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[Other] Show HN: I reverse engineered macOS to allow custom Lock Screen wallpapers Hi HN, I&#x27;m Oskar, a solo indie Mac developer from Sweden. For those in the Mac community, you might know me from my other apps like Sensei and Trim Enabler.<p>For years, I&#x27;ve been frustrated by the lack of customisation of macOS. In particular the Lock Screen which supports animated wallpapers, but only ones provided by Apple. There&#x27;s never been a way to add your own personal videos.<p>I decided to figure out how to solve this, and the result is Backdrop 2.0. Backdrop is my Live Wallpaper app for Mac, it can play video wallpapers on your desktop. And now it can play on your Lock Screen too.<p>The core technical challenge, as you can imagine, came from trying to do something that Apple otherwise does not allow. However, through extensive reverse engineering of the macOS wallpaper system, I figured out a way to provide Backdrop wallpapers to the system in a way that allows them to play on the lock screen, and even appear in a custom section in System Settings.<p>I&#x27;m here all day to answer any questions—especially about the reverse engineering process, the challenges of integrating with macOS, or the experience of being an indie Mac developer.<p>Would love to hear your thoughts and feedback.

[Other] For Good First Issue – A repository of social impact and open source projects

[Other] Show HN: Dagger.js – A buildless, runtime-only JavaScript micro-framework TL;DR: dagger.js is a buildless, runtime-only micro-framework that plays nicely with native Web Components. It uses HTML-first directives (e.g. +click, +load) so you can ship a page by dropping a single &lt;script&gt; from a CDN—no bundlers, no compile step.<p>Why I built it Modern stacks are powerful but often heavy: bundlers, compile steps, framework DSLs, local CLIs. For internal tools, small apps, and edge&#x2F;serverless deployments, I wanted something you can view-source, paste into a page, and ship.<p>What it is:<p>Runtime-only: no build or VDOM compile; hydrate behaviors directly on HTML. HTML directives: e.g. +click, lifecycle +load &#x2F; +loaded &#x2F; +unload &#x2F; +unloaded. Zero APIs: dagger.js works in pure declarative mode, modules and directives provide everything you need to build your application. Web-Components-first: works alongside Custom Elements; keep concerns local. Distributed modules: load small, focused script modules via CDN. Progressive enhancement: the page renders without a build step.<p>Use cases:<p>Admin panels &amp; dashboards that don’t warrant a full toolchain Embed widgets, docs-sites with interactive bits Edge&#x2F;serverless apps where cold start and simplicity matter<p>Links<p>GitHub: <a href="https:&#x2F;&#x2F;github.com&#x2F;dagger8224&#x2F;dagger.js" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;dagger8224&#x2F;dagger.js</a> Docs&#x2F;Guide: <a href="https:&#x2F;&#x2F;daggerjs.org" rel="nofollow">https:&#x2F;&#x2F;daggerjs.org</a> Examples: <a href="https:&#x2F;&#x2F;codepen.io&#x2F;dagger8224&#x2F;pens" rel="nofollow">https:&#x2F;&#x2F;codepen.io&#x2F;dagger8224&#x2F;pens</a><p>I’d love feedback on edge-cases, and where it breaks. Happy to answer tough questions here.

[Other] Show HN: AI-powered web service combining FastAPI, Pydantic-AI, and MCP servers Hey all! I recently gave a workshop talk at PyCon Greece 2025 about building production-ready agent systems.<p>To check the workshop, I put together a demo repo: (I will add the slides too soon in my blog: <a href="https:&#x2F;&#x2F;www.petrostechchronicles.com&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.petrostechchronicles.com&#x2F;</a>) <a href="https:&#x2F;&#x2F;github.com&#x2F;Aherontas&#x2F;Pycon_Greece_2025_Presentation_Agents" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;Aherontas&#x2F;Pycon_Greece_2025_Presentation_...</a><p>The idea was to show how multiple AI agents can collaborate using FastAPI + Pydantic-AI, with protocols like MCP (Model Context Protocol) and A2A (Agent-to-Agent) for safe communication and orchestration.<p>Features:<p>- Multiple agents running in containers<p>- MCP servers (Brave search, GitHub, filesystem, etc.) as tools<p>- A2A communication between services<p>- Minimal UI for experimentation for Tech Trend - repo analysis<p>I built this repo because most agent frameworks look great in isolated demos, but fall apart when you try to glue agents together into a real application. My goal was to help people experiment with these patterns and move closer to real-world use cases.<p>It’s not production-grade, but would love feedback, criticism, or war stories from anyone who’s tried building actual multi-agent systems. Big questions:<p>Do you think agent-to-agent protocols like MCP&#x2F;A2A will stick?<p>Or will the future be mostly single powerful LLMs with plugin stacks?<p>Thanks — excited to hear what the HN crowd thinks!

