So, I thought about this one a bit more today and I lean towards a dynamic implementation using a view, not generating a static number of images.

The reason for this is that for project avatars, we want to always show the GitHub avatar_url first if it exists. This means that this image will always have conditional logic, and I can't always reference that logic from front end code.

However, if this is instead a dynamic view, we can make the decision to redirect the image to the remote repo avatar URL, and if that image isn't defined, show our own generated avatar instead. In this case, I do not need to make a decision inside templates or front end JS whether to show the GitHub avatar or our avatar, I can instead just point to a URL:

<img src="/projects/test-builds/images/avatar/" />

This was already on my radar, as the Dicebear images were a bit of a placeholder, but I got excited about writing some Python for once and landed on something usable:

The images are reproducible SVGs, based on a random seed for the project. I used the Dicebear "initials" avatar SVG source to generate our template. We'd want to cache for some amount of time of course.

The idea would be a project avatar, but also eventually user, team, and organization default avatars.

There is some stuff to talk through in my implementation, so I'll put it up as a draft and we can talk more there.

With an API v3 change, it would be possible to do this all from the front end side instead

This is now possible (see readthedocs/readthedocs.org#10513)

Generating an SVG here is still an option, but I just realized that generating a single sprite image is also an option and one that would be avoid multiple requests and able to be cached too.

The current Dicebear variant is stacked shapes, but other options like zoomed in pixel art could be used here too. The sprite image could be used with or without overlap, giving a fair number of unique combinations for a small image.

Pixel art especially, as we can zoom in instead of using an image with the final aspect ratio. For example, the project avatar images could be 4x4 pixels zoomed to 40x40px. With 50% overlap, a 160x100px sprite image can have ~3800 combinations and would <20Kb uncompressed.

.avatar {
  background-image: url("foo.gif");
  background-size: 1600px 1000px;
  width: 40px;
  height: 40px;
  image-rendering: pixelated;
}

.avatar.1a {
  background-position-x: -800px;
}

.avatar.2b {
  background-position-y: -500px;
}

/* <div class="avatar 1a 2b">Project with initials AB</div> */