Do you mean to subscribe to the whole collection, one RSS feed for all the blogs in my list? I mean, I guess I can build that feature, but it's gonna be quite a firehose.
Not sure what parent meant, but the right way should be an opml file with the feeds, which the feed reader then can import. But maybe you are offering that already?
One tip: Every Substack has a feed, which is a nice alternative to having everything dropped in your email in-box. You just append "/feed" to the end of a newsletter URL, e.g. https://simonw.substack.com/feed.
I've been doing adjacent work for my search engine[1], and found substack to annoyingly be one of the sites that employ bot mitigation for its RSS endpoints. If you fetch at a very low rate it works fine, but for these types of bulk retrieval.
Substack is also a bit of a pain to integrate with because they have zero useful contact information and direct all inquiries to a chatbot that is beyond useless, makes it so you have to guess how they want you to interact with their servers since there is nobody to answer questions.
I think the answer to this question _should_ be blogrolls, as in, you discover new feeds from the feeds you already like. We lost that when social media absorbed the social graph, but blogs and feeds are in vogue again.
I built a site around programmatic blogrolls (sites that publish an OPML file of their recommendations using a specific format). I collected a bunch of initial subscription lists[1], which are curated lists, "planets", and web rings. The I spider out from there. The aggregate list is too diverse, and definitely has some low quality content, but connections between blogs are useful for discovery [2].
I am working on a site, which is very pre-beta at this point, that works to help solve this problem using bluesky's "starter pack" model. Basically sharing curated lists of good follows. Give it a look at https://feed.computer if that seems interesting!
I think OP’s project is a nice place to potentially have some default feeds. Both for purposes but also because it’s nice to see some interesting content once you sign up. Maybe even just major news items.