Show HN: I built an interactive HN Simulator (news.ysimulator.run)

538 points by johnsillings ↗ HN
Hey HN! Just for fun, I built an interactive Hacker News Simulator.

You can submit text posts and links, just like the real HN. But on HN Simulator, all of the comments are generated by LLMs + generate instantly.

The best way to use it (IMHO) is to submit a text post or a curl-able URL here: https://news.ysimulator.run/submit. You don't need an account to post.

When you do that, various prompts will be built from a library of commenter archetypes, moods, and shapes. The AI commenters will actually respond to your text post and/or submitted link.

I really wanted it to feel real, and I think the project mostly delivers on that. When I was developing it, I kept getting confused between which tab was the "real" HN and which was the simulator, and accidentally submitted some junk to HN. (Sorry dang and team – I did clean up after myself).

The app itself is built with Node + Express + Postgres, and all of the inference runs on Replicate.

Speaking of Replicate, they generously loaded me up with some free credits for the inference – so shoutout to the team there.

The most technically interesting part of the app is how the comments work. You can read more about it here, as well as explore all of the available archetypes, moods, and shapes that get combined into prompts: https://news.ysimulator.run/comments.html

I hope you all have as much fun playing with it as I did making it!

147 comments

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lol, finnally, comments are coming to one of my posts
This will almost certainly be used by people to sanity check their HN submissions before actually submitting, very similar to having AI review your branch before submitting a PR.

Here is what it has to say about itself: https://news.ysimulator.run/item/113

Checking the comments of a couple of posts, I noticed their lengths seem to be too uniform. E.g. one post had all comments that were about a similarly-sized paragraph long. Another had a little more variety, but almost all comments were at least a full paragraph, with more multi-paragraph comments than I'd expect in total. Having more single-sentence comments with some one-liners sprinkled in (not always with punctuation/capitalization/etc) would make it more "realistic."
Great fun!

You should add the 80 character limit on the title as well!

I'm reminded of Vernor Vinge's "Friends of Privacy" - a group he imagined might post 1000s of times more content via AI than humans do in an effort to obscure real human data. Keep it up!
I love being able to read the prompt for every comment, it's like going to the zoo
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The prompts are hilarious and an accurate representation of the average Hacker News commenter
Now I need to build a tool that gets my comment history and categorizes me according to your archetype, mood and shape.
It tracks

> Seriously? You needed GPT-7 for that? Real genius move, typing "cure cancer" into a box. I could've solved it with `curl` and a three-line Python script. Just query PubMed's API and randomize the results—same scientific rigor, probably faster. Next time, try less hype and more basic scripting.

This is fun! I just posted about my startup and I loved the responses. They were criticizing a lot though, it was fun haha!
This is so cool. I feel like I've been made obsolete as an HN commenter though, pretty soon we will just have bots discussing stuff for us on HN and then giving us an efficient summary of what we would have read and written on HN that day.
It's already here, just download OpenAI's AI browser and tell it to do it for you and then go back in the yard and just lay down to die because if even that tiny bit of joy I get from posting here is better done by a fucking robot, what point is there to life anymore.
super cool. just tried it. love the sassy comments
That's actually quite cool. I submitted my start-up and go very similar responses to what I expected, though maybe a bit less challenging than what we usually get, less complaining about subscription, etc etc.
One of the top posts in mine is “Interactive HN Simulator”. I appreciate the meta. It immediately got a chuckle out of me.
I love this and its pretty fast. Hilarious comments. The economist one is pretty lenghty though, you might want to adjust the prompt.
Needs a dang archetype, who merges similar posts.
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