Hey everyone! I just built a mobile app using Expo (React Native) for a platform that moves $6M&#x2F;month. It’s a neobank used by 6,500+ nonprofit organizations across the world.One of my biggest challenges, while juggling being a full-time student, was getting permission from Apple&#x2F;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.Even after securing Apple&#x2F;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.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!btw, back in March, we open-sourced this nonprofit neobank on GitHub.
<a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=43519802">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=43519802</a>

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

I&#x27;ve been having fun building out a really simple chess learning app for my daughter (7). It started with just &quot;maze like&quot; puzzles [1] and I&#x27;ve added a few more.This &quot;radioactive pooping knights&quot; idea came from an Irish primary school chess website [2]. Really simple idea, two knights moving around the board leaving poo behind... Don&#x27;t be the one forced to step on it.* best played with sound on.[1]. <a href="https:&#x2F;&#x2F;minichessgames.com&#x2F;#&#x2F;movement&#x2F;knight" rel="nofollow">https:&#x2F;&#x2F;minichessgames.com&#x2F;#&#x2F;movement&#x2F;knight</a>[2]. <a href="https:&#x2F;&#x2F;ficheall.ie&#x2F;" rel="nofollow">https:&#x2F;&#x2F;ficheall.ie&#x2F;</a> *highly subjective, may not be better for you to play with sound at all ;)p.s. Any &quot;buy me a coffee&quot; goes to my daughter. Annoyingly they only pay out once you get above $10 USD and I think it&#x27;s currently sitting at 9.85 or something!

Show HN: Radioactive Pooping Knights

Hello HN! We&#x27;re a team of three building a new kind of web-based markdown editor.There are many editors out there, so one is spoiled for choice, but Kraa&#x27;s approach is a little different. It&#x27;s trying to be both a minimal and distraction-free experience while being feature-rich and allowing for tons of use cases.What Kraa&#x27;s good for:- Distraction-free writing &amp; reading (minimal UI, performant, styling logic completely separated from the editing experience)- 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 &#x27;read&#x27; or &#x27;edit&#x27; access (we also have password-protection)- Real-time chat &#x2F; communities – Kraa has some unique features around real-time editing and our Chat widget allows for a frictionless chat experience. No send button.- Kraa works well on mobile (though dedicated apps are planned)---Demo examples (all live, no login needed):Blog article: <a href="https:&#x2F;&#x2F;kraa.io&#x2F;kraa&#x2F;examples&#x2F;echolibrary" rel="nofollow">https:&#x2F;&#x2F;kraa.io&#x2F;kraa&#x2F;examples&#x2F;echolibrary</a>Long-form story: <a href="https:&#x2F;&#x2F;kraa.io&#x2F;kraa&#x2F;examples&#x2F;insidekick" rel="nofollow">https:&#x2F;&#x2F;kraa.io&#x2F;kraa&#x2F;examples&#x2F;insidekick</a>Magazine: <a href="https:&#x2F;&#x2F;kraa.io&#x2F;weeklyinspiration" rel="nofollow">https:&#x2F;&#x2F;kraa.io&#x2F;weeklyinspiration</a>Kraa is built on top of ProseMirror (and TipTap) and Svelte.You don’t need an account to try Kraa. We’d really appreciate your thoughts and feedback!

