The best Hacker News stories from Show from the past day
Latest posts:
Show HN: A store that generates products from anything you type in search
Show HN: A store that generates products from anything you type in search
Show HN: A store that generates products from anything you type in search
Show HN: A store that generates products from anything you type in search
Show HN: An MCP Gateway to block the lethal trifecta
Hi there, me and some friends were inspired by Simon Willison's recent post on the "lethal trifecta" (<a href="https://simonwillison.net/2025/Jun/16/the-lethal-trifecta/" rel="nofollow">https://simonwillison.net/2025/Jun/16/the-lethal-trifecta/</a> ) and started building a gateway to defend against it.<p>The idea: instead of connecting an LLM directly to multiple MCP servers, you point them all through a Gateway.<p>The Gateway:<p>- Connects to each MCP server and inspects their tools + requirements<p>- Classifies tools along the "trifecta" axes (private data access, untrusted content, external comms)<p>- When all three conditions are about to align in a single session, the Gateway blocks the last step and tells the LLM to show a warning instead.<p>That way, before anything dangerous can happen, the user is nudged to review the situation in a web dashboard.<p>We'd love for the HN community to try it out: <a href="https://github.com/Edison-Watch/open-edison" rel="nofollow">https://github.com/Edison-Watch/open-edison</a><p>Any feedback very welcome - we'll be around in the thread to answer questions.
Show HN: Aris – a free AI-powered answer engine for kids
I am Andrew, and I’m building Aris (<a href="https://www.aris.chat/" rel="nofollow">https://www.aris.chat/</a>).<p>Aris is a minimalist tool that answers any questions a child has.<p>Encyclopedias, periodicals, field guides, cookbooks, and other print resources we used as kids to find knowledge, learn, and pursue our curiosities have been replaced in most households by something that is not safe for kids: the internet. So instead, kids get Fortnite, Minecraft, and ‘edutainment’ options that don’t compare to the knowledge resources that past generations have had access to.<p>With this in mind, many of the smartest people I know raise (or plan to raise) their kids with access to only a 1990s level of consumer technology, without smartphones, tablets, social media, online gaming, etc. Many of these people believe the last three decades of technological development have been a net negative for kids. When my child was born, I had a similar sentiment. However, there are some major problems with limiting a kid’s access to technology today. To name a couple: 1.) a set of World Book encyclopedias now costs $1,200, and 2.) many print resources aren’t as good as they used to be, if they are even still in print, since the market changed. As parents, we need a safe, simple, nonaddictive way for kids to access and explore the world’s knowledge easily and independently.<p>Aris uses a combination of large language models with policy engines and web search tools to find relevant, timely answers to their questions and only returns the stripped-down answers. It does not return links for them to click on or images or advertisements. Parents can tune the moderation settings as finely as they’d like, preventing discussions about banned topics and even getting as specific as making sure Aris doesn’t tell their second child that Santa isn’t real.<p>The model context handling and system instructions are designed to prevent kids from building emotional reliance or relationships with it. Rather than trying to pull a child into the experience to maximize engagement, Aris is meant to gently redirect the child out of the device into the real world after their question has been answered.<p>We are available as a web app and iPhone/iPad app in the Apple App store, but we have also made our Apple Watch app available in the iOS store as well. We believe minimalist wearables are a good device substitute for younger humans, and we hope Aris can be a healthy addition to those wearables.<p>We plan to make money through premium features that include creating multiple child accounts, accessing premium models for better answers, and for ultra-high usage limits.<p>Come use the app for free on our website or by downloading it in the iOS store by searching for “Aris AI”. We’d love to hear your ideas, experiences, and feedback. Thanks!
