The best Hacker News stories from Show from the past day
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Show HN: Reconstruct any image using primitive shapes, runs in-browser via WASM
I built a browser-based port of fogleman/primitive — a Go CLI tool that approximates images using primitive shapes (triangles, ellipses, beziers, etc.) via a hill-climbing algorithm.
The original tool requires building from source and running from the terminal, which isn't exactly accessible. I compiled the core logic to WebAssembly so anyone can drop an image and watch it get reconstructed shape by shape, entirely client-side with no server involved.<p>Demo: <a href="https://primitive-playground.taiseiue.jp/" rel="nofollow">https://primitive-playground.taiseiue.jp/</a>
Source: <a href="https://github.com/taiseiue/primitive-playground" rel="nofollow">https://github.com/taiseiue/primitive-playground</a><p>Curious if anyone has ideas for shapes or features worth adding.
Show HN: A trainable, modular electronic nose for industrial use
Hi HN,<p>I’m part of the team building Sniphi.<p>Sniphi is a modular digital nose that uses gas sensors and machine-learning models to convert volatile organic compound (VOC) data into a machine-readable signal that can be integrated into existing QA, monitoring, or automation systems. The system is currently in an R&D phase, but already exists as working hardware and software and is being tested in real environments.<p>The project grew out of earlier collaborations with university researchers on gas sensors and odor classification. What we kept running into was a gap between promising lab results and systems that could actually be deployed, integrated, and maintained in real production environments.<p>One of our core goals was to avoid building a single-purpose device. The same hardware and software stack can be trained for different use cases by changing the training data and models, rather than the physical setup. In that sense, we think of it as a “universal” electronic nose: one platform, multiple smell-based tasks.<p>Some design principles we optimized for:<p>- Composable architecture: sensor ingestion, ML inference, and analytics are decoupled and exposed via APIs/events<p>- Deployment-first thinking: designed for rollout in factories and warehouses, not just controlled lab setups<p>- Cloud-backed operations: model management, monitoring, updates run on Azure, which makes it easier to integrate with existing industrial IT setups<p>- Trainable across use cases: the same platform can be retrained for different classification or monitoring tasks without redesigning the hardware<p>One public demo we show is classifying different coffee aromas, but that’s just a convenient example. In practice, we’re exploring use cases such as:<p>- Quality control and process monitoring<p>- Early detection of contamination or spoilage<p>- Continuous monitoring in large storage environments (e.g. detecting parasite-related grain contamination in warehouses)<p>Because this is a hardware system, there’s no simple way to try it over the internet. To make it concrete, we’ve shared:<p>- A short end-to-end demo video showing the system in action (YouTube)<p>- A technical overview of the architecture and deployment model: <a href="https://sniphi.com/" rel="nofollow">https://sniphi.com/</a><p>At this stage, we’re especially interested in feedback and conversations with people who:<p>- Have deployed physical sensors at scale<p>- Have run into problems that smell data <i>might</i> help with<p>- Are curious about piloting or testing something like this in practice<p>We’re not fundraising here. We’re mainly trying to learn where this kind of sensing is genuinely useful and where it isn’t.<p>Happy to answer technical questions.
Show HN: Claude-replay – A video-like player for Claude Code sessions
I got tired of sharing AI demos with terminal screenshots or screen recordings.<p>Claude Code already stores full session transcripts locally as JSONL files. Those logs contain everything: prompts, tool calls, thinking blocks, and timestamps.<p>I built a small CLI tool that converts those logs into an interactive HTML replay.<p>You can step through the session, jump through the timeline, expand tool calls, and inspect the full conversation.<p>The output is a single self-contained HTML file — no dependencies. You can email it, host it anywhere, embed it in a blog post, and it works on mobile.<p>Repo: <a href="https://github.com/es617/claude-replay" rel="nofollow">https://github.com/es617/claude-replay</a><p>Example replay: <a href="https://es617.github.io/assets/demos/peripheral-uart-demo.html" rel="nofollow">https://es617.github.io/assets/demos/peripheral-uart-demo.ht...</a>
Show HN: Swarm – Program a colony of 200 ants using a custom assembly language
We built an ant colony simulation as an internal hiring challenge at Moment and decided to open it up publicly.<p>You write a program in a custom assembly-like (we call it ant-ssembly) instruction set that controls 200 ants. Each ant can sense nearby cells (food, pheromones, home, other ants) but has no global view. The only coordination mechanism is pheromone trails, which ants can emit and sense them, but that's it. Your program runs identically on every ant.<p>The goal is to collect the highest percentage of food across a set of maps. Different map layouts (clustered food, scattered, obstacles) reward very different strategies. The leaderboard is live.<p>Grand prize is a trip to Maui for two paid for by Moment. Challenge closes March 12.<p>Curious what strategies people discover. We've seen some surprisingly clever emergent behavior internally.
