Federation for multiple blogs in subdomains

I just signed up for hosted Write.as and I are playing with a multi-blog design, where I aim to separate my different writing genres using a “sub.domain.tld” each under the same “domain.tld”.
Now, I find it strange to see a federation option to resolve like


and so on. I understand that this is partially related to fediverse design, but could there be a better solution here, for Pro custom domains users, because I suspect there will be more people using the same domain. For instance when I use a “subdomain.write.as” as a blog domain instead I’ll get “at-custom_name@write.as”.

What I wish would be to map my “sub-domain-blogs” as “at-blog1@domain.tld” “at-blog2@domain.tld” and so forth or at very least to have an option to choose “at-custom_name@write.as” for each of my blog (as I get with a “write.as/custom_name” or “custom_name.write.as” options.

What do you think, @matt ?

P.S. sorry I had to us “at-…” in federation addresses, the discuss doesn’t allow me to publish topic with multiple “at symbols”, considering them mentions

Hey @levlc, this is an interesting point – something that hasn’t come up before.

The trick is that ActivityPub goes by host name and doesn’t differentiate by subdomains. You could put all handles on a top-level domain and have usernames for each subdomain (maybe), but this would require a ton of configuration and include plenty of complexity to make sure everything still works in the fediverse. The design we went with simply gives everyone the most straightforward way to get a blog in the fediverse on whatever domain they’re using – whether one or many.

If you’d like everything to appear on a single domain, honestly the best route would probably be to host a multi-user WriteFreely instance on it. If you put that on domain.tld, you could get @blog1@domain.tld and @blog2@domain.tld automatically.