The best Hacker News stories from Show from the past day
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Show HN: A modern C++20 AI SDK (GPT‑4o, Claude 3.5, tool‑calling)
Hi all,<p>I’m hacking on new features for the ClickHouse native client and wanted the same “just call the model” ergonomics JavaScript and Python now enjoy. It didn’t exist for modern C++, so I wrote one.<p>ai‑sdk‑cpp (Apache‑2.0) gives you:<p>- Unified calls to OpenAI (GPT‑4o) and Anthropic (Claude 3.5) with a single C++20 API.
- Streaming, multi‑turn chat, error handling—all std::optional/std::variant, no macros.
- Tool calling (function‑calling) so the model can hit real APIs; sync or async, runs in parallel.<p>The tricky bit: C++ still lacks real reflection, so mapping plain functions → JSON schemas isn’t as automatic as, say, TypeScript decorators. I’d love fresh eyes on that part. Try the examples and tell me where it feels clunky. This is inspired by Vercel's AI SDK [1], and litellm [2].<p>Repo live here: <a href="https://github.com/ClickHouse/ai-sdk-cpp">https://github.com/ClickHouse/ai-sdk-cpp</a>, feedback welcome!<p>[1] <a href="https://github.com/vercel/ai">https://github.com/vercel/ai</a>
[2] <a href="https://github.com/BerriAI/litellm">https://github.com/BerriAI/litellm</a>
Show HN: Arch-Router – 1.5B model for LLM routing by preferences, not benchmarks
Hi HN — we're the team behind Arch (<a href="https://github.com/katanemo/archgw">https://github.com/katanemo/archgw</a>), an open-source proxy for LLMs written in Rust. Today we're releasing Arch-Router (<a href="https://huggingface.co/katanemo/Arch-Router-1.5B" rel="nofollow">https://huggingface.co/katanemo/Arch-Router-1.5B</a>), a 1.5B router model for preference-based routing, now integrated into the proxy. As teams integrate multiple LLMs - each with different strengths, styles, or cost/latency profiles — routing the right prompt to the right model becomes a critical part of the application design. But it's still an open problem. Most routing systems fall into two camps:<p>- Embedding-based routers use intent classifiers — label a prompt as “support,” “SQL,” or “math,” then route to a matching model. This works for simple tasks but breaks down in real conversations. Users shift topics mid-conversation, task boundaries blur, and product changes require retraining classifiers.<p>- Performance-based routers pick models based on benchmarks like MMLU or MT-Bench, or based on latency or cost curves. But benchmarks often miss what matters in production: domain-specific quality or subjective preferences like “Will legal accept this clause?”<p>Arch-Router takes a different approach: route by preferences written in plain language. You write rules like “contract clauses → GPT-4o” or “quick travel tips → Gemini Flash.” The router maps the prompt (and conversation context) to those rules using a lightweight 1.5B autoregressive model. No retraining, no fragile if/else chains. We built this with input from teams at Twilio and Atlassian. It handles intent drift, supports multi-turn conversations, and lets you swap in or out models with a one-line change to the routing policy. Full details are in our paper (<a href="https://arxiv.org/abs/2506.16655" rel="nofollow">https://arxiv.org/abs/2506.16655</a>), but here's a snapshot:<p>Specs:<p>- 1.5B params — runs on a single GPU (or CPU for testing)<p>- No retraining needed — point it at any mix of LLMs<p>- Cost and latency aware — route heavy tasks to expensive models, light tasks to faster/cheaper ones<p>- Outperforms larger closed models on our conversational routing benchmarks (details in the paper)<p>Links:<p>- Arch Proxy (open source): <a href="https://github.com/katanemo/archgw">https://github.com/katanemo/archgw</a><p>- Model + code: <a href="https://huggingface.co/katanemo/Arch-Router-1.5B" rel="nofollow">https://huggingface.co/katanemo/Arch-Router-1.5B</a><p>- Paper: <a href="https://arxiv.org/abs/2506.16655" rel="nofollow">https://arxiv.org/abs/2506.16655</a>
Show HN: I made a 2D game engine in Dart
Show HN: I made a 2D game engine in Dart
Show HN: CSS generator for a high-def glass effect
There are lots of glassmorphism generators out there, but I wanted to push the effect further! This project is the result of months of experimenting with CSS property layering and battling browser quirks.<p>Cross-browser compatibility is actually the reason I rely on ::before and ::after pseudo-elements to build up the effect. Move the color/opacity to the main element, and you’ll get weird color bleed on the corners in Chrome. Move the texture, and it muddles the bevel’s specular highlight. Move the bevel, and it gets blurred out by the backdrop-filter. And so on!<p>Layers include:
* Adjustable blur, brightness, and saturation (backdrop-filter)
* Subtle translucent texture
* Faux 3D bevel (using box-shadows, not an outline)<p>Glassmorphism is rather heavy on resources, so it’s best used as an accent and avoided on wide desktop elements.
