Ask HN: What Are You Working On? (April 2026)

I have been working on two opensource tools:

https://dhuan.github.io/mock/latest/examples.html

^Command line utility that lets you build APIs with just one command.

https://github.com/dhuan/dop

^JSON/YAML manipulation with AWK style approach.

Working on Kernel, a GSAT vocab study app for Taiwanese students. A lot of exam prep still means paying cram schools for structure and linear repetition. We’re trying to turn that structure into software that knows what you’re about to forget and what to review next.

app store: https://apps.apple.com/tw/app/kernel-%E8%83%8C%E5%96%AE%E5%A...

viral launch post that brought in ~1700 users in 2 days: https://www.threads.com/@sean_hsu_13/post/DW8nBzDjV8T?xmt=AQ...

https://tessellate-digital.github.io/notion-agent-hive/

I'm not a fan of the TUI form factor for longer running, more ambitious features. Even with a classic "Add an endpoint, tweak the infra, consume in the frontend", plans get awkward to refine in markdown files, especially if everything lives in its own repo.

I wanted something like Plannotator, that could also work for the execution, not just the planning, So I've been working on something that turns Notion into the memory and orchestration layer for agents.

Underneath, it's a plan-implement-review loop, but you get a nice Notion page with a kanban board out of it. You can easily link your existing documentation, collaborate by sharing the page, annotate and comment to steer the planner, and you get versioning out of the box.

Because Notion acts as the memory, you can just open the page after a long weekend and get your agent and yourself back into the full context. You can see what's been done, what's left, or what requires human input just by looking at the board. You can ask it to fetch the comments on the pull request you raised, and it'll fetch, validate the comments, give you a report, and update the plan/board if necessary.

I've been using it exclusively for the last two weeks, I'm quite happy with it. It's been really fun to build the exact tool I wanted.

https://www.crowdsupply.com/t76-org/dr-pd

Dr. PD is an open-source USB-C Power Delivery analyzer and programmable sink. It can sit inline between a USB-PD source and sink to show you the communication between them, or connect directly to a source and emulate a sink so you can characterize chargers and power supplies.

The goal of the project is to make serious USB-PD analysis more accessible. The hardware, firmware, and host software are all open source. The control software runs locally in Chrome or Edge with no drivers or installation required, and the platform also provides Python, JavaScript, SCPI, and USBTMC interfaces for automation.

(Sorry that I don't have a link to the GH repo yet, but you can follow the project on https://hackaday.io/project/205495-dr-pd. Also, if you read this far, I'm looking for a few beta testers. Reach out if you're interested!)

A cyberpunk 2077 inspired Tower Defence game https://github.com/XEonAX/TowerPunk-CyberDefence

I had already developed a tower defence game without AI long time back.

Wanted to try my hand at guided vibe engineering and see how faster was it.

I built my own fun t-shirt brand called devopsicorn, no AI used here, I worked with a graphics designer from Spain: https://devopsicorn.com

Fun project playing around with print in demand and Etsy. Now wondering why Etsy became so popular while being tricky and inflexible to use for the seller :-)

I am working on making grocery online shopping less overwhelming and more like a rolling list, you keep adding items as you see them (missing) in your household and it silently records it at the backend. When you are ready to pick up order, you push to qfc cart via api (a button) and boom your grocery shopping is done. No need of making lists and then one by one putting them on the cart. It works with any QFC or Kroger store because to my disbelieve they actually have an open sku and cart api. Grateful to Kroger to be tech forward. Free to use , here is the link https://www.ddisco.com/sonic/customer My wife is hooked on it as she had to take time in the week to sit down ask me what to order and then build the cart. Now it’s like just typing in what you need.

Next I am making the version for folks who do not make a list and just go with past orders , for them I am automating so the cart is made based on past orders like milk usually is ordered every 2 weeks.

Creating interactive pivot tables from large relational tables.

Many people know that a handy data analysis feature in Excel is to create a pivot table from a spreadsheet. But spreadsheets are limited to just a million rows. You can get around this limit by jumping through a bunch of hoops.

My system lets you easily create tables with thousands of columns and hundreds of millions of rows. (Just drop a CSV, Json, or other file on a window to create a table.)

Now you can create a pivot table from it with just a few clicks of the mouse. It is fast (I created a pivot table against an 8.5 million row table of Chicago crime data in less than a second.)

The resulting pivot table is interactive. Each cell (row/column intersection) has all the row keys mapped to it. Double-click on any cell and it will instantly show you all the rows in the original table that were used to calculate the cell. You can then analyze those rows further.

It also works well against much larger tables. I have tested it out against 25M, 50M, 100M, and 200M+ row tables.

Just recently launched my suite of media inspection and encoding tools based on FFmpeg.

https://video-commander.com.

