I’ve previously written about the ActivityPub communication that happens when someone wants to follow a community on a remote instance, because that’s what I was coding at the time. A week later, things have moved on a lot and one…

ActivityPub involves servers doing a lot of HTTP POST-ing of JSON at each other and there’s always a claim in the JSON about who did the Activity being described. However AP does not include a mechanism for ensuring that the…

One of the gaps in ActivityPub is that even though there is a specified way to provide all the information about a user (an “Actor”, in AP), there is no way to know what URL to query to get that…

One of the special design decisions made during the development of the ActivityPub protocol was that the format of the data being sent between servers would not just be JSON, but something a bit different called JSON-LD. From what I…

Welcome to the inaugural post in a series about things I’ve discovered about how ActivityPub works in the real world, beyond what the spec says. While the spec is pretty good and easy enough to understand there is a lot…