A few Wikisources are moving metadata to Wikidata and then reading it back again with custom Lua modules. English, French, and Spanish have done this for authors (see Q26966406) to some degrees.
This task is to continue this process where appropriate, and so reduce the duplication of data in Wikisource.
Modules need to created for authors and works and integrated into the existing templates for these. There are still lots of questions that remain to be answered about how best to set up certain metadata on Wikidata, but there are lots of things that we do seem to be pretty settled on. For example, a work on Wikisource is a specific edition, and so has a publication date of its own (i.e. not necessarily the date of original publication) and this needs to be displayed in Wikisource. At the moment, it's usually recorded there and at Wikidata.
If this hack session achieves nothing else, even getting a single attribute to be read from Wikidata (when it's left blank in the local template) would be a good job. In doing so, we learn more about what data structures we need, and we reduce the chances of error throughout the system.
[Feel free to edit this description if it's lacking anything.]