products. A CalDAV server is available in the base system. CardDAV can be installed as an extra package. It's also possible to run other CalDAV/CardDAV software like Baïkal and ownCloud on Synology systems. In this case, see the respective configuration pages for details.

DAVdroid settings for Calendar

The Calendar package provides a calendar with Web and CalDAV interface.

You can view the CalDAV URL in the Calendar Web interface (Calendar > CalDAV Account). Use the macOS / iOS URL, but you may have to replace /caldav/ by /caldav.php/ (bug report).

So, the CalDAV Base URL could look like this:
http://diskstation.lan:5000/caldav.php/username

DAVdroid settings for CardDAV Server

The CardDAV Server package provides a CardDAV server with address book backend in the Web interface.

CardDAV Base URL:http(s)://example.com:port/addressbooks/users/<yourUserID>/addressbook

User name and password: same as for Synology DSM

Contact group method: groups are separate VCards

Known problems

If you're accessing a newly created calendar/task list, Synology returns 404 Not Found when this collection is queried by DAVdroid. To work around this, add an event and a task to the calendar (e.g. with DAVdroid). Then synchronize and the 404 error should be gone.