Hi, @smcgregor. The Large Media besides the image transformation feature of Large Media, it is simply a Git LFS service. You interact with the files in the Git LFS service (meaning the files in Large Media) using Git.
The files uploaded to Large Media using Git are not intended to be used/accessed in any other way (besides Git itself) so we do not document that API further. Now, once the files are deployed, there is the image transformation feature but otherwise they are served via HTTP like all other deployed files.
To summarize, deployed files are accessed using HTTP. Files tracked using Large Media can use the image transformation feature. Besides that, Large Media is a just like any other Git LFS backend service for storing the LFS tracked files in a Git repo.
Now, is it possible to access the Git LFS API directly and not using Git? Yes, but I cannot think of an reason to do so for a site deployed at Netlify and depending on what you are doing this use might break our Terms of Service.
Example 1 (good API use and not breaking the ToS): You are manually constructing commits somehow and pushing commits programmatically to our Git LFS API.
Is that a violation of our ToS? No. Because these are “real” commits which would be visible in the Git history to anyone cloning the repo - this would not break the ToS.
Example 2 (bad API use which breaks our ToS): You use the Git LFS API to download files for display on the website or a third-party service.
The files must be requested using HTTP request to the site and not using the Git LFS API. Using the Git LFS API for any other purpose than creating or cloning commits for this repo is a violation of the ToS.
If there are other questions, please let us know.