News updates

Show HN: Sirenfall, a civil defense siren synthesized in Web Audio I built a cool browser scene, a shelter window over a dystopian city in the rain. Pull the breaker and a siren tower spins up. The wind-down is super unsettling and I love it. The siren is not a recording. Two port rings make a 5:6 dual tone, 515 and 618 Hz. The horn turns at 4 RPM and everything (loudness, brightness, doppler and stereo position) follows the horn angle you can see on the tower. Rain and thunder are the only recordings. Build it yourself, source is one HTML file and MIT: https://ift.tt/LtPaAfh How it works: https://sirenfall.live/how-it-works Press F for fullscreen, S to save a picture. Landscape on phones. No cookies, no personal data, the only request besides audio is an anonymous page-count pixel. Appreciate any feedback and shoutout to the siren community! https://sirenfall.live/ September 4, 2026 at 02:14AM

Show HN: Bridle: hand your agent's context to a coworker's agent A college went on holiday this week and his agent was the one that did the whole migration from Shopware to Shopify. All products, domains, DNS- basically, it had all the knowledge. I spent the morning figuring out how to answer questions to client and finish up what was left to do. From then on we connected our agents with Bridle. Bridle is a CLI that moves work between agents, so that handoff is a command rather than a memory: bridle send marko.dev --note "migration 0042 is half-applied, continue" bridle queue marko.dev --title "finish the retry backoff — see the note" bridle inbox Idea came from Tailscale where both ends need to connect in (bridle up). Being on the same mesh grants nothing on its own. Alos payloads are sealed to the recipient, so the coordination server routes by name and holds ciphertext it can't read. I tried to make it super simple to run and free to test: npm i...

Show HN: NGPDFs – 50 PDF tools that never upload your files https://ngpdfs.com September 3, 2026 at 11:13PM

Show HN: Arbitale – emergent choose your own adventure game Hi everyone! I am building Arbitale and it is currently in pre-alpha. I'm looking for play-testers who can give feedback on the product. The goal is to eventually have different characters in the game be their own agents, with emergent narratives that are totally unique to each playthrough. Each agent acts according to its own pre-written incentives. Would love to hear what you think! https://ift.tt/bc0Kx2L September 3, 2026 at 12:12AM

Show HN: Codeknow – Architecture health scores for any codebase, no LLM needed https://ift.tt/movDMnI September 2, 2026 at 11:51PM

Show HN: SufferTrails, the Anti-AllTrails Don't get me wrong. I love a good family-friendly hike as much as anyone else. But sometimes you want to be grimacing, not smiling, on the trail. SufferTrails is that, and not much else. All trails not allowed. https://ift.tt/QKMehPy September 2, 2026 at 11:27PM

Show HN: AQ – A multiplayer workspace for coding agents on your own cloud https://aq.dev/ September 2, 2026 at 11:16PM

Show HN: Newton's Orchard – Browser-based space/gravity playground Hi HN! My son spent a lot of time in 5th grade playing with the 2-dimensional PhET gravity/space sims[1]. His STEM class uses it, and he was playing with it at home, and has been looking for more. I found several space sims/playgrounds online, including NASA's Eyes on the Solar System[2], but nothing that seemed to offer a real progression from what he was getting out of the PhET sims, so I built Newton's Orchard over the summer for him. https://ift.tt/hw8neyE The source is also published at https://ift.tt/i0ZMlAt It features deterministic time scrubbing, all bodies are editable, different preset systems and experiments, missions to complete (complete 3 to unlock the blackhole object type and mission), and a gallery for user submissions. I would very much appreciate feedback from HN - particularly from the lens of making it engaging and illuminating for students, and anyone that would like to just get a ...

Show HN: Mcptunnels – ngrok for MCP with basic OAuth Basically, OpenAI tunneling sucks and is broken most of the time. This can get you tunneling pretty trivially to share with someone temporarily. Roadmap includes being able to host MCP servers trivially as well. https://terragohan.github.io/mcptunnels/ September 2, 2026 at 02:04AM

Show HN: Semantic Overlays – an NX bit for LLM prompt injection (live demo) I've built a new method for steering LLMs called Semantic Overlays, small trained adapters on a frozen model which change how it perceives a piece of its context. The most readily applicable usage is to mitigate prompt injection, and it lets us take a very-injectable Qwen-3.5-9B to SOTA scores on all the prompt injection benchmarks I could find. (They are only blackbox attacks, but I did NOT train on anything like them — whitebox attacks are out of scope for this paper) I'm excited for you to play with the tech — see if YOU can break it! (let me know if you can) Paper at https://ift.tt/Bz9MjUc if you want to read more about it, code at https://ift.tt/vZJVY8r , adapters at https://ift.tt/Rkdxl8o... Also https://ift.tt/pxdSq3P if you wanna watch a little video I made! https://semantic-overlays.vercel.app/ September 1, 2026 at 11:10PM