Show HN: Kraa – Writing App for Everything

I&#x27;m sure folks here have seen pastebins a thousand times. There&#x27;s no innovation left in this space – and that&#x27;s kind of the point.When I wanted to self-host a pastebin, every option I found was too much. Git-based version control, OAuth, elaborate admin panels. I just wanted something I could deploy in under a minute with a CLI that actually works.So I built pbnj (yes, like the sandwich).What it is:- A minimal, beautiful pastebin with syntax highlighting for 100+ languages- One-click deploy to Cloudflare (free tier gives you ~100,000 pastes)- CLI-first: pbnj file.py → get a URL, copied to clipboard- Memorable URLs: crunchy-peanut-butter-sandwich instead of x7f9a2- Private pastes with optional secret keys- Web UI for when you&#x27;re not in a terminalWhat it isn&#x27;t:- No accounts, no OAuth, no git integration- No multi-user support (fork it and run your own)- No expiring pastes, no folders, no comments- Not trying to replace Gist or be a &quot;platform&quot;Why not just use Gist? Maybe you want to own your data. Maybe you enjoy self-hosting things. Or maybe you&#x27;re a little autistic like me and just like having your own stuff.Live demo: <a href="https:&#x2F;&#x2F;pbnj.sh" rel="nofollow">https:&#x2F;&#x2F;pbnj.sh</a>
GitHub: <a href="https:&#x2F;&#x2F;github.com&#x2F;bhavnicksm&#x2F;pbnj" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;bhavnicksm&#x2F;pbnj</a>
CLI: npm install -g @pbnjs&#x2F;cliIf this scratches an itch for you, I&#x27;d appreciate a star on GitHub. Happy to answer any questions!

Show HN: Pbnj – A minimal, self-hosted pastebin you can deploy in 60 seconds

AI coding assistants are productive but sloppy. They produce code that looks right but:- Imports packages that don&#x27;t exist
 - Uses placeholder functions that do nothing
 - Leaks patterns from JavaScript, Java, Ruby into Python
 - Leaves behind dead code and duplicates
 - Uses mutable default argumentsI built sloppylint to catch these &quot;AI slop&quot; patterns before they hit production.<pre><code> pip install sloppylint
 sloppylint .
</code></pre>
It detects 100+ patterns across categories:
 - Hallucinated imports (20% of AI imports reference non-existent packages)
 - Placeholder code (`pass`, `...`, `TODO`)
 - Wrong-language patterns (.push(), .equals(), .forEach())
 - Mutable defaults, bare excepts, dead codeThis isn&#x27;t a replacement for traditional linters - it catches the specific mistakes AI makes that humans wouldn&#x27;t.<a href="https:&#x2F;&#x2F;github.com&#x2F;rsionnach&#x2F;sloppylint" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;rsionnach&#x2F;sloppylint</a>

Show HN: Sloppylint – A linter for AI-generated Python code

Show HN: Tacopy – Tail Call Optimization for Python

Show HN: I was reintroduced to computers: Raspberry Pi

Show HN: Onlyrecipe 2.0 – I added all features HN requested – 4 years later

Show HN: SerpApi MCP Server

Show HN: Walrus – a Kafka alternative written in Rust

Show HN: MTXT – Music Text Format

I built it for myself. After a lot of iterations, this is getting some traction.It helps me organize my personal life.Still trying to figure out what else it needs to do, and what can be improved.Please provide feedback!

Show HN: A new AI driven task management tool

BinaryStorage is a PHP binary key&#x2F;value store designed for fast and efficient data access.
It supports any PHP serializable data, provides startsWith&#x2F;contains searches, and includes data compaction to reduce disk usage.GitHub: <a href="https:&#x2F;&#x2F;github.com&#x2F;olivier-ls&#x2F;binary-storage-php" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;olivier-ls&#x2F;binary-storage-php</a>

