The best Hacker News stories from Show from the past week

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Show HN: WalletWallet – create Apple passes from anything

I got my Apple developer certificate and built a simple app to solve a problem I had. One shop I buy from doesn't have Apple Wallet passes. Since you need signed certificates to build these very simple things, I created a minimal app that signs them. It's available if you need it too. It won't scan cards with AI - you manually enter the barcode, which I think makes it less prone to error.

Show HN: Books mentioned on Hacker News in 2025

Carolina Cloud – One third the cost of AWS for data science workloads

We're Carolina Cloud - managed data science infrastructure at ~1/3 the cost of AWS.<p>I left my job earlier this year after watching companies get crushed by cloud bills for workloads that didn't need hyperscaler complexity. Some examples from my previous life: - $1k/month for a basic 16 vCPU VM - $50k/month for a high-RAM instance - Over $1k/month for notebook platform start-stop execution<p>We built Carolina Cloud for data scientists and small teams who need serious compute without the sticker shock. Our sweet spot: if you're running VMs, notebooks, or RStudio and not deeply tied to AWS/Azure/GCP service ecosystems, we can save you a lot of money.<p>What we offer: - Standard Ubuntu VMs - One-click Marimo notebooks - One-click RStudio Server and Shiny hosting - S3-compatible object storage (launching soon) - Prepay discounts for commitments as short as 2 weeks - SOC2-certified, HIPAA-compliant datacenter in Charlotte, NC<p>Simple pricing: $0.005/vCPU/hr, $0.005/GiB RAM/hr, and $0.0001/GiB of hot storage/hr on AMD EPYC Turin processors. A 32 vCPU, 128GB RAM instance runs ~$240/month vs $800+ on AWS.<p>We're not trying to replicate every AWS service - if you need Lambda + Secrets Manager + S3 with pre-signed URLs, stick with AWS. But if you're a hedge fund running backtests, a biotech team analyzing genomics data, or a researcher who just needs a beefy VM without surprise egress fees, we're 1/3 the price.<p>Check us out at console.carolinacloud.io - happy to answer questions about our infrastructure, pricing, or why we think there's room for regional clouds built on owned hardware.

Show HN: HN Wrapped 2025 - an LLM reviews your year on HN

I was looking for some fun project to play around with the latest Gemini models and ended up building this :)<p>Enter your username and get:<p>- Generated roasts and stats based on your HN activity 2025<p>- Your personalized HN front page from 2035 (inspired by a recent Show HN [0])<p>- An xkcd-style comic of your HN persona<p>It uses the latest gemini-3-flash and gemini-3-pro-image (nano banana pro) models, which deliver pretty impressive and funny results.<p>A few examples:<p>- dang: <a href="https://hn-wrapped.kadoa.com/dang" rel="nofollow">https://hn-wrapped.kadoa.com/dang</a><p>- myself: <a href="https://hn-wrapped.kadoa.com/hubraumhugo" rel="nofollow">https://hn-wrapped.kadoa.com/hubraumhugo</a><p>Give it a try and share yours :)<p>Happy holidays!<p>[0] <a href="https://news.ycombinator.com/item?id=46205632">https://news.ycombinator.com/item?id=46205632</a>

Show HN: Jmail – Google Suite for Epstein files

Hi everyone! My name's Luke and I made the original Jmail here alongside Riley Walz. We had a ton of friends collaborate on building out more of the app suite last night in lieue of DOJ's "Epstein files" release.<p>Please AMA!

Show HN: TinyPDF – 3kb pdf library (70x smaller than jsPDF)

I needed to generate invoices in a Node.js app. jsPDF is 229KB. I only needed text, rectangles, lines, and JPEG images.<p><pre><code> So I wrote tinypdf: <400 lines of TypeScript, zero dependencies, 3.3KB minified+gzipped. What it does: - Text (Helvetica, colors, alignment) - Rectangles and lines - JPEG images - Multiple pages, custom sizes What it doesn't do: - Custom fonts, PNG/SVG, forms, encryption, HTML-to-PDF That's it. The 95% use case for invoices, receipts, reports, tickets, and labels. GitHub: https://github.com/Lulzx/tinypdf npm: npm install tinypdf</code></pre>