[Other] Show HN: Datadef.io – Canvas for data lineage and metadata management Hi HN, I’ve been working on <a href="https:&#x2F;&#x2F;datadef.io" rel="nofollow">https:&#x2F;&#x2F;datadef.io</a>, a tool to help data team (engineer, architect, project manager) make sense of their data universe.<p>The problem:<p>- Data models (dbt, SQL, warehouses) often grow into a tangled mess of tables, joins, and undocumented assumptions. - Lineage is either scattered across tools or missing entirely. - Documentation is usually an afterthought (and gets outdated fast).<p>Datadef.io aims to fix that by providing:<p>- Interactive canvas to map tables, relationships, and indicators. - Automatic lineage visualization to trace dependencies. - Metadata management: define table&#x2F;column-level details, ownership, and KPIs. - AI-generated documentation that stays in sync with your models. - Export&#x2F;share features so asset managers, analysts, and other teams don’t get lost in spreadsheets or PDFs.<p>It’s still early, and I’d love feedback from the HN community. In particular:<p>What’s missing for you in lineage&#x2F;metadata&#x2F;documentation tools?<p>How would you want to integrate a tool like this into your workflow (dbt, Databricks, Power BI, etc.)?<p>I’d really appreciate your thoughts, feature requests, and criticism.<p>Thanks!

[Other] How Container Filesystem Works: Building a Docker-Like Container from Scratch

[Other] Show HN: CLAVIER-36 (programming environment for generative music) CLAVIER-36 is a programming environment for generative music. Programs are laid out in a two-dimensional grid, and evolve over time according to a fixed set of rules. The system is much like a cellular automaton, in that most of the rules governing the evolution of the system are local.<p>C36 programs describe sequences of discrete events in time. The environment includes a primitive sampler, as a self-contained means of interpreting these events as sound. For full expressivity, though, the system is best used as a generator of data for interpretation by an external musical instrument, such as a synthesizer.<p>The project was very directly inspired by Orca (<a href="https:&#x2F;&#x2F;100r.co&#x2F;site&#x2F;orca.html" rel="nofollow">https:&#x2F;&#x2F;100r.co&#x2F;site&#x2F;orca.html</a>). It began as my own from-scratch implementation of Orca and diverged over time.<p>It&#x27;s written in C, and compiled to WASM for the browser.<p>See the following pages for more info:<p>about page: <a href="https:&#x2F;&#x2F;clavier36.com&#x2F;about" rel="nofollow">https:&#x2F;&#x2F;clavier36.com&#x2F;about</a><p>user manual: <a href="https:&#x2F;&#x2F;clavier36.com&#x2F;manual" rel="nofollow">https:&#x2F;&#x2F;clavier36.com&#x2F;manual</a><p>tutorial video: <a href="https:&#x2F;&#x2F;youtu.be&#x2F;rIpQmJVMjCA" rel="nofollow">https:&#x2F;&#x2F;youtu.be&#x2F;rIpQmJVMjCA</a>

[Code Quality] Show HN: wcwidth-o1 – Find Unicode text cell width in no time for JavaScript/TS I ported Markus Kuhn’s wcwidth to TypeScript and optimized it with bitset lookups for O(1) performance. It now covers the full Unicode 15.1 combining ranges.<p>GitHub: <a href="https:&#x2F;&#x2F;github.com&#x2F;dawsonhuang0&#x2F;Wcwidth-O1" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;dawsonhuang0&#x2F;Wcwidth-O1</a> NPM: <a href="https:&#x2F;&#x2F;www.npmjs.com&#x2F;package&#x2F;wcwidth-o1" rel="nofollow">https:&#x2F;&#x2F;www.npmjs.com&#x2F;package&#x2F;wcwidth-o1</a><p>Feedback welcome!