Show HN: BinaryStorage – High-performance PHP binary key/value store

I got back into church a couple years ago and would try taking notes with Apple Notes. It was a struggle trying to type notes while focusing on the sermon. Honestly, it would have been easier to write it in a notebook but in the end I built this iOS app to solve that problem.You can record audio during a sermon (or upload files), and it transcribes using Whisper, then generates summaries, flashcards, and reflection questions tailored to Christian content.The backend is Spring Boot + Kotlin calling OpenAI&#x27;s API. Instead of deploying the backend through one of the cloud providers directly I decided to go with Railway. Users are notified with push notifications when their transcription and summary are completed. The iOS app uses SwiftUI and out-of-the-box SwiftUI components.I worked with Spring Boot + Java a few years back when in fintech so it was cool to try writing something in Kotlin. I&#x27;m also a full-time Flutter dev that has been trying to get into Native iOS development and felt like I found a good use case for an app.Currently only available in the US&#x2F;Canada App Store. There is a free 3-day trial that you can use to give the app a go.The goal was helping Christians retain more from sermons and build stronger biblical literacy.Happy to answer questions about the architecture, AI prompting approach for Christian content, or anything else.App Store link: <a href="https:&#x2F;&#x2F;apps.apple.com&#x2F;us&#x2F;app&#x2F;bible-note-journal&#x2F;id6752273302">https:&#x2F;&#x2F;apps.apple.com&#x2F;us&#x2F;app&#x2F;bible-note-journal&#x2F;id675227330...</a>

Show HN: Bible Note Journal – AI transcription and study tools for sermons (iOS)

My team and I built Haven. It is a stripped down browser that only connects to verified financial institutions and blocks everything else. No extensions, no injected scripts, no overlays, no random third party code. It is not a general browser, it is just a controlled environment for banking and investing.Why? I have spent years building browser extensions and know exactly how much power they have. The extension model is useful, but the security model is too loose and a single malicious install can see everything, rewrite everything, and mislead a user without leaving a trace. My dad learned that the hard way after installing a fake Zoom extension and then losing money from his banking account.In addition to my dad’s story, the number of people adding AI into their current browsers or using AI native browsers is growing and offers amazing capabilities, but the risks are growing exponentially. I wanted to build a way for him and for anyone, from sophisticated users to normal users, to bank safely.It is currently free for consumers as we learn how people use it and determine a future revenue model for providing secure sessions. At our core we believe in privacy, which is the reason we are building this product. We are funded by trusted and established investors including Google Ventures, Valley Capital Partners, and others.If you want to try it the app is at <a href="https:&#x2F;&#x2F;starthaven.com" rel="nofollow">https:&#x2F;&#x2F;starthaven.com</a>.Looking for people to test this out, get product feedback and feature requests!

Show HN: Haven – Banking needs a safer browser

When I bought my home, the big bank I&#x27;d been using for years quoted me 7% APR. A local credit union was offering 5.5% for the exact same mortgage.I was surprised until I learned that mortgages are basically standardized products – the government buys almost all of them (see Bits About Money: <a href="https:&#x2F;&#x2F;www.bitsaboutmoney.com&#x2F;archive&#x2F;mortgages-are-a-manufactured-product&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.bitsaboutmoney.com&#x2F;archive&#x2F;mortgages-are-a-manuf...</a>). So what&#x27;s the price difference paying for? A recent Bloomberg Odd Lots episode makes the case that it&#x27;s largely advertising and marketing (<a href="https:&#x2F;&#x2F;www.bloomberg.com&#x2F;news&#x2F;audio&#x2F;2025-11-28&#x2F;odd-lots-this-is-why-credit-card-rates-are-so-high-podcast" rel="nofollow">https:&#x2F;&#x2F;www.bloomberg.com&#x2F;news&#x2F;audio&#x2F;2025-11-28&#x2F;odd-lots-thi...</a>). Credit unions are non-profits without big marketing budgets, so they can pass those savings on, but a lot of people don&#x27;t know about them.I built this dashboard to make it easier to shop around. I pull public rates from 120+ credit union websites and compares against the weekly FRED national benchmark.Features:- Filter by loan type (30Y&#x2F;15Y&#x2F;etc.), eligibility (the hardest part tbh), and rate type
- Payment calculator with refi mode (CUs can be a bit slower than big lenders, but that makes them great for refi)
- Links to each CU&#x27;s rates page and eligibility requirements
- Toggle to show&#x2F;hide statistical outliersAt the time of writing, the average CU rate is 5.91% vs. 6.23% national average. about $37k difference in total interest on a $500k loan. I actually used seaborn to visualize the rate spread against the four big banks: <a href="https:&#x2F;&#x2F;www.reddit.com&#x2F;r&#x2F;dataisbeautiful&#x2F;comments&#x2F;1pcj9t7&#x2F;oc_the_high_cost_of_big_banks_i_tracked_daily&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.reddit.com&#x2F;r&#x2F;dataisbeautiful&#x2F;comments&#x2F;1pcj9t7&#x2F;oc...</a>Stack: Python for the data&#x2F;backend, Svelte&#x2F;SvelteKit for the frontend. No signup, no ads, no referral fees.Happy to answer questions about the methodology or add CUs people suggest.