Show HN: Aris – a free AI-powered answer engine for kids
I am Andrew, and I’m building Aris (<a href="https://www.aris.chat/" rel="nofollow">https://www.aris.chat/</a>).<p>Aris is a minimalist tool that answers any questions a child has.<p>Encyclopedias, periodicals, field guides, cookbooks, and other print resources we used as kids to find knowledge, learn, and pursue our curiosities have been replaced in most households by something that is not safe for kids: the internet. So instead, kids get Fortnite, Minecraft, and ‘edutainment’ options that don’t compare to the knowledge resources that past generations have had access to.<p>With this in mind, many of the smartest people I know raise (or plan to raise) their kids with access to only a 1990s level of consumer technology, without smartphones, tablets, social media, online gaming, etc. Many of these people believe the last three decades of technological development have been a net negative for kids. When my child was born, I had a similar sentiment. However, there are some major problems with limiting a kid’s access to technology today. To name a couple: 1.) a set of World Book encyclopedias now costs $1,200, and 2.) many print resources aren’t as good as they used to be, if they are even still in print, since the market changed. As parents, we need a safe, simple, nonaddictive way for kids to access and explore the world’s knowledge easily and independently.<p>Aris uses a combination of large language models with policy engines and web search tools to find relevant, timely answers to their questions and only returns the stripped-down answers. It does not return links for them to click on or images or advertisements. Parents can tune the moderation settings as finely as they’d like, preventing discussions about banned topics and even getting as specific as making sure Aris doesn’t tell their second child that Santa isn’t real.<p>The model context handling and system instructions are designed to prevent kids from building emotional reliance or relationships with it. Rather than trying to pull a child into the experience to maximize engagement, Aris is meant to gently redirect the child out of the device into the real world after their question has been answered.<p>We are available as a web app and iPhone/iPad app in the Apple App store, but we have also made our Apple Watch app available in the iOS store as well. We believe minimalist wearables are a good device substitute for younger humans, and we hope Aris can be a healthy addition to those wearables.<p>We plan to make money through premium features that include creating multiple child accounts, accessing premium models for better answers, and for ultra-high usage limits.<p>Come use the app for free on our website or by downloading it in the iOS store by searching for “Aris AI”. We’d love to hear your ideas, experiences, and feedback. Thanks!
Show HN: Aris – a free AI-powered answer engine for kids
I am Andrew, and I’m building Aris (<a href="https://www.aris.chat/" rel="nofollow">https://www.aris.chat/</a>).<p>Aris is a minimalist tool that answers any questions a child has.<p>Encyclopedias, periodicals, field guides, cookbooks, and other print resources we used as kids to find knowledge, learn, and pursue our curiosities have been replaced in most households by something that is not safe for kids: the internet. So instead, kids get Fortnite, Minecraft, and ‘edutainment’ options that don’t compare to the knowledge resources that past generations have had access to.<p>With this in mind, many of the smartest people I know raise (or plan to raise) their kids with access to only a 1990s level of consumer technology, without smartphones, tablets, social media, online gaming, etc. Many of these people believe the last three decades of technological development have been a net negative for kids. When my child was born, I had a similar sentiment. However, there are some major problems with limiting a kid’s access to technology today. To name a couple: 1.) a set of World Book encyclopedias now costs $1,200, and 2.) many print resources aren’t as good as they used to be, if they are even still in print, since the market changed. As parents, we need a safe, simple, nonaddictive way for kids to access and explore the world’s knowledge easily and independently.<p>Aris uses a combination of large language models with policy engines and web search tools to find relevant, timely answers to their questions and only returns the stripped-down answers. It does not return links for them to click on or images or advertisements. Parents can tune the moderation settings as finely as they’d like, preventing discussions about banned topics and even getting as specific as making sure Aris doesn’t tell their second child that Santa isn’t real.<p>The model context handling and system instructions are designed to prevent kids from building emotional reliance or relationships with it. Rather than trying to pull a child into the experience to maximize engagement, Aris is meant to gently redirect the child out of the device into the real world after their question has been answered.<p>We are available as a web app and iPhone/iPad app in the Apple App store, but we have also made our Apple Watch app available in the iOS store as well. We believe minimalist wearables are a good device substitute for younger humans, and we hope Aris can be a healthy addition to those wearables.<p>We plan to make money through premium features that include creating multiple child accounts, accessing premium models for better answers, and for ultra-high usage limits.<p>Come use the app for free on our website or by downloading it in the iOS store by searching for “Aris AI”. We’d love to hear your ideas, experiences, and feedback. Thanks!
Show HN: I made a small site to share text and files
Show HN: I made a small site to share text and files
Show HN: C++ Compiler Support Page
Hi HN,<p>I have created a webpage that displays all C++ features since C++20 in a simple, searchable table.<p>It is intended to serve as a quick reference for C++ developers, whether as support for cross-platform development or simply to track the current support status out of curiosity.<p>I created it as a simpler, more structured, and more up-to-date alternative to the cppreference compiler support site.
Please note that the page intentionally does not list LWG and CWG papers.
This might change as I am continually updating the site and trying out new ideas.<p>Questions, feedback and suggestions are appreciated, either here or in the form of GitHub issues.
