I searched for a mastodon embedding tool and found a javascript app written by someone that does exactly what I want it to do. The source code is beautifully simple and so I'm going to rip out the queries and use it to write a mastodon embedding utility for myself.
The programmers dilemma! I want the utility to somehow already exist but as soon as I find the utility I have the urge to do it myself. What is this affliction.
https://gitlab.com/idotj/mastodon-embed-feed-timeline/-/blob/master/src/mastodon-timeline.js
This is the code I'm going to take inspiration from.
The following query will get you the user id from mastodon.social given a username:
curl https://mastodon.social/api/v1/accounts/lookup?acct={ACCT}
The following query will get the last 20 posts from the above user id:
curl https://mastodon.social/api/v1/accounts/{USERID}/statuses?limit=20