🛠️ Hacker News Tools

[Other] Show HN: Open-Source 8-Ch BCI Board (ESP32 and ADS1299 and OpenBCI GUI) Hi HN, I recently shared this on r&#x2F;BCI and wanted to see what the engineering community here thinks.<p>A while back, I got frustrated with the state of accessible BCI hardware. Research gear was wildly unaffordable. So, I spent a ton of time designing a custom board, software and firmware to bridge that gap. I call it the Cerelog ESP-EEG. It is open-source (Firmware + Schematics), and I designed it specifically to fix the signal integrity issues found in most DIY hardware.<p>I believe in sharing the work. You can find the Schematics, Firmware, and Software setup on the GitHub repo: GITHUB LINK: <a href="https:&#x2F;&#x2F;github.com&#x2F;Cerelog-ESP-EEG&#x2F;ESP-EEG" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;Cerelog-ESP-EEG&#x2F;ESP-EEG</a><p>For those who don&#x27;t want to deal with BGA soldering or sourcing components, I do have assembled units available: <a href="https:&#x2F;&#x2F;www.cerelog.com&#x2F;eeg_researchers.html" rel="nofollow">https:&#x2F;&#x2F;www.cerelog.com&#x2F;eeg_researchers.html</a><p>The major features: Forked&#x2F;modified OpenBCI GUI Compatibility as well as Brainflow API, and LSL Compatibility. I know a lot of us rely on the OpenBCI GUI for visualization because it just works. I didn&#x27;t want to reinvent the wheel, so I ensured this board supports it natively.<p>It works out of the box: I maintain a forked modified version of the GUI that connects to the board via LSL (Lab Streaming Layer). Zero coding required: You can visualize FFTs, Spectrograms, and EMG widgets immediately without writing a single line of Python.<p>The &quot;active bias&quot; (why my signal is cleaner): The TI ADS1299 is the gold standard for EEG, but many dev boards implement it incorrectly. They often leave the Bias feedback loop &quot;open&quot; (passive), which makes them terrible at rejecting 60Hz mains hum. I simply followed the datasheet: I implemented a True Closed-Loop Active Bias (Drive Right Leg).<p>How it works: It measures the common-mode signal, inverts it, and actively drives it back into the body. The result: Cleaner data<p>Tech stack:<p><pre><code> ADC: TI ADS1299 (24-bit, 8-channel). MCU: ESP32 Chosen to handle high-speed SPI and WiFi&#x2F;USB streaming Software: BrainFlow support (Python, C++, Java, C#) for those who want to build custom ML pipelines, LSL support, and forked version of OpenBCI GUI support </code></pre> This was a huge project for me. I’m happy to geek out about getting the ESP32 to stream reliably at high sample rates as both the software and firmware for this project proved a lot more challenging than I expected. Let me know what you think!<p>SAFETY NOTE: I strongly recommend running this on a LiPo battery via WiFi. If you must use USB, please use a laptop running on battery power, not plugged into the wall.

[Other] Show HN: OSS sustain guard – Sustainability signals for OSS dependencies Hi HN, I made OSS Sustain Guard.<p>After every high-profile OSS incident, I wonder about the packages I rely on right now. I can skim issues&#x2F;PRs and activity on GitHub, but that doesn’t scale when you have tens or hundreds of dependencies. I built this to surface sustainability signals (maintainer redundancy, activity trends, funding links, etc.) and create awareness. It’s meant to start a respectful conversation, not to judge projects. These are signals, not truth; everything is inferred from public data (internal mirrors&#x2F;private work won’t show up).<p>Quick start: pip install oss-sustain-guard export GITHUB_TOKEN=... os4g check<p>It uses GitHub GraphQL with local caching (no telemetry; token not uploaded&#x2F;stored), and supports multiple ecosystems (Python&#x2F;JS&#x2F;Rust&#x2F;Go&#x2F;Java&#x2F;etc.).<p>Repo: <a href="https:&#x2F;&#x2F;github.com&#x2F;onukura&#x2F;oss-sustain-guard" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;onukura&#x2F;oss-sustain-guard</a><p>I’d love feedback on metric choices&#x2F;thresholds and wording that stays respectful. If you have examples where these signals break down, please share.

[Other] I switched from VSCode to Zed

[Code Quality] Building a Rust-style static analyzer for C++ with AI

[Other] Show HN: An LLM-Powered PCB Schematic Checker (Major Update) Traceformer.io is a web application that ingests KiCad projects or Altium netlists along with relevant datasheets, enabling LLM-based schematic review. The system is designed to identify datasheet-driven schematic issues that traditional ERC tools can&#x27;t detect.<p>Since our first launch (formerly as Netlist.io), we&#x27;ve made some big changes:<p>- Full KiCad project parsing via an open-source plugin<p>- Pass-through API pricing with a small platform fee<p>- Automatic datasheet retrieval<p>- ERC&#x2F;DRC-style review UI<p>- Revamped review workflow with selectable frontier models (GPT 5.2, Opus 4.5, and more)<p>- Configurable review parameters (token limits, design rules, and parallel reviews)<p>Additionally, we continue to offer a free plan which lets you evaluate a design before subscribing. We&#x27;re looking forward to hearing your feedback!

