This is awesome, and it's just the kind of thing I was looking for and I might use it! I wish I'd known about Express ActivityPub Server as I have questions/thoughts on it.
There are a lot of moving pieces to this- the AP server, beanstalk, the OAuth server- maybe a longer tutorial would be good about helping all the pieces fit?
Also can I contact you about what I'm doing and maybe areas of possible intersection?
@emacsen you're right, I could write up something longer
And feel free to tell me what you're up to!