Show HN: I built a dashboard to compare mortgage rates across 120 credit unions

I built Codesprint because I realized my raw WPM on standard typing tests didn&#x27;t translate to coding. My muscle memory for prose was fine, but I was slow with brackets, semicolons, and indentation; the stuff that actually matters in a technical interview.Codesprint is a typing tool specifically for code syntax. Instead of random words, it uses real LeetCode snippets (Two Sum, LRU Cache, etc.) so you&#x27;re practicing realistic patterns.The Tech: It’s built with Next.js, TypeScript, Chakra UI, and Framer Motion.One interesting challenge was the scoring logic (lib&#x2F;scoring.ts). Standard WPM assumes a word is 5 characters, but code is dense with symbols. I had to tweak the engine to handle indentation and &quot;perfect word&quot; streaks correctly to give a metric that actually feels fair for code.I currently support Python, Java, C++, and JS. I’m looking to add Rust and Go next.I’d love feedback on the typing &quot;feel&quot;, specifically how the engine handles auto-indentation vs manual tabbing.Thanks!

Show HN: Codesprint – A typing game for practicing coding interview syntax

I built Fresh to challenge the status quo that terminal editing must require a steep learning curve or endless configuration. My goal was to create a fast, resource-efficient TUI editor with the usability and features of a modern GUI editor (like a command palette, mouse support, and LSP integration).Core Philosophy:- Ease-of-Use: Fundamentally non-modal. Prioritizes standard keybindings and a minimal learning curve.- Efficiency: Uses a lazy-loading piece tree to avoid loading huge files into RAM - reads only what&#x27;s needed for user interactions. Coded in Rust.- Extensibility: Uses TypeScript (via Deno) for plugins, making it accessible to a large developer base.The Performance Challenge:I focused on resource consumption and speed with large file support as a core feature. I did a quick benchmark loading a 2GB log file with ANSI color codes. Here is the comparison against other popular editors:<pre><code> - Fresh: Load Time: *~600ms* | Memory: *~36 MB*
 - Neovim: Load Time: ~6.5 seconds | Memory: ~2 GB
 - Emacs: Load Time: ~10 seconds | Memory: ~2 GB
 - VS Code: Load Time: ~20 seconds | Memory: OOM Killed (~4.3 GB available)
</code></pre>
(Only Fresh rendered the ansi colors.)Development process:I embraced Claude Code and made an effort to get good mileage out of it. I gave it strong specific directions, especially in architecture &#x2F; code structure &#x2F; UX-sensitive areas. It required constant supervision and re-alignment, especially in the performance critical areas. Added very extensive tests (compared to my normal standards) to keep it aligned as the code grows. Especially, focused on end-to-end testing where I could easily enforce a specific behavior or user flow.Fresh is an open-source project (GPL-2) seeking early adopters. You&#x27;re welcome to send feedback, feature requests, and bug reports.Website: <a href="https:&#x2F;&#x2F;sinelaw.github.io&#x2F;fresh&#x2F;" rel="nofollow">https:&#x2F;&#x2F;sinelaw.github.io&#x2F;fresh&#x2F;</a>GitHub Repository: <a href="https:&#x2F;&#x2F;github.com&#x2F;sinelaw&#x2F;fresh" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;sinelaw&#x2F;fresh</a>