Show HN: C++ Compiler Support Page
Hi HN,<p>I have created a webpage that displays all C++ features since C++20 in a simple, searchable table.<p>It is intended to serve as a quick reference for C++ developers, whether as support for cross-platform development or simply to track the current support status out of curiosity.<p>I created it as a simpler, more structured, and more up-to-date alternative to the cppreference compiler support site.
Please note that the page intentionally does not list LWG and CWG papers.
This might change as I am continually updating the site and trying out new ideas.<p>Questions, feedback and suggestions are appreciated, either here or in the form of GitHub issues.
Show HN: I made a generative online drum machine with ClojureScript
After two years of development, I'm super excited to release Beat Maker! This is my take on what I hope is the best free, web-based drum machine.<p>My goal was to build something that was not only fun and easy to use for beginners but also powerful enough for serious producers. I did extensive research on existing drum machines, analyzed their UX, and tried to build something that adds something new.<p>It's a nearly 100% client-side app, written in ClojureScript, and is a PWA so you can install it to your home screen for an app-like experience.<p>Besides the standard grid editor, Beat Maker has some unique features that I think HN readers might find interesting:<p>- Procedural sample generation. One annoying thing about writing beats is searching through folders full of samples. I wanted to improve this and so I added the ability to generate new samples with a single click, giving you an infinite supply of unique drum samples.
* Generative beat creation. If you're looking for inspiration, Beat Maker can generate entire patterns for you as a starting point. You can then edit and tweak the beat to your liking. Great for solving the "blank canvas" problem and giving you something good to start from.
* Advanced export options. This is where it really shines for producers. You can export your work as:
* A standard WAV loop
* Individual stems (ZIP)
* A MIDI file
* A ZIP file of all your samples as WAVs
* A SoundFont (.sf2) drum kit from your generated samples
* An Impulse Tracker (.it) file for use in trackers like Renoise, OpenMPT or a Polyend
* Pocket Operator/Volca sync. It can output a sync signal on the left audio channel to sync with these hardware devices for perfect timing.
* Per-Note FX. You can add effects like volume slides, repeats, and start volume changes to individual notes for more complex drum phrases incorporating flam and roll.<p>As an old school tracker guy, I'm particularly excited about the Impulse Tracker export mode. I was surprised to discover how many DAWs (including hardware like Polyend) can import this format. Of course, you can also pull up Impulse Tracker on DOSBox, or the more modern re-implementation, Schismtracker for that retro experience.<p>By the way, the beat generator feature is not trained on any artists or anything like that. It's an algorithm I built from scratch myself.<p>The audio engine is built on a declarative audio graph (using `virtual-audio-graph`), inspired by React's virtual DOM, which makes managing the Web Audio API much cleaner. If you're building web based audio apps I highly recommend checking out this library.<p>I'd love for you to try it out and let me know what you think. Feedback (and the inevitable bug reports) most welcome! Thank you!<p>P.S. Also, here's a video summary: <a href="https://youtu.be/qVmEn9z3H24" rel="nofollow">https://youtu.be/qVmEn9z3H24</a>
Show HN: I made a generative online drum machine with ClojureScript
After two years of development, I'm super excited to release Beat Maker! This is my take on what I hope is the best free, web-based drum machine.<p>My goal was to build something that was not only fun and easy to use for beginners but also powerful enough for serious producers. I did extensive research on existing drum machines, analyzed their UX, and tried to build something that adds something new.<p>It's a nearly 100% client-side app, written in ClojureScript, and is a PWA so you can install it to your home screen for an app-like experience.<p>Besides the standard grid editor, Beat Maker has some unique features that I think HN readers might find interesting:<p>- Procedural sample generation. One annoying thing about writing beats is searching through folders full of samples. I wanted to improve this and so I added the ability to generate new samples with a single click, giving you an infinite supply of unique drum samples.
* Generative beat creation. If you're looking for inspiration, Beat Maker can generate entire patterns for you as a starting point. You can then edit and tweak the beat to your liking. Great for solving the "blank canvas" problem and giving you something good to start from.
* Advanced export options. This is where it really shines for producers. You can export your work as:
* A standard WAV loop
* Individual stems (ZIP)
* A MIDI file
* A ZIP file of all your samples as WAVs
* A SoundFont (.sf2) drum kit from your generated samples
* An Impulse Tracker (.it) file for use in trackers like Renoise, OpenMPT or a Polyend
* Pocket Operator/Volca sync. It can output a sync signal on the left audio channel to sync with these hardware devices for perfect timing.
