Hacker News has no posting API, an audience that flags promotion within minutes, and moderators who read. That combination makes it the one network where automation is both impossible and unwise. It is also, for technical products, the highest-quality traffic there is. Treat it as a place you take part in yourself, with help finding the threads.
Reading is the automatable part
Ask HN and Show HN threads, and new comments, are readable through the public API. Watching them for questions you can genuinely answer is worth automating, because the good threads are spread thin across a lot of noise. Posting is not: write it yourself, from your own account, with your own name.
What a good reply looks like
Dry, specific, technical, with the affiliation in the first sentence when it is relevant. Longer than a Reddit reply, because the audience reads. Cite the trade-off. No marketing language at all; "we help teams unlock" gets downvoted on sight.
If your product is relevant: "I work on X, so biased, but the thing you are describing is usually caused by Y, and here is how to check." Then the actual content.
Show HN
The rules are short: it has to be something people can try, the title says what it is without adjectives, and the first comment from you explains why you built it and what is unfinished. Honesty about limitations is what earns the upvotes.
Timing matters less than people think; substance matters more. Do not ask friends to upvote. Voting rings are detected and the post is killed.
Replying to comments
Answer every substantive comment in the first hours, including the critical ones, especially the critical ones. The thread is the product demo.
What to avoid
Posting a link with no comment. Replying to threads where the product is a stretch. Any mention of "excited to announce." Pasting the same reply you used elsewhere; the overlap in readership is large.
How Gorilla Desk handles it
The Hacker News agent reads Ask HN, Show HN and new comments for questions you can answer in full, drafts a longer reply, and hands it to you with a one-tap button that opens the thread. It never posts for you, because nothing should.