I think this would be a very powerful feature for Capacities. It's one of the key reasons I've hung on to Evernote so long; I can attach a file to a note, open and edit the file, and have the edits saved there on the EN platform. Capacities could do it one better by allowing the files to be synced to an already available cloud service of the user's choosing (G-Drive, OneDrive, Icloud, etc.).

Being able to reference files in OneDrive without uploading them into capacities would be super useful when working in corporate environments where information cannot be uploaded to unvetted applications.

Many file hosting services also support public / anonymous access to files / content as well. So if authentication issues are the primary hurdle that prevents this request from moving forward, I would suggest starting with the simpler anonymous access solution first, that way there would be at least some way to manage embedded content outside of Capacities itself.

I also created a similar but slightly different feature request for third party services like drawio. If this feature request was completed then it could act as an alternative / workaround solution for many other third party apps as well, since many of them support backed storage in one of the many cloud based storage solutions mentioned.

This is THE main missing feature that will draw me away from using Dropbox Paper instead. Even if I paste a Dropbox link, is does not preview correctly and does not open when clicked. It is just to cumbersome to download a file locally first, only to upload it again to Capacities. This would be a game changer.

Similar to Coda where you can embed Google docs/sheets and play with it within Capacities - Please!

Gist

Wow, this would solve all the "where should I store it" problems for me. Sounds wonderful as described.

As an alternative drive, I would like to propose Filen.io

I know most people use GDrive or OneDrive, but also a lot of us are here exactly trying to detach from those big platforms. Filen recently published their SDK integration documentation and I think this opens up the possibility.

That should also include the iCould and other self hosted storage and syncing services.