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An update on Sup, the ActivityPub API

An abstract network

A little while back I shared an idea about an API service that would make it easy to build on top of the fediverse. People went wild about it on Mastodon and Bluesky, and I got lots of positive feedback.

My startup experience tells me that it’s important to validate your idea and understand your customers before you start building a product, lest you spend months or years building the wrong thing. So that’s exactly what I did.

I put out a simple survey that was really just an opener to find people who would be interested in having a conversation with me about it. I bought each person who replied a book certificate (except for one participant who refused it), and listened to why they had been interested enough to answer my questions. If they asked, I told them a little more about my idea.

The people I spoke with ran the gamut from the CEOs of well-funded tech companies to individuals building something in the context of cash-strapped non-profits. I also spoke with a handful of venture capitalists at various firms who had proactively reached out.

A shout-out to Evan Prodromou, one of the fathers of the fediverse, here: he very kindly spent a bunch of time with me keeping me honest and helping to move the project along.

What I discovered was that the people who wanted me to build my full idea were people who really cared about the fediverse, but were not going to be customers. The people who were going to be customers wanted two specific things:

A fast way to make informational bots. Twitter used to be full of informational, automated accounts. Consider accounts containing local weather updates, earthquake reports, and so on. That’s been much harder for people to build on the fediverse.

Statistics about trends and usage. Aggregate information about how the fediverse is behaving, including about how accounts are responding to individual links and domains.

While these signals were very clear, I couldn’t yet validate the core thing I’d proposed to build, which was a full API service with libraries that let people build fully-featured fediverse-compatible software. I also couldn’t yet validate the idea that existing startups would use a service like this to add fediverse compatibility to their products.

But I believe, to reference a way-overused cliché, that this is where the puck is going.

I strongly believe that the fediverse is how new social networks over the next decade will be built. I also have conviction that more people will be interested in building fully-featured fediverse services once Threads federates and Tumblr joins. It’s likely that another large network will also start supporting these protocols.

However, someone financially backing the project would be doing so on the basis of my conviction alone. I couldn’t yet find strong customers for this use case.

I think that’s okay! In the shorter term, I’m very interested in helping people build those bots in particular — it’s a great place to start and a good example of building the smallest, simplest, thing.

The original name I came up with, Sup, was taken by another fediverse project. So for now, this idea is called Feddy.

Anyway, I wanted to report back on what I’d found and how I was thinking about the project today. As always, I’d love your feedback and ideas! You can always email me at

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