Show HN: Hacker News, but every headline is hysterical clickbait

Show HN: Picknplace.js, an alternative to drag-and-drop

I find that the drag and drop experience can quickly become a nightmare, especially on mobile. To tap, hold, drag, and scroll, all at the same time, is both difficult to achieve, and prone to errors. I've always had in mind this 2-step approach, where picking an element and placing it were two separate steps. So I implemented this basic version to showcase my idea.<p>While it might take more time than a regular drag and drop, the benefit is for people who struggle with holding down the mouse button. With picknplace.js, you only need two clicks and some scrolling.<p>This solution is meant as an experiment, so I'm open to discussion.

Show HN: Stop AI scrapers from hammering your self-hosted blog (using porn)

Alright so if you run a self-hosted blog, you've probably noticed AI companies scraping it for training data. And not just a little (RIP to your server bill).<p>There isn't much you can do about it without cloudflare. These companies ignore robots.txt, and you're competing with teams with more resources than you. It's you vs the MJs of programming, you're not going to win.<p>But there is a solution. Now I'm not going to say it's a great solution...but a solution is a solution. If your website contains content that will trigger their scraper's safeguards, it will get dropped from their data pipelines.<p>So here's what fuzzycanary does: it injects hundreds of invisible links to porn websites in your HTML. The links are hidden from users but present in the DOM so that scrapers can ingest them and say "nope we won't scrape there again in the future".<p>The problem with that approach is that it will absolutely nuke your website's SEO. So fuzzycanary also checks user agents and won't show the links to legitimate search engines, so Google and Bing won't see them.<p>One caveat: if you're using a static site generator it will bake the links into your HTML for everyone, including googlebot. Does anyone have a work-around for this that doesn't involve using a proxy?<p>Please try it out! Setup is one component or one import.<p>(And don't tell me it's a terrible idea because I already know it is)<p>package: <a href="https://www.npmjs.com/package/@fuzzycanary/core" rel="nofollow">https://www.npmjs.com/package/@fuzzycanary/core</a> gh: <a href="https://github.com/vivienhenz24/fuzzy-canary" rel="nofollow">https://github.com/vivienhenz24/fuzzy-canary</a>

Show HN: Sqlit – A lazygit-style TUI for SQL databases

I work mostly in the terminal but found myself constantly switching to bloated GUIs like SSMS only for the simple task of browsing tables and run queries. And I didn't find Existing SQL TUIs intuitive, having to read documentation to learn keybindings and CLI flags to connect. Given I had recently switched to linux, I found myself using vs code's sql database extension. Something was awfully wrong.<p>I wanted something like lazygit for databases – run it, connect, and query and frankly just make it enjoyable to access data.<p><pre><code> Sqlit is a keyboard-driven SQL TUI with: - Context-based keybindings (always visible) - Neovim-like interface with normal and insert mode for query editing - Browse databases, tables, views, stored procedures - Adapters for SQL Server, SQLite, PostgreSQL, Turso & more - SSH tunneling support - Themes (Tokyo Night, Nord, Gruvbox etc.) Inspired by lazygit, neovim and lazysql. Built with Python/Textual. </code></pre> Feedback welcome – especially on which adapters to prioritize next. My vision of sqlit is to make a tool that makes it easy to connect and query data, and to do that, and that thing only, really well.<p><a href="https://github.com/Maxteabag/sqlit" rel="nofollow">https://github.com/Maxteabag/sqlit</a>

Show HN: I made a spreadsheet where formulas also update backwards

Hello HN! I'm happy to release this project today. It's a bidirectional calculator (hence the name bidicalc).<p>I've been obsessed with the idea of making a spreadsheet where you can update both inputs and outputs, instead of regular spreadsheets where you can only update inputs.<p>Please let me know what you think! Especially if you find bugs or good example use cases.

