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Show HN: Knock-Knock.net – Visualizing the bots knocking on my server's door

Show HN: Sameshi – a ~1200 Elo chess engine that fits within 2KB

I made a chess engine today, and made it fit within 2KB. I used a variant of MinMax called Negamax, with alpha beta pruning. For the board representation I have used a 120-cell "mailbox". I managed to squeeze in checkmate/stalemate in there, after trimming out some edge cases.<p>I am a great fan of demoscene (computer art subculture) since middle school, and hence it was a ritual i had to perform.<p>For estimating the Elo, I measured 240 automated games against Stockfish Elo levels (1320 to 1600) under fixed depth-5 and some constrained rules, using equal color distribution.<p>Then converted pooled win/draw/loss scores to Elo through some standard logistic formula with binomial 95% confidence interval.

Show HN: I spent 3 years reverse-engineering a 40 yo stock market sim from 1986

Hello my name is Ben Ward for the past 3 years I have been remastering the financial game Wall Street Raider created by Michael Jenkins originally on DOS in 1986.<p>It has been a rough journey but I finally see the light at the end of the tunnel. I just recently redid the website and thought maybe the full story of how this project came to be would interest you all. Thank you for reading.

Show HN: Data Engineering Book – An open source, community-driven guide

Hi HN! I'm currently a Master's student at USTC (University of Science and Technology of China). I've been diving deep into Data Engineering, especially in the context of Large Language Models (LLMs).<p>The Problem: I found that learning resources for modern data engineering are often fragmented and scattered across hundreds of medium articles or disjointed tutorials. It's hard to piece everything together into a coherent system.<p>The Solution: I decided to open-source my learning notes and build them into a structured book. My goal is to help developers fast-track their learning curve.<p>Key Features:<p>LLM-Centric: Focuses on data pipelines specifically designed for LLM training and RAG systems.<p>Scenario-Based: Instead of just listing tools, I compare different methods/architectures based on specific business scenarios (e.g., "When to use Vector DB vs. Keyword Search").<p>Hands-on Projects: Includes full code for real-world implementations, not just "Hello World" examples.<p>This is a work in progress, and I'm treating it as "Book-as-Code". I would love to hear your feedback on the roadmap or any "anti-patterns" I might have included!<p>Check it out:<p>Online: <a href="https://datascale-ai.github.io/data_engineering_book/" rel="nofollow">https://datascale-ai.github.io/data_engineering_book/</a><p>GitHub: <a href="https://github.com/datascale-ai/data_engineering_book" rel="nofollow">https://github.com/datascale-ai/data_engineering_book</a>

Show HN: AI agents play SimCity through a REST API

This is a weekend project that spiraled out of control. I was originally trying to get Claude to play a ROM of the SNES SimCity. I struggled with it and that led me to Micropolis (the open-sourced SimCity engine) and was able to get it to work by bolting on an API.<p>The weekend hack turned into a headless city simulation platform where anyone can get an API key (no signup) and have their AI agent play mayor. The simulation runs the real Micropolis engine inside Cloudflare Durable Objects, one per city. Every city is public and browsable on the site.<p>LLMs are awful at the spatial stuff, which sort of makes it extra fun as you try to control them when they scatter buildings randomly and struggle with power lines and roads. A little like dealing with a toddler.<p>There's a full REST API and an MCP server, so you can point Claude Code or Cursor at it directly. You can usually get agents building in seconds.<p>Website: <a href="https://hallucinatingsplines.com" rel="nofollow">https://hallucinatingsplines.com</a><p>API docs: <a href="https://hallucinatingsplines.com/docs" rel="nofollow">https://hallucinatingsplines.com/docs</a><p>GitHub: <a href="https://github.com/andrewedunn/hallucinating-splines" rel="nofollow">https://github.com/andrewedunn/hallucinating-splines</a><p>Future ideas: Let multiple agents play a single city and see how they step all over each other, or a "conquest mode" where you can earn points and spawn disasters on other cities.