* Per-Note FX. You can add effects like volume slides, repeats, and start volume changes to individual notes for more complex drum phrases incorporating flam and roll.<p>As an old school tracker guy, I'm particularly excited about the Impulse Tracker export mode. I was surprised to discover how many DAWs (including hardware like Polyend) can import this format. Of course, you can also pull up Impulse Tracker on DOSBox, or the more modern re-implementation, Schismtracker for that retro experience.<p>By the way, the beat generator feature is not trained on any artists or anything like that. It's an algorithm I built from scratch myself.<p>The audio engine is built on a declarative audio graph (using `virtual-audio-graph`), inspired by React's virtual DOM, which makes managing the Web Audio API much cleaner. If you're building web based audio apps I highly recommend checking out this library.<p>I'd love for you to try it out and let me know what you think. Feedback (and the inevitable bug reports) most welcome! Thank you!<p>P.S. Also, here's a video summary: <a href="https://youtu.be/qVmEn9z3H24" rel="nofollow">https://youtu.be/qVmEn9z3H24</a>
Show HN: I made a generative online drum machine with ClojureScript
After two years of development, I'm super excited to release Beat Maker! This is my take on what I hope is the best free, web-based drum machine.<p>My goal was to build something that was not only fun and easy to use for beginners but also powerful enough for serious producers. I did extensive research on existing drum machines, analyzed their UX, and tried to build something that adds something new.<p>It's a nearly 100% client-side app, written in ClojureScript, and is a PWA so you can install it to your home screen for an app-like experience.<p>Besides the standard grid editor, Beat Maker has some unique features that I think HN readers might find interesting:<p>- Procedural sample generation. One annoying thing about writing beats is searching through folders full of samples. I wanted to improve this and so I added the ability to generate new samples with a single click, giving you an infinite supply of unique drum samples.
* Generative beat creation. If you're looking for inspiration, Beat Maker can generate entire patterns for you as a starting point. You can then edit and tweak the beat to your liking. Great for solving the "blank canvas" problem and giving you something good to start from.
* Advanced export options. This is where it really shines for producers. You can export your work as:
* A standard WAV loop
* Individual stems (ZIP)
* A MIDI file
* A ZIP file of all your samples as WAVs
* A SoundFont (.sf2) drum kit from your generated samples
* An Impulse Tracker (.it) file for use in trackers like Renoise, OpenMPT or a Polyend
* Pocket Operator/Volca sync. It can output a sync signal on the left audio channel to sync with these hardware devices for perfect timing.
* Per-Note FX. You can add effects like volume slides, repeats, and start volume changes to individual notes for more complex drum phrases incorporating flam and roll.<p>As an old school tracker guy, I'm particularly excited about the Impulse Tracker export mode. I was surprised to discover how many DAWs (including hardware like Polyend) can import this format. Of course, you can also pull up Impulse Tracker on DOSBox, or the more modern re-implementation, Schismtracker for that retro experience.<p>By the way, the beat generator feature is not trained on any artists or anything like that. It's an algorithm I built from scratch myself.<p>The audio engine is built on a declarative audio graph (using `virtual-audio-graph`), inspired by React's virtual DOM, which makes managing the Web Audio API much cleaner. If you're building web based audio apps I highly recommend checking out this library.<p>I'd love for you to try it out and let me know what you think. Feedback (and the inevitable bug reports) most welcome! Thank you!<p>P.S. Also, here's a video summary: <a href="https://youtu.be/qVmEn9z3H24" rel="nofollow">https://youtu.be/qVmEn9z3H24</a>
Show HN: I made a generative online drum machine with ClojureScript
After two years of development, I'm super excited to release Beat Maker! This is my take on what I hope is the best free, web-based drum machine.<p>My goal was to build something that was not only fun and easy to use for beginners but also powerful enough for serious producers. I did extensive research on existing drum machines, analyzed their UX, and tried to build something that adds something new.<p>It's a nearly 100% client-side app, written in ClojureScript, and is a PWA so you can install it to your home screen for an app-like experience.<p>Besides the standard grid editor, Beat Maker has some unique features that I think HN readers might find interesting:<p>- Procedural sample generation. One annoying thing about writing beats is searching through folders full of samples. I wanted to improve this and so I added the ability to generate new samples with a single click, giving you an infinite supply of unique drum samples.
* Generative beat creation. If you're looking for inspiration, Beat Maker can generate entire patterns for you as a starting point. You can then edit and tweak the beat to your liking. Great for solving the "blank canvas" problem and giving you something good to start from.