Show HN: Tiny VM sandbox in C with apps in Rust, C and Zig

Show HN: Sim – Apache-2.0 n8n alternative

Hey HN, Waleed here. We're building Sim (<a href="https://sim.ai/">https://sim.ai/</a>), an open-source visual editor to build agentic workflows. Repo here: <a href="https://github.com/simstudioai/sim/" rel="nofollow">https://github.com/simstudioai/sim/</a>. Docs here: <a href="https://docs.sim.ai">https://docs.sim.ai</a>.<p>You can run Sim locally using Docker, with no execution limits or other restrictions.<p>We started building Sim almost a year ago after repeatedly troubleshooting why our agents failed in production. Code-first frameworks felt hard to debug because of implicit control flow, and workflow platforms added more overhead than they removed. We wanted granular control and easy observability without piecing everything together ourselves.<p>We launched Sim [1][2] as a drag-and-drop canvas around 6 months ago. Since then, we've added:<p>- 138 blocks: Slack, GitHub, Linear, Notion, Supabase, SSH, TTS, SFTP, MongoDB, S3, Pinecone, ...<p>- Tool calling with granular control: forced, auto<p>- Agent memory: conversation memory with sliding window support (by last n messages or tokens)<p>- Trace spans: detailed logging and observability for nested workflows and tool calling<p>- Native RAG: upload documents, we chunk, embed with pgvector, and expose vector search to agents<p>- Workflow deployment versioning with rollbacks<p>- MCP support, Human-in-the-loop block<p>- Copilot to build workflows using natural language (just shipped a new version that also acts as a superagent and can call into any of your connected services directly, not just build workflows)<p>Under the hood, the workflow is a DAG with concurrent execution by default. Nodes run as soon as their dependencies (upstream blocks) are satisfied. Loops (for, forEach, while, do-while) and parallel fan-out/join are also first-class primitives.<p>Agent blocks are pass-through to the provider. You pick your model (OpenAI, Anthropic, Gemini, Ollama, vLLM), and and we pass through prompts, tools, and response format directly to the provider API. We normalize response shapes for block interoperability, but we're not adding layers that obscure what's happening.<p>We're currently working on our own MCP server and the ability to deploy workflows as MCP servers. Would love to hear your thoughts and where we should take it next :)<p>[1] <a href="https://news.ycombinator.com/item?id=43823096">https://news.ycombinator.com/item?id=43823096</a><p>[2] <a href="https://news.ycombinator.com/item?id=44052766">https://news.ycombinator.com/item?id=44052766</a>

The highest quality codebase

Show HN: Automated license plate reader coverage in the USA

Built this over the last few days, based on a Rust codebase that parses the latest ALPR reports from OpenStreetMaps, calculates navigation statistics from every tagged residential building to nearby amenities, and tests each route for intersection with those ALPR cameras (Flock being the most widespread).<p>These have gotten more controversial in recent months, due to their indiscriminate large scale data collection, with 404 Media publishing many original pieces (<a href="https://www.404media.co/tag/flock/" rel="nofollow">https://www.404media.co/tag/flock/</a>) about their adoption and (ab)use across the country. I wanted to use open source datasets to track the rapid expansion, especially per-county, as this data can be crucial for 'deflock' movements to petition counties and city governments to ban and remove them.<p>In some counties, the tracking becomes so widespread that most people can't go anywhere without being photographed. This includes possibly sensitive areas, like places of worship and medical facilities.<p>The argument for their legality rests upon the notion that these cameras are equivalent to 'mere observation', but the enormous scope and data sharing agreements in place to share and access <i>millions</i> of records without warrants blurs the lines of the fourth amendment.

Show HN: AlgoDrill – Interactive drills to stop forgetting LeetCode patterns

I built AlgoDrill because I kept grinding LeetCode, thinking I knew the pattern, and then completely blanking when I had to implement it from scratch a few weeks later.<p>AlgoDrill turns NeetCode 150 and more into pattern-based drills: you rebuild the solution line by line with active recall, get first principles editorials that explain why each step exists, and everything is tagged by patterns like sliding window, two pointers, and DP so you can hammer the ones you keep forgetting. The goal is simple: turn familiar patterns into code you can write quickly and confidently in a real interview.<p><a href="https://algodrill.io" rel="nofollow">https://algodrill.io</a><p>Would love feedback on whether this drill-style approach feels like a real upgrade over just solving problems once, and what’s most confusing or missing when you first land on the site.

