The backend server, Atuin Hub (https://hub.atuin.sh), isn't currently open source, but the open source desktop app can still connect to it. We also support offline workspaces if you prefer using Git or another VCS to manage and collaborate on runbooks, rather than using Atuin Hub.
Following the Obsidian model, which I love and support. Give folks the best part of the product, offer a paid option to enhance it, but allow folks to use alternatives as first class options.
Thank you for the candid response. So team collab without the hub is still possible, but the desktop client becomes a viewer for a hit repo. Am I understanding that correctly? The advantage of the hub is that that is all handled under the hood?
A viewer and editor, but essentially yes — the Hub handles sharing and collaboration for you, as well as realtime collaborative editing and a few other features (and likely a few more to come). We want the Hub to feel like the most frictionless way to collaborate on runbooks, but we understand that some folks don't want host their runbooks with a third party, and sometimes fitting into an existing VCS workflow makes the most sense.