Show HN: Moongate – Ultima Online server emulator in .NET 10 with Lua scripting
I've been building a modern Ultima Online server emulator from scratch. It's not feature-complete (no combat, no skills yet), but the foundation is solid and I wanted to share it early.<p>What it does today:
- Full packet layer for the classic UO client (login, movement, items, mobiles)
- Lua scripting for item behaviors (double-click a potion, open a door — all defined in Lua, no C# recompile)
- Spatial world partitioned into sectors with delta sync (only sends packets for new sectors when crossing boundaries)
- Snapshot-based persistence with MessagePack
- Source generators for automatic DI wiring, packet handler registration, and Lua module exposure
- NativeAOT support — the server compiles to a single native binary
- Embedded HTTP admin API + React management UI
- Auto-generated doors from map statics (same algorithm as ModernUO/RunUO)<p>Tech stack: .NET 10, NativeAOT, NLua, MessagePack, DryIoc, Kestrel<p>What's missing: Combat, skills, weather integration, NPC AI. This is still early — the focus so far has been on getting the architecture right so adding those systems doesn't require rewiring everything.<p>Why not just use ModernUO/RunUO? Those are mature and battle-tested. I started this because I wanted to rethink the architecture from scratch: strict network/domain separation, event-driven game loop, no
inheritance-heavy item hierarchies, and Lua for rapid iteration on game logic without recompiling.<p>GitHub: <a href="https://github.com/moongate-community/moongatev2" rel="nofollow">https://github.com/moongate-community/moongatev2</a>
Show HN: Moongate – Ultima Online server emulator in .NET 10 with Lua scripting
I've been building a modern Ultima Online server emulator from scratch. It's not feature-complete (no combat, no skills yet), but the foundation is solid and I wanted to share it early.<p>What it does today:
- Full packet layer for the classic UO client (login, movement, items, mobiles)
- Lua scripting for item behaviors (double-click a potion, open a door — all defined in Lua, no C# recompile)
- Spatial world partitioned into sectors with delta sync (only sends packets for new sectors when crossing boundaries)
- Snapshot-based persistence with MessagePack
- Source generators for automatic DI wiring, packet handler registration, and Lua module exposure
- NativeAOT support — the server compiles to a single native binary
- Embedded HTTP admin API + React management UI
- Auto-generated doors from map statics (same algorithm as ModernUO/RunUO)<p>Tech stack: .NET 10, NativeAOT, NLua, MessagePack, DryIoc, Kestrel<p>What's missing: Combat, skills, weather integration, NPC AI. This is still early — the focus so far has been on getting the architecture right so adding those systems doesn't require rewiring everything.<p>Why not just use ModernUO/RunUO? Those are mature and battle-tested. I started this because I wanted to rethink the architecture from scratch: strict network/domain separation, event-driven game loop, no
inheritance-heavy item hierarchies, and Lua for rapid iteration on game logic without recompiling.<p>GitHub: <a href="https://github.com/moongate-community/moongatev2" rel="nofollow">https://github.com/moongate-community/moongatev2</a>
Show HN: SitDeck – Customizable live dashboard of news, markets, threats
Show HN: SitDeck – Customizable live dashboard of news, markets, threats
Show HN: Qlog – grep for logs, but 100x faster
I built qlog because I got tired of waiting for grep to search through gigabytes of logs.<p>qlog uses an inverted index (like search engines) to search millions of log lines in milliseconds. It's 10-100x faster than grep and way simpler than setting up Elasticsearch.<p>Features:
- Lightning fast indexing (1M+ lines/sec using mmap)
- Sub-millisecond searches on indexed data
- Beautiful terminal output with context lines
- Auto-detects JSON, syslog, nginx, apache formats
- Zero configuration
- Works offline
- Pure Python<p>Example:
qlog index './logs/*/*.log'
qlog search "error" --context 3<p>I've tested it on 10GB of logs and it's consistently 3750x faster than grep. The index is stored locally so repeated searches are instant.<p>Demo: Run `bash examples/demo.sh` to see it in action.<p>GitHub: <a href="https://github.com/Cosm00/qlog" rel="nofollow">https://github.com/Cosm00/qlog</a><p>Perfect for developers/DevOps folks who search logs daily.<p>Happy to answer questions!
