Synology Photos API

Is there any documentation on the Synology Photos for interacting with it programmatically?

I noticed that all photos when you view them have a similar format to the URL and end with item_[digits]?_k=[6characters]

I haven't figured out what the ?_k= value does but the item_ is a unique ID that can be used to call up a picture and it is retained even if the source file is renamed or moved to another folder. This is handy when I'm trying to organize a lot of stuff and keep track of where they are. I started a spreadsheet with the photos I need to sort though. I would like to be able to extract this data somehow.

Any thoughts?