Show HN: I built a macOS tool for network engineers – it's called NetViews

Hi HN — I’m the developer of NetViews, a macOS utility I built because I wanted better visibility into what was actually happening on my wired and wireless networks.<p>I live in the CLI, but for discovery and ongoing monitoring, I kept bouncing between tools, terminals, and mental context switches. I wanted something faster and more visual, without losing technical depth — so I built a GUI that brings my favorite diagnostics together in one place.<p>About three months ago, I shared an early version here and got a ton of great feedback. I listened: a new name (it was PingStalker), a longer trial, and a lot of new features. Today I’m excited to share NetViews 2.3.<p>NetViews started because I wanted to know if something on the network was scanning my machine. Once I had that, I wanted quick access to core details—external IP, Wi-Fi data, and local topology. Then I wanted more: fast, reliable scans using ARP tables and ICMP.<p>As a Wi-Fi engineer, I couldn’t stop there. I kept adding ways to surface what’s actually going on behind the scenes.<p>Discovery & Scanning: * ARP, ICMP, mDNS, and DNS discovery to enumerate every device on your subnet (IP, MAC, vendor, open ports). * Fast scans using ARP tables first, then ICMP, to avoid the usual “nmap wait”.<p>Wireless Visibility: * Detailed Wi-Fi connection performance and signal data. * Visual and audible tools to quickly locate the access point you’re associated with.<p>Monitoring & Timelines: * Connection and ping timelines over 1, 2, 4, or 8 hours. * Continuous “live ping” monitoring to visualize latency spikes, packet loss, and reconnects.<p>Low-level Traffic (but only what matters): * Live capture of DHCP, ARP, 802.1X, LLDP/CDP, ICMP, and off-subnet chatter. * mDNS decoded into human-readable output (this took months of deep dives).<p>Under the hood, it’s written in Swift. It uses low-level BSD sockets for ICMP and ARP, Apple’s Network framework for interface enumeration, and selectively wraps existing command-line tools where they’re still the best option. The focus has been on speed and low overhead.<p>I’d love feedback from anyone who builds or uses network diagnostic tools: - Does this fill a gap you’ve personally hit on macOS? - Are there better approaches to scan speed or event visualization that you’ve used? - What diagnostics do you still find yourself dropping to the CLI for?<p>Details and screenshots: <a href="https://netviews.app" rel="nofollow">https://netviews.app</a> There’s a free trial and paid licenses; I’m funding development directly rather than ads or subscriptions. Licenses include free upgrades.<p>Happy to answer any technical questions about the implementation, Swift APIs, or macOS permission model.

Show HN: Algorithmically finding the longest line of sight on Earth

We're Tom and Ryan and we teamed up to build an algorithm with Rust and SIMD to exhaustively search for the longest line of sight on the planet. We can confirm that a previously speculated view between Pik Dankova in Kyrgyzstan and the Hindu Kush in China is indeed the longest, at 530km.<p>We go into all the details at <a href="https://alltheviews.world" rel="nofollow">https://alltheviews.world</a><p>And there's an interactive map with over 1 billion longest lines, covering the whole world at <a href="https://map.alltheviews.world" rel="nofollow">https://map.alltheviews.world</a> Just click on any point and it'll load its longest line of sight.<p>Some of you may remember Tom's post[1] from a few months ago about how to efficiently pack visibility tiles for computing the entire planet. Well now it's done. The compute run itself took 100s of AMD Turin cores, 100s of GBs of RAM, a few TBs of disk and 2 days of constant runtime on multiple machines.<p>If you are interested in the technical details, Ryan and I have written extensively about the algorithm and pipeline that got us here:<p>* Tom's blog post: <a href="https://tombh.co.uk/longest-line-of-sight" rel="nofollow">https://tombh.co.uk/longest-line-of-sight</a><p>* Ryan's technical breakdown: <a href="https://ryan.berge.rs/posts/total-viewshed-algorithm" rel="nofollow">https://ryan.berge.rs/posts/total-viewshed-algorithm</a><p>This was a labor of love and we hope it inspires you both technically and naturally, to get you out seeing some of these vast views for yourselves!<p>1. <a href="https://news.ycombinator.com/item?id=45485227">https://news.ycombinator.com/item?id=45485227</a>

Show HN: It took 4 years to sell my startup. I wrote a book about it

Show HN: I created a Mars colony RPG based on Kim Stanley Robinson’s Mars books

I built a desktop Mars colony survival game called Underhill, in homage to Kim Stanley Robinson's Mars trilogy. Land on Mars, build solar panels and greenhouses, and try not to pass out during dust storms. Eventually your colonists split into factions: Greens who want to terraform and Reds who want to preserve Mars.<p>There’s Chill Mode for players that just want to build & hang, and Conflict Mode that introduces the Red v. Green factions. Reds sabotage, the terrain slowly turns green as the world gets more terraformed.<p>Feedback welcome, especially on performance and gameplay!