Should be compatible with recent versions of Chrome, Safari, and Firefox (desktop and mobile). If you spot bugs or rendering glitches, I’d love to know!<p>Side note: this is an early preview of a framework-agnostic glass SCSS/component library I’m building.
Show HN: CSS generator for a high-def glass effect
There are lots of glassmorphism generators out there, but I wanted to push the effect further! This project is the result of months of experimenting with CSS property layering and battling browser quirks.<p>Cross-browser compatibility is actually the reason I rely on ::before and ::after pseudo-elements to build up the effect. Move the color/opacity to the main element, and you’ll get weird color bleed on the corners in Chrome. Move the texture, and it muddles the bevel’s specular highlight. Move the bevel, and it gets blurred out by the backdrop-filter. And so on!<p>Layers include:
* Adjustable blur, brightness, and saturation (backdrop-filter)
* Subtle translucent texture
* Faux 3D bevel (using box-shadows, not an outline)<p>Glassmorphism is rather heavy on resources, so it’s best used as an accent and avoided on wide desktop elements.
Should be compatible with recent versions of Chrome, Safari, and Firefox (desktop and mobile). If you spot bugs or rendering glitches, I’d love to know!<p>Side note: this is an early preview of a framework-agnostic glass SCSS/component library I’m building.
Show HN: CSS generator for a high-def glass effect
There are lots of glassmorphism generators out there, but I wanted to push the effect further! This project is the result of months of experimenting with CSS property layering and battling browser quirks.<p>Cross-browser compatibility is actually the reason I rely on ::before and ::after pseudo-elements to build up the effect. Move the color/opacity to the main element, and you’ll get weird color bleed on the corners in Chrome. Move the texture, and it muddles the bevel’s specular highlight. Move the bevel, and it gets blurred out by the backdrop-filter. And so on!<p>Layers include:
* Adjustable blur, brightness, and saturation (backdrop-filter)
* Subtle translucent texture
* Faux 3D bevel (using box-shadows, not an outline)<p>Glassmorphism is rather heavy on resources, so it’s best used as an accent and avoided on wide desktop elements.
Should be compatible with recent versions of Chrome, Safari, and Firefox (desktop and mobile). If you spot bugs or rendering glitches, I’d love to know!<p>Side note: this is an early preview of a framework-agnostic glass SCSS/component library I’m building.