Show HN: A shell-native cd-compatible directory jumper using power-law frecency
I have used this tool privately since 2011 to manage directory jumping. While it
is conceptually similar to tools like z or zoxide, the underlying ranking model is
different. It uses a power-law convolution with the time series of cd actions to
calculate a history-aware "frecency" metric instead of the standard heuristic
counters and multipliers.<p>This approach moves away from point-estimates for recency. Most tools look only
at the timestamp of the last visit, which can allow a "one-off" burst of activity
to clobber long-term habits. By convolving a configurable history window
(typically the last 1,000+ events), the score balances consistent habits against
recent flukes.<p>On performance: Despite the O(N) complexity of calculating decay for 1,000+
events, query time is ~20-30ms (Real Time) in ksh/bash, which is well below the threshold of perceived lag.<p>I intentionally chose a Logical Path (pwd -L) model. Preserving symlink names
ensures that the "Name" remains the primary searchable key. Resolving to physical
paths often strips away the very keyword the user intends to use for searching.
Show HN: PageAgent, A GUI agent that lives inside your web app
Title: Show HN: PageAgent, A GUI agent that lives inside your web app<p>Hi HN,<p>I'm building PageAgent, an open-source (MIT) library that embeds an AI agent directly into your frontend.<p>I built this because I believe there's a massive design space for deploying general agents natively inside the web apps we already use, rather than treating the web merely as a dumb target for isolated bots.<p>Currently, most AI agents operate from external clients or server-side programs, effectively leaving web development out of the AI ecosystem. I'm experimenting with an "inside-out" paradigm instead. By dropping the library into a page, you get a client-side agent that interacts natively with the live DOM tree and inherits the user's active session out of the box, which works perfectly for SPAs.<p>To handle cross-page tasks, I built an optional browser extension that acts as a "bridge". This allows the web-page agent to control the entire browser with explicit user authorization. Instead of a desktop app controlling your browser, your web app is empowered to act as a general agent that can navigate the broader web.<p>I'd love to start a conversation about the viability of this architecture, and what you all think about the future of in-app general agents. Happy to answer any questions!
Show HN: PageAgent, A GUI agent that lives inside your web app
Title: Show HN: PageAgent, A GUI agent that lives inside your web app<p>Hi HN,<p>I'm building PageAgent, an open-source (MIT) library that embeds an AI agent directly into your frontend.<p>I built this because I believe there's a massive design space for deploying general agents natively inside the web apps we already use, rather than treating the web merely as a dumb target for isolated bots.<p>Currently, most AI agents operate from external clients or server-side programs, effectively leaving web development out of the AI ecosystem. I'm experimenting with an "inside-out" paradigm instead. By dropping the library into a page, you get a client-side agent that interacts natively with the live DOM tree and inherits the user's active session out of the box, which works perfectly for SPAs.<p>To handle cross-page tasks, I built an optional browser extension that acts as a "bridge". This allows the web-page agent to control the entire browser with explicit user authorization. Instead of a desktop app controlling your browser, your web app is empowered to act as a general agent that can navigate the broader web.<p>I'd love to start a conversation about the viability of this architecture, and what you all think about the future of in-app general agents. Happy to answer any questions!
Show HN: Poppy – A simple app to stay intentional with relationships
I built Poppy as a side project to help people keep in touch more intentionally. Would love feedback on onboarding, reminders, and overall UX. Happy to answer questions.
