Gitea is federated using [ActivityPub](https://www.w3.org/TR/activitypub/) and the [ForgeFed extension](https://forgefed.org/) so you can interact with users and repositories from other instances as if they were on your own instance. By using the standardized ActivityPub protocol, users on any fediverse software such as [Mastodon](https://joinmastodon.org/) can follow Gitea users, star repositories, receive activity updates, and comment on issues.
You can use any fediverse software to follow a Gitea user. Gitea will automatically accept follow requests. The usernames of remote users are displayed as `username@instance.com`. To follow a remote user, click follow on their profile page, and a pop-up box will appear for you to type in your instance. You are redirected to your own instance, where the remote user is fetched and rendered, and you can now follow them.
When following a Gitea user, you will receive updates when they star a repo, create, fork, or make a private repo public, or follow a user. If you are using Mastodon or Pleroma, these will show up in your feed.
You can star repositories on another instance. The full name of a remote repository is `username@instance.com/reponame`. Similar to following, a pop-up box appears for you to type in your instance, and you are redirected to your own instance, where the remote repository is fetched and rendered.
You can add users from other instances to organizations. An organization has a name and an instance, so its full name would look like `orgname@instance.com`. This indicates that the organization data resides on `instance.com`. To prevent synchronization errors, this data is only synchronized one-way to other instances.
You can add users from other instances as collaborators. As mentioned previously, a repository has full name `username@instance.com/reponame`, which indicates that the repository data resides on `instance.com`. Each collaborator's instance has a copy of the repository, but to prevent synchronization errors, the copy at `instance.com` is the main copy and it is synchronized one-way to all other instances. When a collaborator tries to modify their copy of the repository, the modification is first sent to the main copy at `instance.com` and then synchronized back to their instance.
If you change your username or the name of a repository, Gitea handles this similarly to how Mastodon does. Gitea will send a `Move` activity to your followers and update your actor to point to the new actor and the new actor to point to the old actor.
