Show HN for October 31, 2025

I went down the rabbit hole on a side project and ended up building this: Strange Attractors(https://blog.shashanktomar.com/posts/strange-attractors). It’s built with three.js.

Working on it reminded me of the little "maths for fun" exercises I used to do while learning programming in early days. Just trying things out, getting fascinated and geeky, and being surprised by the results. I spent way too much time on this, but it was extreme fun.

My favorite part: someone pointed me to the Simone Attractor on Threads. It is a 2D attractor and I asked GPT to extrapolate it to 3D, not sure if it’s mathematically correct, but it’s the coolest by far. I have left all the params configurable, so give it a try. I called it Simone (Maybe).

If you like math-art experiments, check it out. Would love feedback, especially from folks who know more about the math side.

This project is inspired by 37signals’ ONCE idea. I replicated the whole process and have already sold a few copies (the testimonials are real).

Hi HN — Bracket City is the word puzzle game I made earlier this year and (in part thanks to this community, see https://news.ycombinator.com/item?id=43622719) managed to license to the Atlantic in April.

The game has been growing a lot and I wanted to share the latest: a tool that lets anyone make a Bracket City puzzle — specifically a “Bracket Suburb”!

I made this tool to help me construct puzzles, and I’ve been using it every day for months.

After the Atlantic launch, I started to get the occasional inquiry about whether there was a way to make your own puzzle. One guy wanted to make a Bracket City puzzle part of a puzzle hunt he made to propose to his girlfriend (he did it!), and that convinced me it would be fun to make something publicly available.

I got the Atlantic on board with the idea, and we are launching it today with an "example" custom puzzle: a Halloween/horror-themed puzzle by my pal Wyna Liu of NYT Connections fame.

https://suburbs.bracket.city/wyna

And we've got few other fun "celeb" puzzles lined up for later this year.

The thought is that folks can use the builder to make custom puzzles for birthday wishes/event invites/insults/proposals/break ups in addition to “normal” Bracket City puzzles.

I'm also hoping to learn more about the potential of the format – crossword puzzles have benefited so much from the creativity of constructors – I'm hoping bracket puzzles do the same.

The good news is that it’s way easier to construct a bracket puzzle than a crossword. Once you try it, you’ll see why: you have many more degrees of freedom. In a crossword, each added word increases the level of constraint exponentially — every new entry sharply reduces the remaining options for completing the grid. Bracket puzzles are the opposite: as you add clues, you expand the available fodder for new ones.

Anyway, I would love any/all feedback and to try puzzles created by folks here. I’m hoping we will figure out a way to highlight the best community puzzles on the Atlantic soon!

PS and please keep playing the main game / sending me feedback / denouncing me on the subreddit

I build a skype clone, where you can make international calls via browser.

Skype was my go to app for that, but since they shut it down, decided to build my own. Its perfect for calling international customer support, or any other gov numbers.

Its pay-as-you-go - so no subscription charges, very transparent pricing. You can just top up $5 and see pricing in real time during the call.

Hi, I started building Loopletter, an open-source email marketing platform built specifically for independent artists and creators. I've been using this for a while to run marketing campaigns for my own company. But due to the lack of time to update it i've decided to open it up under the MIT license so other people and industries can self-host, extend, or just learn from the codebase.

  What’s inside:
  - Full campaign builder (visual editor, reusable templates, optional Spotify-powered layouts)
  - Audience management tooling (imports, segmentation, consent workflows, list cleanup)
  - Queue-driven sending with AWS SES, BullMQ, and Redis — handles rate limits, retries, and
  deliverability feedback
  - Analytics dashboards with real-time metrics, campaign history, and basic attribution
  - Infrastructure scripts for Supabase, AWS EventBridge/Lambda, and Upstash Redis so you can set
  everything up from scratch

  Tech stack: Next.js, React 19, TypeScript, Tailwind, Clerk for auth, Supabase (Postgres)
  for storage, AWS SES + S3 for mail/asset delivery. The repo has docs, scripts, and a demo data
  sandbox because we know email platforms can be boring to set up without real content.

  Why open-source? Most tools in this space are either huge enterprise SaaS products or
  very marketing/sales oriented. Independent artists have different needs (merch drops, tour
  announcements, limited release windows) and usually lean on social platforms they don’t control.
  Email still converts best for them, but standing up a full stack is painful. We’d love to see
  small labels, agencies, and indie devs fork it, run it for their communities, or contribute
  features.

  I'm especially curious if this has potential to be something bigger.

  Repo link: https://github.com/createdbymax/Loopletter-Open-source-email-marketing-platform
  Production website: https://loopletter.co/

  Happy to answer questions about the project, SES deliverability, or anything else related to
  running email at indie scale. Thanks for taking a look!

I built a 24h Halloween radio stream hosted by Dr. Eleven, using ElevenLabs and HLS for delivery. Excited for you to hear it + open to any feedback.