[Other] OpenGitOps

[Other] Show HN: Terminal UI for AWS

[Other] Show HN: I made R/place for LLMs I built AI Place, a vLLM-controlled pixel canvas inspired by r&#x2F;place. Instead of users placing pixels, an LLM paints the grid continuously and you can watch it evolve live.<p>The theme rotates daily. Currently, the canvas is scored using CLIP ViT-B&#x2F;32 against a prompt (e.g., Pixelart of ${theme}). The highest-scoring snapshot is saved to the archive at the end of each day.<p>The agents work in a simple loop:<p>Input: Theme + image of current canvas<p>Output: Python code to update specific pixel coordinates + One word description<p>Tech: Next.js, SSE realtime updates, NVIDIA NIM (Mistral Large 3&#x2F;GPT-OSS&#x2F;Llama 4 Maverick) for the painting decisions<p>Would love feedback! (or ideas for prompts&#x2F;behaviors to try)

[IDE/Editor] Show HN: Hover – IDE style hover documentation on any webpage I thought it would be interesting to have ID style hover docs outside the IDE.<p>Hover is a Chrome extension that gives you IDE style hover tooltips on any webpage: documentation sites, ChatGPT, Claude, etc.<p>How it works: - When a code block comes into view, the extension detects tokens and sends the code to an LLM (via OpenRouter or custom endpoint) - The LLM generates documentation for tokens worth documenting, which gets cached - On hover, the cached documentation is displayed instantly<p>A few things I wanted to get right: - Website permissions are granular and use Chrome&#x27;s permission system, so the extension only runs where you allow it - Custom endpoints let you skip OpenRouter entirely – if you&#x27;re at a company with its own infra, you can point it at AWS Bedrock, Google AI Studio, or whatever you have<p>Built with TypeScript, Vite, and the Chrome extension APIs. Coming to the Chrome Web Store soon.<p>Would love feedback on the onboarding experience and general UX – there were a lot of design decisions I wasn&#x27;t sure about.<p>Happy to answer questions about the implementation.

[Other] Show HN: An interactive guide to how browsers work

[Other] Show HN: Rails-like web framework for Go Over the past couple of months I have been working on my own framework the encapsulates how I have come to build web apps using Go.<p>The aim is to make it faster and easier to build full-stack web applications that fully embraces hypermedia instead of JSON data API backend + SPA fronted<p>It&#x27;s getting close to a v1-beta release but the core structure and functionality is there.<p>Would love to hear hn&#x27;s thoughts!

[Other] Show HN: I built an HTTP/2 server in C++ to learn the protocol and language I wanted to learn more about the HTTP&#x2F;2 protocol but also deep dive into modern C++ development. I&#x27;m currently using it to host my personal web site - <a href="https:&#x2F;&#x2F;www.roberthargreaves.com" rel="nofollow">https:&#x2F;&#x2F;www.roberthargreaves.com</a>.<p>I&#x27;ve also blogged a bit about the development process, hosting options and steps I took to harden the application against attack - <a href="https:&#x2F;&#x2F;blog.roberthargreaves.com&#x2F;2026&#x2F;01&#x2F;03&#x2F;building-hosting-ion-http2-server" rel="nofollow">https:&#x2F;&#x2F;blog.roberthargreaves.com&#x2F;2026&#x2F;01&#x2F;03&#x2F;building-hostin...</a><p>It&#x27;s by no means a complete implementation of HTTP&#x2F;2, but I think I&#x27;ve achieved the main aims I was hoping to achieve with it!<p>I would love some feedback though from more experienced folks if there&#x27;s some egregious failings which I should address.

[Other] Show HN: Comet MCP – Give Claude Code a browser that can click Hey HN,<p>Claude Code is pretty agentic now. It writes scripts, calls APIs, uses CLIs. But when something requires actually clicking through a website, it stops and asks me to do it.<p>Problem is, I&#x27;m often unfamiliar with these platforms myself. &quot;Go to App Store Connect and generate a P8 key&quot; okay but where? I end up spending 10 minutes navigating menus I&#x27;ve never seen before.<p>I started delegating these tasks to Perplexity&#x27;s Comet browser. It handles the clicking, returns what I need. But copy-pasting between Claude and Comet got old fast.<p>So I built this MCP server to connect them directly. Now when Claude needs to interact with a website that has no API, it can just ask Comet to handle it.<p><pre><code> Examples: - Grab my app ID from RevenueCat dashboard - Generate a P8 key in App Store Connect - Navigate admin panels behind login walls </code></pre> I tried Playwright MCP but having Claude do the clicking itself overwhelms the context window. Comet&#x27;s agentic browsing just works better in my experience.<p>Comet doesn&#x27;t have an API, so this uses CDP to communicate with it directly.