Show HN: Fresh – A new terminal editor built in Rust

It all started as an experiment to see if I could build a game making heavy use of Deno and its SQLite driver. After sharing an early build in the „What are you working on?“ thread here, I got the encouragement I needed to polish it and make a version 1.0 for Steam.So here it is, Microlandia, a SimCity Classic-inspired game with parameters from real-life datasets, statistics and research. It also introduces aspects that are conveniently hidden in other games (like homelessness), and my plan is to continue updating, expanding and perfecting the models for an indefinite amount of time.

Show HN: Microlandia, a brutally honest city builder

Hi HN,I&#x27;m Rosa, a massage therapist for over 30 years. I noticed my clients felt relaxed after a massage, but their stress and muscle tension always came back. A one-hour massage isn&#x27;t always enough to combat a long workweek.I saw that people needed info on how to take care of their bodies between appointments, not just treatment.That&#x27;s why we built MASSAGE BY ROSA – a wellness platform to meet this need.Here’s what we offer:It’s a two-part deal:-Massage Therapy: Hands-on therapy for pain relief – based on methods from South Florida.-Online Body Therapy Courses: This is what I want to share. I turned my knowledge into video courses teaching self-massage, workstation adjustments, and ways to release tension. It’s like having a therapist help you stay well.The Tech:We’re keeping it basic with a static site for course content and subscriptions, which lets us focus on making great video lessons.We&#x27;re launching this to solve the problem of upkeep in physical wellness. It&#x27;s for people who sit a lot and want lasting relief without constant professional help.Check it out and tell me what you think:Landing Page: <a href="https:&#x2F;&#x2F;massagebyrosa.com" rel="nofollow">https:&#x2F;&#x2F;massagebyrosa.com</a>I’m here to answer any questions about the platform, the methods, or how the business runs!

Show HN: Massage therapy meets online learning– an app to help maintain wellness

Show HN: Vibe Commander

Hi HN,I built a tiny tool because I couldn’t find a clean, distraction-free monthly planner that:1. shows a clean monthly task view
2. doesn’t require an account
3. doesn’t sync or store anything online
4. works offline
5. is printable
6. and keeps a minimal, distraction-free aestheticSo I made <a href="https:&#x2F;&#x2F;printcalendar.top&#x2F;" rel="nofollow">https:&#x2F;&#x2F;printcalendar.top&#x2F;</a>
 — a minimal monthly task planner.It’s intentionally simple. No logins, no integrations, no dashboards.
Just a small tool for people who want structure without clutter.

Show HN: A Minimal Monthly Task Planner (printable, offline, no signup)

Show HN: ChatGPT App That Solves LLM Randomness Problem No One Talks About

Hey HN,
I&#x27;ve just launched <a href="https:&#x2F;&#x2F;bananaprompts.fun&#x2F;" rel="nofollow">https:&#x2F;&#x2F;bananaprompts.fun&#x2F;</a>, a collection of carefully crafted prompts designed specifically for Nano Banana Pro, the AI model that excels at advanced image generation. Whether you&#x27;re into photorealistic seascapes, cyberpunk portraits, or isometric claymation cityscapes, these prompts are optimized to help you create stunning visuals with minimal tweaking.It&#x27;s built for AI creators, artists, and devs who want reliable starting points to experiment with Nano Banana Pro. I&#x27;d love your feedback on the prompts, UI, or ideas for expansion—maybe more categories or community submissions?Check it out and let me know what you think!

Show HN: Banana Prompts – Curated Prompts for Nano Banana Pro

Hey there! I just finished a youtube video explaining our donut chess in detail: <a href="https:&#x2F;&#x2F;youtu.be&#x2F;iRcfHCPFgkM" rel="nofollow">https:&#x2F;&#x2F;youtu.be&#x2F;iRcfHCPFgkM</a>So I thought it&#x27;d be cool to show it off here too- it can be played around with at mchess.io&#x2F;donut - you can also set up an AI or online game on the site.This is all indie dev work from a couple friends and myself.