Show HN: I built a system for active note-taking in regular meetings like 1-1s

Hey HN! Like most here regular meetings have always been a big part of my work.<p>Over the years I've learned the value of active note taking in these meetings. Meaning: not minutes, not transcriptions or AI summaries, but <i>me</i> using my brain to actively pull out the key points in short form bullet-like notes, as the meeting is going on, as I'm talking and listening (and probably typing with one hand). This could be agenda points to cover, any interesting sidebars raised, insights gotten to in a discussion, actions agreed to (and a way to track whether they got done next time!).<p>It's both useful just to track what's going on in all these different meetings week to week (at one point I was doing about a dozen 1-1s per week, and it just becomes impossible to hold it in RAM) but also really valuable over time when you can look back and see the full history of a particular meeting, what was discussed when, how themes and structure are changing, is the meetings effective, etc.<p>Anyway, I've tried a bunch of different tools for taking these notes over the years. All the obvious ones you've probably used too. And I've always just been not <i>quite</i> satisfied with the experience. They work, obviously (it's just text based notes at the end of the day) but nothing is first-class for this usecase.<p>So, I decided to build the tool I've always felt I want to use, specifically for regular 1-1s and other types of regular meetings. I've been using it myself and with friends for a while already now, and I think it's got to that point where I actually prefer to reach for it over other general purpose note taking tools now, and I want to share it more widely.<p>There's a free tier so you can use it right away, in fact without even signing up.<p>If you've also been wanting a better system to manage your notes for regular meetings, give it a go and let me know what you think!

Show HN: Gemini Pro 3 imagines the HN front page 10 years from now

Show HN: Kraa – Writing App for Everything

Hello HN! We're a team of three building a new kind of web-based markdown editor.<p>There are many editors out there, so one is spoiled for choice, but Kraa's approach is a little different. It's trying to be both a minimal and distraction-free experience while being feature-rich and allowing for tons of use cases.<p>What Kraa's good for:<p>- Distraction-free writing & reading (minimal UI, performant, styling logic completely separated from the editing experience)<p>- Quick sharing of any written text – compared to many other writing tools, your content can be easily shared just by posting a link and giving 'read' or 'edit' access (we also have password-protection)<p>- Real-time chat / communities – Kraa has some unique features around real-time editing and our Chat widget allows for a frictionless chat experience. No send button.<p>- Kraa works well on mobile (though dedicated apps are planned)<p>---<p>Demo examples (all live, no login needed):<p>Blog article: <a href="https://kraa.io/kraa/examples/echolibrary" rel="nofollow">https://kraa.io/kraa/examples/echolibrary</a><p>Long-form story: <a href="https://kraa.io/kraa/examples/insidekick" rel="nofollow">https://kraa.io/kraa/examples/insidekick</a><p>Magazine: <a href="https://kraa.io/weeklyinspiration" rel="nofollow">https://kraa.io/weeklyinspiration</a><p>Kraa is built on top of ProseMirror (and TipTap) and Svelte.<p>You don’t need an account to try Kraa. We’d really appreciate your thoughts and feedback!

Show HN: HCB Mobile – financial app built by 17 y/o, processing $6M/month

Hey everyone! I just built a mobile app using Expo (React Native) for a platform that moves $6M/month. It’s a neobank used by 6,500+ nonprofit organizations across the world.<p>One of my biggest challenges, while juggling being a full-time student, was getting permission from Apple/Google to use advanced native features such as Tap to Pay (for in-person donations) and Push Provisioning (for adding your card to your digital wallet). It was months of back-and-forth emails, test case recordings, and also compliance checks.<p>Even after securing Apple/Google’s permission, any minor fix required publishing a new build, which was time-consuming. After dealing with this for a while, I adopted the idea of “over the air updates” using Expo’s EAS update service. This allowed me to remotely trigger updates without needing a new app build.<p>The 250 hours I spent building this app were an INSANE learning experience, but it was also a whole lot of fun. Give the app a try, and I’d love any feedback you have on it!<p>btw, back in March, we open-sourced this nonprofit neobank on GitHub. <a href="https://news.ycombinator.com/item?id=43519802">https://news.ycombinator.com/item?id=43519802</a>