[Other] Show HN: Self-hosted email server for 2026 – single binary, CalDAV Built this after getting frustrated with the paying to a google for email. Now running it for 1 months in production.<p>What it does: - Full SMTP server (inbound&#x2F;outbound, DKIM signing, SPF&#x2F;DMARC checking) - IMAP with IDLE support - CalDAV&#x2F;CardDAV (replace Google Calendar&#x2F;Contacts) - Web admin panel with Prometheus metrics - Greylisting for spam prevention - Auto-discovery (mail clients configure themselves) - Audit logging for compliance<p>What it doesn&#x27;t do: - Webmail (use Roundcube, etc.) - ML-based spam filtering (greylisting + basic heuristics only) - Clustering&#x2F;HA

[Other] Show HN: Vibe Coding a static site on a $25 Walmart Phone Hi! I took a cheap $25 walmart phone and put a static server on it? Why? Just for a fun weekend project.<p>I used Claude Code for most of the setup. I had a blast.<p>It&#x27;s running termux, andronix, nginx, cloudflared and even a prometheus node exporter.<p>Here&#x27;s the site:<p><a href="https:&#x2F;&#x2F;walmartphone.stetsonblake.com&#x2F;" rel="nofollow">https:&#x2F;&#x2F;walmartphone.stetsonblake.com&#x2F;</a>

[Other] Show HN: Open database of link metadata for large-scale analysis

[DevOps] Show HN: Offline tiles and routing and geocoding in one Docker Compose stack Hi HN,<p>I’m building Corviont, a self-hosted offline maps appliance (tiles + routing + search) for edge&#x2F;on-prem devices.<p>Hosted demo (no install): <a href="https:&#x2F;&#x2F;demo.corviont.com&#x2F;" rel="nofollow">https:&#x2F;&#x2F;demo.corviont.com&#x2F;</a><p>Self-host (Docker Compose repo): <a href="https:&#x2F;&#x2F;github.com&#x2F;corviont&#x2F;monaco-demo" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;corviont&#x2F;monaco-demo</a><p>Docs: <a href="https:&#x2F;&#x2F;www.corviont.com&#x2F;docs" rel="nofollow">https:&#x2F;&#x2F;www.corviont.com&#x2F;docs</a><p>What’s inside:<p><pre><code> - Vector tiles served locally (PMTiles) - Routing served locally (Valhalla) - Offline geocoding&#x2F;search + reverse (SQLite Nominatim-based index) - MapLibre UI wired to the local endpoints </code></pre> After the initial image + data pulls, it runs fully offline (no external map&#x2F;routing&#x2F;geocoding API calls).<p>Next (if people need it): a signed on-device updater for regional datasets (verify → atomic swap → reload).<p>I’d love feedback: where offline maps&#x2F;routing&#x2F;search matters for you, and what constraints bite (hardware, fleet size, update windows, regions, deployment style).

[Code Quality] Show HN: FP-pack – Functional pipelines in TypeScript without monads Hi HN,<p>I built fp-pack, a small TypeScript functional utility library focused on pipe-first composition.<p>The goal is to keep pipelines simple and readable, while still supporting early exits and side effects — without introducing monads like Option or Either.<p>Most code uses plain pipe&#x2F;pipeAsync. For the few cases that need early termination, fp-pack provides a SideEffect-based pipeline that short-circuits safely.<p>I also wrote an “AI agent skills” document to help LLMs generate consistent fp-pack-style code.<p>Feedback, criticism, or questions are very welcome.

[Other] Show HN: A small web app where people appear on a world map I&#x27;ve moved around a lot. Finding information is easy. Finding people is weirdly hard.<p>So I made this — a map where you drop a pin and see who else is around.<p>Filter by digital nomads, freelancers, remote workers, retirees. See if they just arrived or have been there for years.<p>Spot someone interesting? Send a message.<p>No signup. No feed. No tracking. No algorithm. Just a map.<p>More like exploring than scrolling.<p>Built with Next.js, Supabase, and Leaflet.

[Other] Show HN: Go-Highway – Portable SIMD for Go Go 1.26 adds native SIMD via GOEXPERIMENT=simd. This library provides a portability layer so the same code runs on AVX2, AVX-512, or falls back to scalar.<p>Inspired by Google&#x27;s Highway C++ library.<p>Includes vectorized math (exp, log, sin, tanh, sigmoid, erf) since those come up a lot in ML&#x2F;scientific code and the stdlib doesn&#x27;t have SIMD versions.<p>algo.SigmoidTransform(input, output)<p>Requires go1.26rc1. Feedback welcome.