* Advanced export options. This is where it really shines for producers. You can export your work as:
* A standard WAV loop
* Individual stems (ZIP)
* A MIDI file
* A ZIP file of all your samples as WAVs
* A SoundFont (.sf2) drum kit from your generated samples
* An Impulse Tracker (.it) file for use in trackers like Renoise, OpenMPT or a Polyend
* Pocket Operator/Volca sync. It can output a sync signal on the left audio channel to sync with these hardware devices for perfect timing.
* Per-Note FX. You can add effects like volume slides, repeats, and start volume changes to individual notes for more complex drum phrases incorporating flam and roll.<p>As an old school tracker guy, I'm particularly excited about the Impulse Tracker export mode. I was surprised to discover how many DAWs (including hardware like Polyend) can import this format. Of course, you can also pull up Impulse Tracker on DOSBox, or the more modern re-implementation, Schismtracker for that retro experience.<p>By the way, the beat generator feature is not trained on any artists or anything like that. It's an algorithm I built from scratch myself.<p>The audio engine is built on a declarative audio graph (using `virtual-audio-graph`), inspired by React's virtual DOM, which makes managing the Web Audio API much cleaner. If you're building web based audio apps I highly recommend checking out this library.<p>I'd love for you to try it out and let me know what you think. Feedback (and the inevitable bug reports) most welcome! Thank you!<p>P.S. Also, here's a video summary: <a href="https://youtu.be/qVmEn9z3H24" rel="nofollow">https://youtu.be/qVmEn9z3H24</a>
Show HN: Making a cross-platform game in Go using WebRTC Datachannels
Show HN: Making a cross-platform game in Go using WebRTC Datachannels
Show HN: Robot MCP Server – Connect Any Language Model and ROS Robots Using MCP
We’ve open-sourced the Robot MCP Server, a tool that lets large language models (LLMs) talk directly to robots running ROS1 or ROS2.<p>What it does
- Connects any LLM to existing ROS robots via the Model Context Protocol (MCP)
- Natural language → ROS topics, services, and actions (And the ability to read any of them back)
- Works without changing robot source code<p>Why it matters
- Makes robots accessible from natural language interfaces
- Opens the door to rapid prototyping of AI-robot applications
- We are trying to create a common interface for safe AI ↔ robot communication<p>This is too big to develop alone — we’d love feedback, contributors, and partners from both the robotics and AI communities.
Show HN: CrabCamera – Cross-platform camera plugin for Tauri desktop apps
After building several Tauri desktop apps, I kept hitting the same wall: there's no reliable way to access cameras across Windows, macOS, and Linux. Every project meant reinventing camera integration,
dealing with platform-specific APIs, and debugging permission issues.<p><pre><code> So I built CrabCamera – a Tauri plugin that handles all the camera complexity for you.
What it does:
- One API, three platforms: Same Rust code works on Windows (DirectShow), macOS (AVFoundation), and Linux (V4L2)
- Permission handling: Automatically requests camera permissions on each platform
- Format conversion: Takes care of the messy bits between platform formats and what your app needs
- Error handling: Proper Rust error types instead of mysterious crashes
- Hot-plugging: Detects when cameras are connected/disconnected
The problem it solves:
Before CrabCamera, adding camera support to a Tauri app meant:
1. Writing separate native code for each platform
2. Managing three different permission systems
3. Handling format conversions manually
4. Debugging platform-specific edge cases
5. Maintaining it all as OS APIs change
Now it's just:
use crabcamera::Camera;
let camera = Camera::new()?;
let frame = camera.capture_frame().await?;
Why I built it:
I was working on a plant monitoring app (botanica) that needed reliable camera access for time-lapse photography. Existing solutions were either abandoned, platform-specific, or required complex native
bindings.
The Tauri ecosystem is growing fast, but camera support was this obvious gap. Every desktop app eventually needs camera access – video calls, document scanning, AR features, security monitoring.
Technical highlights:
- Uses nokhwa for the heavy lifting but wraps it in Tauri-friendly APIs
- Proper async/await support throughout
- Memory-efficient streaming for video capture
- Built-in image processing pipeline
- Extensible plugin architecture
What's next:
- WebRTC integration for video calls
- Built-in barcode/QR code scanning
- Face detection hooks
- Performance optimizations for 4K streams
The crate is MIT licensed and available on crates.io. I'd love feedback from other Tauri developers who've wrestled with camera integration.
Links:
- Crates.io: https://crates.io/crates/crabcamera
- GitHub: https://github.com/Michael-A-Kuykendall/crabcamera
- Documentation: https://docs.rs/crabcamera</code></pre>