Didn’t HN get an official API a long time ago? Or was that read-only?
Link at the bottom of HackerNews that says “API” points to this GitHub repository [1].
The first commit is from Oct 2, 2014 while the article was published on April 1, 2018.
However, it seems that you did not read the first paragraph of the article which states the following:
> While building hackd I faced a problem - the official Hacker News API doesn’t allow for interaction, such as upvoting, posting and commenting. I wanted hackd to be a full featured Hacker News client, so this wasn’t going to cut it.
So to answer your question:
> Didn’t HN get an official API a long time ago? Or was that read-only?
Yes, it appears that at the time of publication, the API was read-only.