I made a crossword app for language learners
Hi HN! In the last couple of weeks I've been working on Cranki: Cranki = Crosswords + Anki. (It's a stupid name tbh, haha) I like doing crosswords in Spanish (to learn vocab) but none of the apps out there allowed me to use my own list of words that I come across. So I built one instead. It's entirely client-side. No server, no database, no accounts, etc. Your words and stats are stored in local storage. I built this for myself but let me know if you like it!
I built a 2-min quiz that shows you how bad you are at estimating
I've gotten to the point in my career where I now make strategic decisions often (hiring, firing, choosing what equipment to go with, etc.), as well as in my personal life where I need to strongly weigh my options for a big purchase or investment. I found a not-so-surprising parallel between the two as these decisions "resolved." Am I making good decisions or am I getting lucky? Did some research, read some books, and realized I should get in the habit of tracking my decision process. That quickly turned into the idea that formed Convexly. The landing page is a 10-question calibration quiz where you assign a confidence level to statements drawn from a rotating pool of 100 (working on making the pool larger) and you get a Brier score back instantly. No signup required, and you can share your scores right away. If you find it interesting, you can create a free account where you can track your decisions with probability estimates, resolve them over time, and get calibration curves that show if you are over/underconfident. From what I've seen so far, users are overconfident when they say they're between 70-90% sure about something. For the math: Beta-PERT distributions for the payoff modeling, Kelly criterion for the position sizing, signal detection theory for separating skill from randomness. On the coding side: FastAPI with NumPy/SciPy, frontend in Next.js and Supabase. So far this has been a solo project of mine. If you want to see all the features use code SHOWHN for 30 days of full access, no credit card required. Curious if anything about your score surprised you after taking the quiz.
Is Hormuz open yet?
I built this because I was interested in the data. Didn't fully get it to what I wanted, but thought I'd share it nonetheless. Maybe someone has better data sources they could share! Turns out live ship tracking APIs are expensive so I manually just copied the json from https://www.marinetraffic.com/en/ais/home/centerx:57.4/cente... I'll probably have an ai agent do the same thing on some cron interval, if this gets any fanfare. To actually know if the port is open without live ship tracking I found https://portwatch.imf.org/pages/cb5856222a5b4105adc6ee7e880a... which was perfect, except it has 4 day lag! I also thought of adding news feed parsing or prediction market data to get a more definitive answer on if it's open right when you load it, but I spent a few hours and am gonna move on for now.
We built an AI Agent to reproduce bugs
At Metabase, we built an AI agent called Repro-Bot that reads our GitHub issues and attempts to reproduce reported bugs automatically. It started as a hackathon project and is now part of our daily workflow, so we wrote about it and open-sourced the code as an example for others. How have similar tools been working for you? What has worked well and what has not?
Solyto
Show HN: Solyto – a free, open-source all-in-one personal management app
A lightweight way to make agents talk without paying for API usage
Show HN: A lightweight way to make agents talk without paying for API usage
Graph Compose
Hey HN. Graph Compose is a hosted platform for orchestrating API workflows on Temporal. You define workflows as graphs of nodes (HTTP calls, AI agents, iterators, error boundaries) and everything runs as a durable Temporal workflow under the hood. Three ways to build the same graph: a React Flow visual builder, a typed TypeScript SDK (@graph-compose/client), and an AI assistant that turns plain English into a graph. Open-core: the execution foundations and integrations service are AGPL-3.0. The platform orchestrator, visual builder, and AI assistant are proprietary. Longer backstory on why I built this in the first comment. Would love feedback, especially from anyone who's dealt with the "services work fine, the glue between them doesn't" problem. Docs: https://graphcompose.io/docs
Spectrum
how can we make AI agents more accessible? it has been a crazy journey seeing how AI agents gets smarter every single day but interaction layer is still missing we are launching Spectrum TODAY: one Unified API connect your AI Agents into iMessage, WhatsApp, Telegram and more
Physics-accurate 3D assets for robotics simulations from any input
In the past 4 years, we developed a platform generating 3D visuals and deploying AR Try-on experiences into large footwear and retail companies. We focused on high-fidelity meshes and textures since the point was giving shoppers a realistic visual. Then robotics companies started to approach us and they asked for thousands of 3D assets that they can use in creating different simulation environments. This is crucial for them so they can achieve better sim-to-real transfer with domain randomization (train a humanoid in a million different kitchens so a real one is not a surprise when it is deployed in the real world). However, we realized nice geometry and pretty textures are not enough for sim engines as they lack physics properties. So we developed a new pipeline creating SimReady assets in OpenUSD and MJCF that plug directly into Isaac Sim and MuJoCo. - Mass: volume from the mesh, density from material classification by a vision-language model (approach adapted from NeRF2Physics), multiplied together. - Center of mass, static/dynamic friction coefficients and restitution from the same material classification and estimation priors. - Collision meshes via CoACD; adaptive hull count is in progress. - Geometry and texture optimization, plus file format conversions. - We are currently focused on physics property estimation for props. Next step: articulated objects It comes with free credits on easy Google sign-up so you can give it a test. No credit cards required. Still early. All we'd ask is honest feedback. What works, what doesn't, what you wish it did differently. That's worth more to us than anything right now.
Tiao, A two-player turn-based board game
Hi HN, I built this digital version of Tiao, a two-player turn based strategy board game. Think Checkers meets Go. It's free, runs in the browser, has multiplayer, AI, over the board mode and a lot of other neat things. The source is on GitHub (AGPL). The game was originally designed by my friend Andreas Edmeier. He created the rules and has been playtesting and refining the game design for years. I built the website for it. The core in about 2 weeks using TypeScript, Next.js, Express, Websockets, and MongoDB. Fully dockerized, deployed on a Hetzner VPS with Coolify. Authentication with better-auth. Real-time gameplay, ELO matchmaking, OpenPanel analytics, and a fully functional achievements system. Play it: https://playtiao.com Source: https://github.com/trebeljahr/tiao Happy to answer questions about the tech, the game design, or anything else. My hope is that more people will play this game because I think it is genuinely fun and would be cool to one day see people play this on a Go board or on their phones/computers. Have a good one.
Utilyze
The standard GPU utilization metric reported by nvidia-smi, nvtop, Weights & Biases, Amazon CloudWatch, Google Cloud Monitoring, and Azure Monitor is highly misleading. It reports the fraction of time that any kernel is running on the GPU, which means a GPU can report 100% utilization even if only a small portion of its compute capacity is actually being used. In practice, we've seen workloads with ~1–10% real compute throughput while dashboards show 100%. This becomes a problem when teams rely on that metric for capacity planning or optimization decisions, it can make underutilized systems look saturated. We're releasing an open-source (Apache 2.0) tool, Utilyze, to measure GPU utilization differently. It samples hardware performance counters and reports compute and memory throughput relative to the hardware's theoretical limits. It also estimates an attainable utilization ceiling for a given workload. GitHub link: https://github.com/systalyze/utilyze We'd love to hear your thoughts!
zot
Why I Built Another coding agent harness?: https://dev.to/patriceckhart/zot-why-i-built-another-coding-... Github Repo: https://github.com/patriceckhart/zot