Still iterating through refinement and features. It's built on Rust + Tauri with a React frontend, in case anyone is curious.

I've created various open-source and commercial tools in the multimedia space over the last 10+ years and wanted to put it all together into something more premium.

I am building devlens.io, an open source tool for codebase visualization tool for easy onboarding and easy PR review. The most interesting and loved feature of the tool is blast radius i.e., If I change this component, how far will the effect be propogated ?

github repo if you wanna check : https://github.com/devlensio/devlensOSS website : https://devlens.io

I'm researching Luddite-style examples from around the world. That is, examples of when people rebel against new technology that they see as harming their livelihoods.

https://easel.games

For the past 4 years I've been building a programming language reimagined specifically for games. It has automatic multiplayer, but also things like state, components, concurrent behaviours and reactive user interfaces baked into the language.

Built/building godom, a framework that lets me build local apps in Go, with the browser serving as a dumb view layer. I don't hate JavaScript or React, but my primary motivation was to eliminate NPM as much as possible. https://github.com/anupshinde/godom I used AI to create the first POC, and once it was proven, it was improved, and AI handled a lot of grunt work where it could. The framework was built primarily to solve my pain points

And building Fractiz.com, a customizable pre-coded backtests platform.

I helped co-host a popup village in rural South Korea last week. Mix of co-working, co-living and local activities like trail running and bird watching.

Post-event feedback showed everyone loved it. But personally I think we could have done better organizing on the co-working side so people has a more predictable schedule to lock-in.

So I’m planning what the next iteration of this event could look like if the co-working aspect was stronger. Especially in the area of everyone sharing their personal and/or professional intentions with each other. So they're more likely to accomplish those intentions with the help of other participants.

https://protoville.xyz

https://github.com/Realman78/Kiyeovo - I'm currently working towards the full release of my P2P dual-network mode messenger which is currently in beta. The reviews were overwhelmingly positive when I released the beta a week ago so that motivated me to try extra hard to make it pseudo-perfect upon full release

I've got a couple of different things going as per usual, but the one that I'm currently most excited about is Lotus Eater:

https://lotuseater.epiccoleman.com/

It's a mostly vibe-coded fan site for jamtronica greats Lotus. I wrote/prompted a scraper to pull in setlist data from Nugs and have been having a lot of fun coming up with cool data analysis stuff to do with their sets.

I've seen them 7 times (chump change compared to some fans) and was starting to get certain intuitions about like, "if I hear song X that probably means they won't play song Y." For example, one of my favorite Lotus tunes, It's All Clear To Me Now, seems to fulfill a similar "function" as another song - Did Fatt.

It was pretty cool to see that intuition bear out in the data (they've only ever been played in the same show one time in over 900 total shows).

I've got a bunch of other "data" features sitting in a PR in my Gitlab, need to get around to reviewing and testing it so I can push out the next update. Also have a few other ideas for it, although I think there's probably a point coming fairly soon where there's not really anything left to do.

I posted it on the main Lotus fan group on Facebook. I have a grand total 8 users. I love those users.

The site is nothing crazy, it will never make money or anything - but it's just been a ton of fun to have something cool to hack around on.

I’m working on my own markdown IDE / Google Docs competitor with an AI agentic editor that coaches on strategy in addition to proof reading. I made it as a side project. Designed it entirely by taking screenshots, annotating them, and giving feedback to codex. Basically applied everything I learned utilizing Claude code a d codex extensively at work to this side project to see how fast I could ship something that felt complete. Check it out: https://clarus.page

I've been working on proving that Claude Opus can be self-reflecting meaning that its attention and context are large enough that it is aware of its own instructions, aware of the task, and capable of writing its own instructions to optimize solving the task in recursive iterations. [0]

By tuning the agent, it is possible to create trading strategies [1] and reverse engineer websites in order to create optimized JSON APIs using the websites internal private APIs. [2]

I'm having the hardest time communicating what is happening so next I'm going to try to explain it using data visualizations so people can visualize it in action.

[0] https://github.com/adam-s/agent-tuning

[1] https://github.com/adam-s/alphadidactic

[2] https://github.com/adam-s/intercept?tab=readme-ov-file#how-i...

Working on Fronteer, a project management app that (1) integrates messaging more cohesively with tasks and (2) better supports external collaborators - think agency clients, customers, etc.

Some of the biggest pain points we’ve seen is chat being separate from a solid task manager, and the pain of collaborating with people outside your own org.

We’re currently in private beta and hope to open it up to the general public soon!

https://fronteer.app

My wife has wanted a security system for a while. The turnkey cloud solutions freak me out. I've done some home automation with home aisstant before, and omg that was configuration slog. But with Claude..... It becomes fun.