[Other] OCI Registry Explorer

[Database] Show HN: Tsink – Embedded time-series database for Rust

[Database] Vector database that can index 1B vectors in 48M

[Other] A Beginner's Guide to Extending Emacs

[Other] Show HN: DWS OS, a Plan 9 Inspired Web "OS" Hi HN,<p>I&#x27;ve always loved the aesthetic, quirks, and concepts of Plan9, and I wanted to see how far I could vibe-code a web desktop&#x2F;OS that resembled it. The result is DWS OS.<p>My goal was to reach a point where I could build &quot;userspace&quot; apps for this OS, in the OS. DWS OS has a virtual filesystem, an approximation of the ACME editor, file browser, internet browser (just an iframe for fun), and a few other apps to discover.<p>The environment supports uploading and downloading data from the virtual filesystem, along with support for JavaScript programming within ACME and an API for building GUI apps within DWS OS and interacting with the OS DOM. Lastly, you can export and import the state of your OS as a JSON to share with others! Check out the `examples&#x2F;` directory!<p>I&#x27;d love to hear your feedback and suggestions and see if you build anything interesting within the OS, thanks!

[Other] Oq: Terminal OpenAPI Spec Viewer

[Other] Astrophysics Source Code Library

[Other] Show HN: I made a generative online drum machine with ClojureScript After two years of development, I&#x27;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&#x27;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&#x27;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 &quot;blank canvas&quot; 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&#x2F;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&#x27;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&#x27;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&#x27;s virtual DOM, which makes managing the Web Audio API much cleaner. If you&#x27;re building web based audio apps I highly recommend checking out this library.<p>I&#x27;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&#x27;s a video summary: <a href="https:&#x2F;&#x2F;youtu.be&#x2F;qVmEn9z3H24" rel="nofollow">https:&#x2F;&#x2F;youtu.be&#x2F;qVmEn9z3H24</a>

[Other] Rust: A quest for performant, reliable software [video]

[Other] Implementing namespaces and coding standards in WordPress plugin development

[Other] Show HN: I built a tool to find trading signals that aren't just random luck Hi HN,<p>I&#x27;m a solo dev and for the last few months I&#x27;ve been building Hikaro, a tool to find statistically significant trading signals for [e.g., US equities, crypto, forex].<p>I built this to solve my own problem: I was tired of backtests that looked great on paper but failed in practice. Simple metrics like &quot;win rate&quot; can be misleading, so I wanted a way to quickly tell if a signal&#x27;s performance was genuine or just noise.<p>Hikaro ingests daily market data and runs statistical analysis on various trading signals. The goal is to surface signals with strong properties, like:<p>Low p-value: Evidence that the performance is not a random fluke. High Sharpe Ratio: Better risk-adjusted returns. Healthy &#x27;Core Performance&#x27;: The average return after removing the single best outlier trade, for a more conservative view. Other key metrics like Profit Factor and Max Drawdown that you can filter by.<p>I&#x27;m looking for my first users and would love your feedback. I&#x27;m offering a 30-day free trial of the Pro plan (which includes Telegram alerts) with no credit card required.<p>I&#x27;ll be here all day to answer any questions. I&#x27;m especially keen to hear feedback on the concept and the metrics.<p>Thanks, HN!

[API/SDK] Show HN: Pbar.io – Distributed progress bars that work in terminals and browsers I built pbar.io because I was tired of SSH&#x27;ing into servers to check if my data processing scripts were still running, or worse, having them finish&#x2F;crash without knowing.<p>It&#x27;s a simple REST API that lets you create and update progress bars from anywhere. The same progress bar can be viewed as terminal output (with ANSI colors), in a browser, or consumed as JSON.<p>I&#x27;m actually tracking this HN discussion with pbar. The progress bar increases with each comment - watch it live as we discuss!<p>Web: <a href="https:&#x2F;&#x2F;pbar.io&#x2F;Y8yg3BG" rel="nofollow">https:&#x2F;&#x2F;pbar.io&#x2F;Y8yg3BG</a> Terminal: curl <a href="https:&#x2F;&#x2F;pbar.io&#x2F;api&#x2F;bars&#x2F;Y8yg3BG" rel="nofollow">https:&#x2F;&#x2F;pbar.io&#x2F;api&#x2F;bars&#x2F;Y8yg3BG</a><p>More features that emerged from my own use cases: - Hierarchical progress bars (parent bars auto-aggregate children) - Python package (pip install pbar-io) that wraps tqdm - just swap the import - QR codes to monitor progress on your phone while away from desk - No auth required for quick prototypes<p>Curious what use cases you might have for this!