Show HN: HackerNewt – Breadth-first exploring HN client for iOS
I made a HN client that allows you to explore comments in a breadth-first manner. Compared to the classic depth-first approach, it works much better for the larger threads - you don't lose the context and can easily skip discussions you're not interested in.<p>Video preview: <a href="https://imgur.com/a/tzBdpXw" rel="nofollow">https://imgur.com/a/tzBdpXw</a>
Show HN: HackerNewt – Breadth-first exploring HN client for iOS
I made a HN client that allows you to explore comments in a breadth-first manner. Compared to the classic depth-first approach, it works much better for the larger threads - you don't lose the context and can easily skip discussions you're not interested in.<p>Video preview: <a href="https://imgur.com/a/tzBdpXw" rel="nofollow">https://imgur.com/a/tzBdpXw</a>
Show HN: Core – open source memory graph for LLMs – shareable, user owned
I keep running in the same problem of each AI app “remembers” me in its own silo. ChatGPT knows my project details, Cursor forgets them, Claude starts from zero… so I end up re-explaining myself dozens of times a day across these apps.<p>The deeper problem<p>1. Not portable – context is vendor-locked; nothing travels across tools.<p>2. Not relational – most memory systems store only the latest fact (“sticky notes”) with no history or provenance.<p>3. Not yours – your AI memory is sensitive first-party data, yet you have no control over where it lives or how it’s queried.<p>Demo video: <a href="https://youtu.be/iANZ32dnK60" rel="nofollow">https://youtu.be/iANZ32dnK60</a><p>Repo: <a href="https://github.com/RedPlanetHQ/core">https://github.com/RedPlanetHQ/core</a><p>What we built<p>- CORE (Context Oriented Relational Engine): An open source, shareable knowledge graph (your memory vault) that lets any LLM (ChatGPT, Cursor, Claude, SOL, etc.) share and query the same persistent context.<p>- Temporal + relational: Every fact gets a full version history (who, when, why), and nothing is wiped out when you change it—just timestamped and retired.<p>- Local-first or hosted: Run it offline in Docker, or use our hosted instance. You choose which memories sync and which stay private.<p>Try it<p>- Hosted free tier (HN launch): <a href="https://core.heysol.ai">https://core.heysol.ai</a><p>- Docs: <a href="https://docs.heysol.ai/core/overview">https://docs.heysol.ai/core/overview</a>
Show HN: Core – open source memory graph for LLMs – shareable, user owned
I keep running in the same problem of each AI app “remembers” me in its own silo. ChatGPT knows my project details, Cursor forgets them, Claude starts from zero… so I end up re-explaining myself dozens of times a day across these apps.<p>The deeper problem<p>1. Not portable – context is vendor-locked; nothing travels across tools.<p>2. Not relational – most memory systems store only the latest fact (“sticky notes”) with no history or provenance.<p>3. Not yours – your AI memory is sensitive first-party data, yet you have no control over where it lives or how it’s queried.<p>Demo video: <a href="https://youtu.be/iANZ32dnK60" rel="nofollow">https://youtu.be/iANZ32dnK60</a><p>Repo: <a href="https://github.com/RedPlanetHQ/core">https://github.com/RedPlanetHQ/core</a><p>What we built<p>- CORE (Context Oriented Relational Engine): An open source, shareable knowledge graph (your memory vault) that lets any LLM (ChatGPT, Cursor, Claude, SOL, etc.) share and query the same persistent context.<p>- Temporal + relational: Every fact gets a full version history (who, when, why), and nothing is wiped out when you change it—just timestamped and retired.<p>- Local-first or hosted: Run it offline in Docker, or use our hosted instance. You choose which memories sync and which stay private.<p>Try it<p>- Hosted free tier (HN launch): <a href="https://core.heysol.ai">https://core.heysol.ai</a><p>- Docs: <a href="https://docs.heysol.ai/core/overview">https://docs.heysol.ai/core/overview</a>
Show HN: Core – open source memory graph for LLMs – shareable, user owned