Show HN: I created a Mars colony RPG based on Kim Stanley Robinson’s Mars books

I built a desktop Mars colony survival game called Underhill, in homage to Kim Stanley Robinson's Mars trilogy. Land on Mars, build solar panels and greenhouses, and try not to pass out during dust storms. Eventually your colonists split into factions: Greens who want to terraform and Reds who want to preserve Mars.<p>There’s Chill Mode for players that just want to build & hang, and Conflict Mode that introduces the Red v. Green factions. Reds sabotage, the terrain slowly turns green as the world gets more terraformed.<p>Feedback welcome, especially on performance and gameplay!

Show HN: LocalGPT – A local-first AI assistant in Rust with persistent memory

I built LocalGPT over 4 nights as a Rust reimagining of the OpenClaw assistant pattern (markdown-based persistent memory, autonomous heartbeat tasks, skills system).<p>It compiles to a single ~27MB binary — no Node.js, Docker, or Python required.<p>Key features:<p>- Persistent memory via markdown files (MEMORY, HEARTBEAT, SOUL markdown files) — compatible with OpenClaw's format - Full-text search (SQLite FTS5) + semantic search (local embeddings, no API key needed) - Autonomous heartbeat runner that checks tasks on a configurable interval - CLI + web interface + desktop GUI - Multi-provider: Anthropic, OpenAI, Ollama etc - Apache 2.0<p>Install: `cargo install localgpt`<p>I use it daily as a knowledge accumulator, research assistant, and autonomous task runner for my side projects. The memory compounds — every session makes the next one better.<p>GitHub: <a href="https://github.com/localgpt-app/localgpt" rel="nofollow">https://github.com/localgpt-app/localgpt</a> Website: <a href="https://localgpt.app" rel="nofollow">https://localgpt.app</a><p>Would love feedback on the architecture or feature ideas.

Show HN: LocalGPT – A local-first AI assistant in Rust with persistent memory

I built LocalGPT over 4 nights as a Rust reimagining of the OpenClaw assistant pattern (markdown-based persistent memory, autonomous heartbeat tasks, skills system).<p>It compiles to a single ~27MB binary — no Node.js, Docker, or Python required.<p>Key features:<p>- Persistent memory via markdown files (MEMORY, HEARTBEAT, SOUL markdown files) — compatible with OpenClaw's format - Full-text search (SQLite FTS5) + semantic search (local embeddings, no API key needed) - Autonomous heartbeat runner that checks tasks on a configurable interval - CLI + web interface + desktop GUI - Multi-provider: Anthropic, OpenAI, Ollama etc - Apache 2.0<p>Install: `cargo install localgpt`<p>I use it daily as a knowledge accumulator, research assistant, and autonomous task runner for my side projects. The memory compounds — every session makes the next one better.<p>GitHub: <a href="https://github.com/localgpt-app/localgpt" rel="nofollow">https://github.com/localgpt-app/localgpt</a> Website: <a href="https://localgpt.app" rel="nofollow">https://localgpt.app</a><p>Would love feedback on the architecture or feature ideas.