Show HN: Chess on a Donut/Torus and Deep-Dive

Got tired of wiring up vector stores, embedding models, and chunking logic every time I needed RAG. So I built piragi.<pre><code> from piragi import Ragi

 kb = Ragi(\[&quot;.&#x2F;docs&quot;, &quot;.&#x2F;code&#x2F;\*\*&#x2F;\*.py&quot;, &quot;https:&#x2F;&#x2F;api.example.com&#x2F;docs&quot;\])

 answer = kb.ask(&quot;How do I deploy this?&quot;)
</code></pre>
That&#x27;s the entire setup. No API keys required - runs on Ollama + sentence-transformers locally.What it does:<pre><code> - All formats - PDF, Word, Excel, Markdown, code, URLs, images, audio

 - Auto-updates - watches sources, refreshes in background, zero query latency

 - Citations - every answer includes sources

 - Advanced retrieval - HyDE, hybrid search (BM25 + vector), cross-encoder reranking

 - Smart chunking - semantic, contextual, hierarchical strategies

 - OpenAI compatible - swap in GPT&#x2F;Claude whenever you want
</code></pre>
Quick examples:<pre><code> # Filter by metadata
 answer = kb.filter(file_type=&quot;pdf&quot;).ask(&quot;What&#x27;s in the contracts?&quot;)

 #Enable advanced retrieval

 kb = Ragi(&quot;.&#x2F;docs&quot;, config={
 &quot;retrieval&quot;: {
 &quot;use_hyde&quot;: True,
 &quot;use_hybrid_search&quot;: True,
 &quot;use_cross_encoder&quot;: True
 }
 })


 # Use OpenAI instead 
 kb = Ragi(&quot;.&#x2F;docs&quot;, config={&quot;llm&quot;: {&quot;model&quot;: &quot;gpt-4o-mini&quot;, &quot;api_key&quot;: &quot;sk-...&quot;}})
</code></pre>
Install:<pre><code> pip install piragi
 PyPI: https:&#x2F;&#x2F;pypi.org&#x2F;project&#x2F;piragi&#x2F;
</code></pre>
Would love feedback. What&#x27;s missing? What would make this actually useful for your projects?

Show HN: RAG in 3 Lines of Python

Show HN: Mirror_bridge – C++ Reflection powered Python binding generation

Show HN: I built a Python library for central bank economic announcement data

Author here: I built this because I wanted to learn about CBOR and how it&#x27;s build and how it encodes data. I work with it on a almost daily basis, its s binary format that is defined in the RFC8949 specification.It was my first time using AI to formalize the rules from an RFC and turn them into testable, working code. That&#x27;s why I also explicitly say that this tool is not currently in use for production (I&#x27;m sure it will contain bugs!), it&#x27;s just like a tinkering tool for me and at one point I hope to make this into something that people can maybe even use in their production system.For visualization, I built a hex viewer that shows how the CBOR is decoded. It&#x27;s really helping me understand the format better.Right now it&#x27;s just a basic version—you can encode, decode, and diff two CBOR values. There&#x27;s still a lot of work to do. I&#x27;d like to add more educational content about what CBOR actually is and offer more tools.I work in the Cardano space where CBOR is used heavily, so one thing I want to add is a function that can recognize which Cardano era a transaction (or part of a transaction) comes from.There is still a ton of work to do and I have more ideas in mind, but for now that&#x27;s my first version and I would like to get some feedback :)The CBOR parser for that project is already open sourced, and I also built a small test suite to validate my CBOR parser against test cases and see how I compare to different parsers. That&#x27;s why I created two projects that make this app possible. They are both linked in the about page and they&#x27;re called Nachos and Taco.

Show

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