I’ll be leading a session on the Browser experience of ActivityPub social networking as part of W3C Breakouts Day 2025. This is a virtual event, open to all members of the Web community; connection information in the link.

ActivityPub encourages interconnection between independent, heterogeneous social networking platforms. One of the most confusing parts of the ActivityPub network for many users is interacting with people and content on remote servers. How can you like, share or reply to an image or article on one server with your account from another server? How can you follow or block a person whose profile page you are looking at?

I briefly outlined one solution to this problem on Cross-server Interactions in ActivityPub on my personal blog last year. In that article, I cover how remote servers can act as clients for your home server, sending your activities directly to your ActivityPub API endpoint.

In the breakout session, I’ll be going over another solution: letting the browser be an API client on its own. The Social Web Incubator Community Group (SocialCG) has a task force for ActivityPub HTML discovery, with a draft report on ActivityPub discovery . This report shows how we can surface API information about a person or content in the HTML pages displayed in the Web browser. In the session, I’ll discuss how that API information could be used in a browser extension to make API calls for liking, sharing, replying to the content on the page, or following a person.

I’m especially interested in developing a proof-of-concept browser extension for Vivaldi (my daily-drive browser) to show how this can work.

If you’re interested in deeper integration of social networking features into the Web browser, please make sure to come to the talk!