Show HN: Poppy – A simple app to stay intentional with relationships
I built Poppy as a side project to help people keep in touch more intentionally. Would love feedback on onboarding, reminders, and overall UX. Happy to answer questions.
Show HN: Jido 2.0, Elixir Agent Framework
Hi HN!<p>I'm the author of an Elixir Agent Framework called Jido. We reached our 2.0 release this week, shipping a production-hardened framework to build, manage and run Agents on the BEAM.<p>Jido now supports a host of Agentic features, including:<p>- Tool Calling and Agent Skills
- Comprehensive multi-agent support across distributed BEAM processes with Supervision
- Multiple reasoning strategies including ReAct, Chain of Thought, Tree of Thought, and more
- Advanced workflow capabilities
- Durability through a robust Storage and Persistence layer
- Agentic Memory
- MCP and Sensors to interface with external services
- Deep observability and debugging capabilities, including full stack OTel<p>I know Agent Frameworks can be considered a bit stale, but there hasn't been a major release of a framework on the BEAM. With a growing realization that the architecture of the BEAM is a good match for Agentic workloads, the time was right to make the announcement.<p>My background is enterprise engineering, distributed systems and Open Source. We've got a strong and growing community of builders committed to the Jido ecosystem. We're looking forward to what gets built on top of Jido!<p>Come build agents with us!
Show HN: Jido 2.0, Elixir Agent Framework
Hi HN!<p>I'm the author of an Elixir Agent Framework called Jido. We reached our 2.0 release this week, shipping a production-hardened framework to build, manage and run Agents on the BEAM.<p>Jido now supports a host of Agentic features, including:<p>- Tool Calling and Agent Skills
- Comprehensive multi-agent support across distributed BEAM processes with Supervision
- Multiple reasoning strategies including ReAct, Chain of Thought, Tree of Thought, and more
- Advanced workflow capabilities
- Durability through a robust Storage and Persistence layer
- Agentic Memory
- MCP and Sensors to interface with external services
- Deep observability and debugging capabilities, including full stack OTel<p>I know Agent Frameworks can be considered a bit stale, but there hasn't been a major release of a framework on the BEAM. With a growing realization that the architecture of the BEAM is a good match for Agentic workloads, the time was right to make the announcement.<p>My background is enterprise engineering, distributed systems and Open Source. We've got a strong and growing community of builders committed to the Jido ecosystem. We're looking forward to what gets built on top of Jido!<p>Come build agents with us!
Show HN: We want to displace Notion with collaborative Markdown files
Hi HN! We at Moment[1] are working on Notion alternative which is (1) rich and collaborative, but (2) also just plain-old Markdown files, stored in git (ok, technically in jj), on local disk. We think the era of rigid SaaS UI is, basically, over: coding agents (`claude`, `amp`, `copilot`, `opencode`, <i>etc</i>.) are good enough now that they instantly build custom UI that fits your needs exactly. The very best agents in the world are coding agents, and we want to allow people to simply use them, <i>e.g.</i>, to build little internal tools—but without compromising on collaboration.<p>Moment aims to cover this and other gaps: seamless collaborative editing for teams, more robust programming capabilities built in (including a from-scratch React integration), and tools for accessing private APIs.<p>A lot of our challenge is just in making the collaborative editing work really well. We have found this is a lot harder than simply slapping Yjs on the frontend and calling it a day. We wrote about this previously and the post[2] did pretty well on HN: Lies I was Told About Collaborative editing (352 upvotes as of this writing). Beyond that, in part 2, we'll talk about the reasons we found it hard to get collab to run at 60fps consistently—for one, the Yjs ProseMirror bindings completely tear down and re-create the entire document on every single collaborative keystroke.<p>We hope you will try it out! At this stage even negative feedback is helpful. :)<p>[1]: <a href="https://www.moment.dev/" rel="nofollow">https://www.moment.dev/</a><p>[2]: <a href="https://news.ycombinator.com/item?id=42343953">https://news.ycombinator.com/item?id=42343953</a>
Show HN: Effective Git
As many of us shift from being software engineers to software managers, tracking changes the right way is growing more important.<p>It’s time to truly understand and master Git.
Show HN: Explain Curl Commands
Show HN: I made a zero-copy coroutine tracer to find my scheduler's lost wakeups