I keep running in the same problem of each AI app “remembers” me in its own silo. ChatGPT knows my project details, Cursor forgets them, Claude starts from zero… so I end up re-explaining myself dozens of times a day across these apps.<p>The deeper problem<p>1. Not portable – context is vendor-locked; nothing travels across tools.<p>2. Not relational – most memory systems store only the latest fact (“sticky notes”) with no history or provenance.<p>3. Not yours – your AI memory is sensitive first-party data, yet you have no control over where it lives or how it’s queried.<p>Demo video: <a href="https://youtu.be/iANZ32dnK60" rel="nofollow">https://youtu.be/iANZ32dnK60</a><p>Repo: <a href="https://github.com/RedPlanetHQ/core">https://github.com/RedPlanetHQ/core</a><p>What we built<p>- CORE (Context Oriented Relational Engine): An open source, shareable knowledge graph (your memory vault) that lets any LLM (ChatGPT, Cursor, Claude, SOL, etc.) share and query the same persistent context.<p>- Temporal + relational: Every fact gets a full version history (who, when, why), and nothing is wiped out when you change it—just timestamped and retired.<p>- Local-first or hosted: Run it offline in Docker, or use our hosted instance. You choose which memories sync and which stay private.<p>Try it<p>- Hosted free tier (HN launch): <a href="https://core.heysol.ai">https://core.heysol.ai</a><p>- Docs: <a href="https://docs.heysol.ai/core/overview">https://docs.heysol.ai/core/overview</a>
Show HN: I built the tool I wished existed for moving Stripe between countries
In late 2024, I had to set up a new Stripe account because I incorporated my company in a different country. Turns out it's not as simple as just changing the country in a dropdown, you have to start from scratch.<p>I had hundreds of users and using Stripe's dashboard to add all of the products, prices, coupons and subscriptions manually would take ages. I contacted a couple of services that help with this kind of migration, but their quotes were way over my budget. My next option was to use Stripe's API, which is very powerful but also very complicated. I'm a designer who can code, but I didn't feel confident doing it alone, so I asked a friend, an experienced developer, to help.<p>It proved to be quite challenging, with many details and caveats we had to learn as we went. What we thought would take a couple of days took us a week.<p>After this experience, we teamed up and built <a href="https://stripemove.com" rel="nofollow">https://stripemove.com</a>, a tool that guides you through this whole process, explaining and automating that hard week we went through. It handles the technical complexity while keeping your business running. Customers keep paying on your old account while everything transfers in parallel, then you flip the switch when ready.<p>It's a very niche tool, built for founders who need to change their company location for personal or business reasons. For entrepreneurs buying companies established in other countries. For people in the same situation I was in a few months ago. Basically the tool I wished existed, and for a fair price. Designed to get you through this inconvenient process and back as soon as possible on growing your business.<p>Would love to hear from anyone who's dealt with similar Stripe migrations. What was your biggest pain point?
Show HN: I built the tool I wished existed for moving Stripe between countries
In late 2024, I had to set up a new Stripe account because I incorporated my company in a different country. Turns out it's not as simple as just changing the country in a dropdown, you have to start from scratch.<p>I had hundreds of users and using Stripe's dashboard to add all of the products, prices, coupons and subscriptions manually would take ages. I contacted a couple of services that help with this kind of migration, but their quotes were way over my budget. My next option was to use Stripe's API, which is very powerful but also very complicated. I'm a designer who can code, but I didn't feel confident doing it alone, so I asked a friend, an experienced developer, to help.<p>It proved to be quite challenging, with many details and caveats we had to learn as we went. What we thought would take a couple of days took us a week.<p>After this experience, we teamed up and built <a href="https://stripemove.com" rel="nofollow">https://stripemove.com</a>, a tool that guides you through this whole process, explaining and automating that hard week we went through. It handles the technical complexity while keeping your business running. Customers keep paying on your old account while everything transfers in parallel, then you flip the switch when ready.<p>It's a very niche tool, built for founders who need to change their company location for personal or business reasons. For entrepreneurs buying companies established in other countries. For people in the same situation I was in a few months ago. Basically the tool I wished existed, and for a fair price. Designed to get you through this inconvenient process and back as soon as possible on growing your business.<p>Would love to hear from anyone who's dealt with similar Stripe migrations. What was your biggest pain point?