When my wife and I bought our first home in 2020, it was peak COVID. Our agent actually asked us to waive the home inspection, which was terrifying. I ended up walking through the house myself with a set of handwritten notes: “check if Kitchen outlets are GFI,” “make sure toilet flushes”, “test the bath fan”, etc.

That experience became the seed for Dwellable, a home maintenance and inspection app for homeowners like us who didn’t know where to start (both before and after buying).

The app automatically pulls your property records (square footage, year built, fuel type, etc.) and uses AI to recommend reminders and seasonal maintenance tasks. It’s free right now, built entirely native on iOS and Android.

On the side, I’ve been experimenting with VLMs (vision language models) to analyze photos that users take during inspections, for things like spotting corrosion or damaged caulking.

If you’ve ever felt lost after closing on a house, this might resonate.

Would love feedback!

I built Cuiz-AI to generate practice quizzes from PDFs, Word docs, and PowerPoints using AI.

The name is a play on "Quiz" + "Cuis", a small rodent from Argentina, where I'm from. That's why the logo is a little rodent.

The tricky part: Getting an LLM to generate quality quizzes fast was quite hard. I spent a lot of time testing different models and approaches to get the generation time down from minutes to seconds.

You upload a document, the LLM reads it and generates multiple choice questions with explanations. It also tracks your quiz history and progress.

Would love feedback, especially on use cases I might not have thought of and in the quality of the questions!

https://www.cuiz-ai.com/

thank you!

Over the past months, I’ve been working on somethings scary - bringing modern frontend tooling (Vite, HMR, modular builds) into traditional PHP projects.

This resulted in (currently) three small open-source projects:

- A NPM package for Vite: https://www.npmjs.com/package/vite-plugin-php

- A Packagist package: https://packagist.org/packages/nititech/html-components

- And an additonal NPM package to transpaile those components: https://www.npmjs.com/package/vite-plugin-php-components

The goal is to make PHP feel modern again: fast rebuilds, componentized UI, and zero JS lock-in.

It’s early but already usable — feedback, ideas, and contributions welcome.

Here is a starter repo to play around with: https://github.com/nititech/modern-php-vite-starter

Hi everyone I have been experimenting with a simple idea. What if the first five minutes of your day decided the rest? I built First5Minutes, a small web app that helps you start strong. You choose one meaningful mission for the day and complete it with quick photo, video or text proof. I created it to fix my own habit of overplanning and not starting. The focus is on doing one real thing each day, not maintaining long to do lists. Key features: • One mission per day for focus • Quick proof capture with photo, video or text • Optional partner verification for accountability • Streaks based on proof, not checkmarks Try it here → https://first5minutes.app No install or sign up wall. Just start a mission. I would love your feedback on: • Is this level of simplicity helpful or limiting • What part made or failed to make you feel you actually did something • Any friction in completing your first mission Built with Next.js, Supabase and Clerk. Thanks for checking it out. I appreciate your time and thoughts.

I made this little logger because logging JSON without escaped strings seemed really unintuitive.

I hope you find it useful!

Hey guys. Mach is a pet project of mine that I've been designing and implementing for the better part of two years now. It's a C-like systems programming languages that takes inspiration from and attempts to combine the best parts of languages like C, Rust, Zig, and Golang in particular.

Modern systems programming languages focus so much on "features" like fancy memory management, large amounts of syntax sugar for less typing, unique type systems, fancy interop, and more that just gets in the way. Mach is an attempt to bring all that back down to earth.

In practice, Mach should feel like writing C with a few extra nice-to-haves.

The project is in a very alpha stage, but does have a fully operational bootstrap compiler implementation as well as a full (scrappy at best) language documentation. I'm looking right now to involve people that would like to contribute or nitpick the project. It's not perfect -- far from it, but the philosophy is sound.

Take a look and let me know what you think, or, better yet, join the discord and tell me what you hate about it there. Mach is at the phase right now where what it needs is heavy scrutiny and criticism to lock it down into a distinct forward path. If you can provide that, please do!

If you’re into Roblox tower defense or anime-themed games, Anime Last Stand (ALS) is a must-play—and Anime Last Stand Wiki is your shortcut to mastering it. Built by real players (500+ hours tested, no AI fluff), it cuts to what fans need: Daily Verified Codes: Grab active rewards like NewHeights (1000 Rerolls + Title) or SlimeGodly! (100 Rerolls + Pearls) – no expired duds. Tested Guides: Beginner tips, meta team comps, and deep dives into Update 73 (Godly Rimuru, Halloween Part 2). Reliable Stats: 40+ unit tier list, 30+ character database (even Godly Rimuru’s 0.03% drop rate), and exact status effect damage. No fluff—just what you need to crush waves, climb leaderboards, and get rare units. Check it out:https://animelaststand.net/

We built Sentient to automatically extract themes and sentiment from customer feedback without manual configuration. The system processes documents in sub-second time while maintaining 95% accuracy.

