An example of a more pragmatic approach to image uploads, for example, is the mastodon API. You still have to use a separate multipart request for an image, but the description (alt) text accompanies the image as an additional field. I think you can probably use the same image (and by extension its alt text) for multiple posts if you want. This fits because alt text is descriptive, so it shouldn't depend on the context the image is used in. #indieweb