Show HN: I built the tool I wished existed for moving Stripe between countries
In late 2024, I had to set up a new Stripe account because I incorporated my company in a different country. Turns out it's not as simple as just changing the country in a dropdown, you have to start from scratch.<p>I had hundreds of users and using Stripe's dashboard to add all of the products, prices, coupons and subscriptions manually would take ages. I contacted a couple of services that help with this kind of migration, but their quotes were way over my budget. My next option was to use Stripe's API, which is very powerful but also very complicated. I'm a designer who can code, but I didn't feel confident doing it alone, so I asked a friend, an experienced developer, to help.<p>It proved to be quite challenging, with many details and caveats we had to learn as we went. What we thought would take a couple of days took us a week.<p>After this experience, we teamed up and built <a href="https://stripemove.com" rel="nofollow">https://stripemove.com</a>, a tool that guides you through this whole process, explaining and automating that hard week we went through. It handles the technical complexity while keeping your business running. Customers keep paying on your old account while everything transfers in parallel, then you flip the switch when ready.<p>It's a very niche tool, built for founders who need to change their company location for personal or business reasons. For entrepreneurs buying companies established in other countries. For people in the same situation I was in a few months ago. Basically the tool I wished existed, and for a fair price. Designed to get you through this inconvenient process and back as soon as possible on growing your business.<p>Would love to hear from anyone who's dealt with similar Stripe migrations. What was your biggest pain point?
Show HN: Jobs by Referral: Find jobs in your LinkedIn network
I have some friends who were laid off and are on the job hunt. We were all quite surprised to learn that LinkedIn does not have a "view jobs only at companies where I have connections", so I built <a href="https://jobsbyreferral.com/" rel="nofollow">https://jobsbyreferral.com/</a><p>It's powered by <a href="https://rapidapi.com/letscrape-6bRBa3QguO5/api/jsearch" rel="nofollow">https://rapidapi.com/letscrape-6bRBa3QguO5/api/jsearch</a>, which is a little pricey, so I'm trying to decide whether to put more effort into the project (I'd have to charge _something_ to offset the costs).
Show HN: Jobs by Referral: Find jobs in your LinkedIn network
I have some friends who were laid off and are on the job hunt. We were all quite surprised to learn that LinkedIn does not have a "view jobs only at companies where I have connections", so I built <a href="https://jobsbyreferral.com/" rel="nofollow">https://jobsbyreferral.com/</a><p>It's powered by <a href="https://rapidapi.com/letscrape-6bRBa3QguO5/api/jsearch" rel="nofollow">https://rapidapi.com/letscrape-6bRBa3QguO5/api/jsearch</a>, which is a little pricey, so I'm trying to decide whether to put more effort into the project (I'd have to charge _something_ to offset the costs).
Show HN: Jobs by Referral: Find jobs in your LinkedIn network
I have some friends who were laid off and are on the job hunt. We were all quite surprised to learn that LinkedIn does not have a "view jobs only at companies where I have connections", so I built <a href="https://jobsbyreferral.com/" rel="nofollow">https://jobsbyreferral.com/</a><p>It's powered by <a href="https://rapidapi.com/letscrape-6bRBa3QguO5/api/jsearch" rel="nofollow">https://rapidapi.com/letscrape-6bRBa3QguO5/api/jsearch</a>, which is a little pricey, so I'm trying to decide whether to put more effort into the project (I'd have to charge _something_ to offset the costs).
Show HN: Jobs by Referral: Find jobs in your LinkedIn network
I have some friends who were laid off and are on the job hunt. We were all quite surprised to learn that LinkedIn does not have a "view jobs only at companies where I have connections", so I built <a href="https://jobsbyreferral.com/" rel="nofollow">https://jobsbyreferral.com/</a><p>It's powered by <a href="https://rapidapi.com/letscrape-6bRBa3QguO5/api/jsearch" rel="nofollow">https://rapidapi.com/letscrape-6bRBa3QguO5/api/jsearch</a>, which is a little pricey, so I'm trying to decide whether to put more effort into the project (I'd have to charge _something_ to offset the costs).
Show HN: Spegel, a Terminal Browser That Uses LLMs to Rewrite Webpages