Built with Next.js 14 and FastAPI, using fine-tuned OpenAI models trained on millions of feedback examples. Key features include automatic customer segmentation, multi-format support (PDF, DOCX, CSV), and real-time processing.

The core insight: most tools analyze individual reviews instead of understanding customer journeys and behavioral patterns. Sentient connects feedback sentiment to business outcomes through multi-phase AI analysis.

Technical approach uses theme detection, emotion recognition, and intelligent caching for enterprise-grade performance.

Try it at: https://data-decoder.vercel.app/

Hi HN!

I believe people here are somewhat familiar with Iroh - the p2p networking library. It does Hole-punching and make use of QUIC connections between endpoints to enable peer-to-peer connectivity

https://www.iroh.computer

https://news.ycombinator.com/item?id=44379173

https://news.ycombinator.com/item?id=4572755

Easiest way to make use of Iroh is through their in-house file transfer CLI tool called sendme

https://www.iroh.computer/sendme

Sendme uses iroh to establish direct links between devices for data transfer, and iroh-blobs to send and verify your files

Features:

- Free, for files & folders of any size

- No account requirement

- No server component

- Fast - can saturate a 4Gbps connection.

- Resumable fetching - Interrupted downloads pick up where they left off.

- Integrity checks - Data is automatically verified for correctness on both send and receive.

What I have built is something that complements sendme, Started with their CLI tool fork, made it into a Tauri desktop application with very simple but modern UI (yes, I have read https://news.ycombinator.com/item?id=45760878, coincidence I guess)

Altsendme has almost all the features that sendme offers plus it is interoperable with sendme CLI tool.

Thank you.

This is a free, no signup desktop app that uses the clis like claude code, codex, gemini that are there in your system. It is less than 25mb for mac, linux, windows. Reason to start this: I had seen plenty of youtube videos where there "Cursor for marketers" or twitter threads on how to use claude code for managers or non-technical people in general. So I set out to make an editor that is preview first and that supports pptx, docx, csv, xlsx, markdown -- view, edit, and also interact with AI. And pdf, image, video with preview support. I wanted this to be one place for managers or people who work with multiple different file types. This is just the first alpha version of the product. Hope to get some feedback and thoughts so I could improve the product.

I’ve been working on this over the past few months after getting frustrated with how fragmented hardware workflows can be - switching between code editors, terminals, and toolchains.

Embedr is an AI-native IDE for Arduino and other hardware ecosystems. It helps you code, build, and flash your projects while integrating tightly with the underlying toolchains like the Arduino CLI. The goal is to make hardware development feel as seamless as modern software IDEs.

A key feature is the Embedr Agent, which works like Claude Code inside the IDE. You can describe what you want to build in natural language, and it assists with code generation, debugging, and project setup directly in your workspace.

Current version includes:

- Arduino CLI integration with board detection and flashing - Embedr Agent for AI-assisted development - Built-in terminal and serial monitor - Extensible plugin system for other toolchains (ESP-IDF, STM32, Raspberry Pi, etc.)

You can try it here: https://embedr.app

Still early, and I’d love to get feedback from folks who work with Arduino or embedded systems - what’s missing, what could be better, or what would make this truly useful day-to-day.

Hi everyone,

I built NatChecker – a free online tool that helps users easily check their network’s NAT type with one click, no login or setup required.

Many gamers and developers who use peer-to-peer (P2P) networking need to know their NAT type — for example, when hosting multiplayer games or running PCDN (peer-to-peer content delivery). A good NAT type (like Full Cone / NAT1 / NAT2) makes it easier to connect or host, while stricter types (Symmetric / NAT3) can block connections.

The tool runs entirely in your browser using WebRTC and public STUN servers, without collecting any data or requiring an account. My goal was to make NAT detection simple, private, and instant.

Feedback and suggestions are very welcome — especially if you have ideas to make the detection more accurate or faster!

I built an MCP server that lets Claude (and other AI assistants) fetch and summarize tech news.

It aggregates 20+ feeds including Hacker News, GitHub Trending, Techmeme, Reddit /r/technology, and more. When you ask Claude to "fetch latest news", it pulls all articles, extracts key topics, and generates summaries organized by feed.

The server is built with Next.js and uses the xmcp framework. You can run it locally or use the hosted version at https://infomate.online/mcp

Demo: Just ask Claude "fetch latest news" and get summaries like:

  - TypeScript overtook Python on GitHub
  - Reddit Q3 revenue up 68% YoY
  - OpenAI announced Aardvark security researcher
  - SpaceX Moon missions update
  

Source: https://github.com/agudulin/infomate-mcp

Durbat is a Rust procedural macro that enables writing Rust using Black Speech keywords, identifiers, and module paths. It maps Black Speech constructs to their Rust equivalents while remaining fully interoperable with standard Rust.