Show HN: Look Ma, No Linux: Shell, App Installer, Vi, Cc on ESP32-S3 / BreezyBox

Example repo: <a href="https://github.com/valdanylchuk/breezydemo" rel="nofollow">https://github.com/valdanylchuk/breezydemo</a><p>The underlying ESP-IDF component: <a href="https://github.com/valdanylchuk/breezybox" rel="nofollow">https://github.com/valdanylchuk/breezybox</a><p>It is something like Raspberry Pi, but without the overhead of a full server-grade OS.<p>It captures a lot of the old school DOS era coding experience. I created a custom fast text mode driver, plan to add VGA-like graphics next. ANSI text demos run smooth, as you can see in the demo video featured in the Readme.<p>App installs also work smoothly. The first time it installed 6 apps from my git repo with one command, felt like, "OMG, I got homebrew to run on a toaster!" And best of all, it can install from any repo, no approvals or waiting, you just publish a compatible ELF file in your release.<p>Coverage:<p>Hackaday: <a href="https://hackaday.com/2026/02/06/breezybox-a-busybox-like-shell-and-virtual-terminal-for-esp32/" rel="nofollow">https://hackaday.com/2026/02/06/breezybox-a-busybox-like-she...</a><p>Hackster.io: <a href="https://www.hackster.io/news/valentyn-danylchuk-s-breezybox-turns-an-espressif-esp32-s3-into-a-tiny-instant-on-pc-3d3135050df1" rel="nofollow">https://www.hackster.io/news/valentyn-danylchuk-s-breezybox-...</a><p>Reddit: <a href="https://www.reddit.com/r/esp32/comments/1qq503c/i_made_an_instanton_tiny_pc_based_on_esp32s3_with/" rel="nofollow">https://www.reddit.com/r/esp32/comments/1qq503c/i_made_an_in...</a>

Show HN: I spent 4 years building a UI design tool with only the features I use

Hello everyone!<p>I'm a solo developer who's been doing UI/UX work since 2007. Over the years, I watched design tools evolve from lightweight products into bloated feature-heavy platforms. I kept finding myself using a small amount of the features while the rest just mostly got in the way.<p>So a few years ago I set out to build a design tool just like I wanted. So I built Vecti with what I actually need: pixel-perfect grid snapping, a performant canvas renderer, shared asset libraries, and export/presentation features. No collaborative whiteboarding. No plugin ecosystem. No enterprise features. Just the design loop.<p>Four years later, I can proudly show it off. Built and hosted in the EU with European privacy regulations. Free tier available (no credit card, one editor forever).<p>On privacy: I use some basic analytics (page views, referrers) but zero tracking inside the app itself. No session recordings, no behavior analytics, no third-party scripts beyond the essentials.<p>If you're a solo designer or small team who wants a tool that stays out of your way, I'd genuinely appreciate your feedback: <a href="https://vecti.com" rel="nofollow">https://vecti.com</a><p>Happy to answer questions about the tech stack, architecture decisions, why certain features didn't make the cut, or what's next.

Show HN: If you lose your memory, how to regain access to your computer?

Due to bike-induced concussions, I've been worried for a while about losing my memory and not being able to log back in.<p>I combined shamir secret sharing (hashicorp vault's implementation) with age-encryption, and packaged it using WASM for a neat in-browser offline UX.<p>The idea is that if something happens to me, my friends and family would help me get back access to the data that matters most to me. 5 out of 7 friends need to agree for the vault to unlock.<p>Try out the demo in the website, it runs entirely in your browser!

Show HN: Ghidra MCP Server – 110 tools for AI-assisted reverse engineering

Show HN: Craftplan – I built my wife a production management tool for her bakery

My wife was planning to open a micro-bakery. We looked at production management software and it was all either expensive or way too generic. The actual workflows for a small-batch manufacturer aren't that complex, so I built one and open-sourced it.<p>Craftplan handles recipes (versioned BOMs with cost rollups), inventory (lot traceability, demand forecasting, allergen tracking), orders, production batch planning, and purchasing. Built with Elixir, Ash Framework, Phoenix LiveView, and PostgreSQL.<p>Live demo: <a href="https://craftplan.fly.dev" rel="nofollow">https://craftplan.fly.dev</a> (test@test.com / Aa123123123123)<p>GitHub: <a href="https://github.com/puemos/craftplan" rel="nofollow">https://github.com/puemos/craftplan</a>

Show HN: Wikipedia as a doomscrollable social media feed

Show HN: Wikipedia as a doomscrollable social media feed

Show HN: NanoClaw – “Clawdbot” in 500 lines of TS with Apple container isolation

I’ve been running Clawdbot for the last couple weeks and have genuinely found it useful but running it scares the crap out of me.<p>OpenClaw has 52+ modules and runs agents with near-unlimited permissions in a single Node process. NanoClaw is ~500 lines of core code, agents run in actual Apple containers with filesystem isolation. Each chat gets its own sandboxed context.<p>This is not a swiss army knife. It’s built to match my exact needs. Fork it and make it yours.