Guides

In the previous tutorial we have learned how to send a reply to another ActivityPub server, and we have used mostly static parts to do it. Now it’s time to talk about how to subscribe to other people and receive messages. The inbox Primarily this means having a publicly accessible inbox and validating HTTP signatures. Once that works, everything else is just semantics. Let’s use a Sinatra web server to implement the inbox.

Today we’ll be looking at how to connect the protocols powering Mastodon in the simplest way possible to enter the federated network. We will use static files, standard command-line tools, and some simple Ruby scripting, although the functionality should be easily adaptable to other programming languages. First, what’s the end goal of this exercise? We want to send a Mastodon user a message from our own, non-Mastodon server. So what are the ingredients required?

So you want to be part of the Mastodon network, and you want to truly own your data, independent of anyone else. Perhaps you want to curate a niche community for a specific interest, or maybe for your own family or close circle of friends. You went through the documentation and installed the software, or maybe you chose one of the available hosting options to avoid all the technical nonsense altogether.

My instance mastodon.social has recently surpassed 43,000 users. I have closed registrations both to have more time to investigate the infrastructure and ensure a good experience for existing users, and to encourage more decentralization in the network (with a wonderful effect — the Mastodon fediverse now hosts over 161,000 people spread out over more than 500 independent instances!) But providing a smooth and swift service to 43,000 users takes some doing, and as some of the other instances are approaching large sizes themselves, it is a good time to share the tips & tricks I learned from doing it.