Greetings from Munich. I’m building Joy, a CLI for product management. Your backlog is plain text in your git repo. joy add "fix the login bug", done. AI works through the same workflow as humans: identities, capabilities, cost budgets, every action in the git log. Still early. I use Joy to build Joy. Joy docs: https://joyint.com/en/joy/docs Ecosystem and trust model: https://joyint.com/en/docs/architecture Feedback welcome.

I'm building a browser for designers: https://matry.design/

Making rent as an open source developer.

Shamelessly trying to attract new monthly sponsors and people willing to buy me the occasional pizza with my crap HTML skills.

https://brynet.ca/wallofpizza.html

Outside of the day job (PM at an enterprise SaaS company), I've been building an AI-native CLI for Todoist [1]. Started to solve a personal problem, automating action item extraction from my Obsidian notes, but it's become something bigger. The CLI treats both humans and AI agents as first-class users: TTY-aware output, a schema command for agent discovery, idempotent operations, that kind of thing.

It's been a great excuse to get back to my roots as an engineer and lean into some of the newnew with Claude Code. Learning a ton, having a blast, and also enabling being (marginally) more productive with my actual work day to day.

[1] https://github.com/craigmccaskill/todoist-cli/

https://openscout.app - a local first communication tool, for agent to agent communication and user to agent communication too

I've got a bunch of irons in the fire at the moment, most leveraging or built with agentic coding tools; my harness of choice these days is pi+codex.

- An internal apps platform built with bun, pg-boss, and railway

- A smart music setlist manager that downloads chord charts, creates spotify playlists, and automatically drafts emails with attachments and practice schedules

- A recruiting intelligence platform called Spotter that I built in a weekend[0]

- A voice-agent for a client in the banking sector, implementing deterministic workflows using openai realtime voice + finite state machines[1]

[0] https://www.youtube.com/watch?v=AOedMSddGDg

[1] https://blog.davemo.com/posts/2026-02-14-deterministic-core-...

A complete guide on how to travel or live by van in Japan. Additionally trying to turn my passion into a revenue by offering tourists custom handcrafted plans for them to travel.

This is a fun side project as I learn great with email communication, culture differences (as a dev)

https://www.campinjapan.com/

https://github.com/thisisharsh7/modron-discord-bot

I am managing a discord community with over 1k+ members I found some people would regularly put spam links or message on all the channels and this been repetitive it's just take time deleting them one by one or reposting them into the specific channel. So I build a discord bot that would make this lot easier it catches the spam message post them into actual channel and also delete spam links. It's open source and easy to setup.

I am working on a system built around the OpenAI Responses API WebSocket mode as performance is something that interests me.

Its like a microservices architecture with NATS JetStream coordinating stuff. I want to keep the worker core as clean as possible, just managing open sockets, threads and continuation.

Document querying is something I am interested in also. This system allows me to pin a document to a socket as a subagent, which is then called upon.

I have hit alot of slip ups along the way, such as infinite loops trying to call OpenAI API, etc ...

Example usage: 10 documents on warm sockets on GPT 5.4 nano. Then the main thread can call out to those other sockets to query the documents in parallel. It allows alot of possibilities : cheaper models for cheaper tasks, input caching and lower latency.

There is also a frontend

Alot of information is in here, just thoughts, designs etc: https://github.com/SamSam12121212/ExplorerPRO/tree/main/docs

Too many things

- Tool to auto create dashboards from csv/json files or rest api ( https://EasyAnalytica.com )

- Tool to preview, annotate and share html snippets ( https://easyanalytica.com/tools/html-playground/ )

- Creating agent to edit files with smaller model(<1B) not yet released.

-Prompt assember to create prompts/templates/context and easily share between ai to be released this week.

I've been building an HLS streaming engine with Elixir. It takes care of asset segmentation, transcoding, and streaming. It supports regular VOD playout, as well as live streaming by dynamically building HLS playlists from a variety of sources, including transcoded VOD assets and other HLS livestreams. It has a basic scheduling system and I'm integrating a lua engine to allow dynamic scheduling using user-provided scripts.

I'm hoping to continue extending it until it can act as a full internet TV delivery stack like Pluto or Roku TV. It still needs to be behind a CDN for efficient delivery but basically any CDN would work.

Hey Team, working on a project that makes it easier to track time on Mac.

- There's a desktop app tracking the title bar and time you spend in each app. - You can use this 100% free, or sync this back to https://heygopher.ai to match the time up with your active projects. - if you use HeyGopher you can manage your time, team, projects, quotes and invoices.

This pairs pretty well with my normal project https://goodsign.io which is a Docusign alternative that is pay as you go. No subscription.

Playing with an idea of a next-gen self-hosted media server software, with rust, svelte and all the goodies.

But at my current knowledge and practical work, its like giving a chimpanzee a nuclear reactor schematic. But it's a passion project idea of mine, I really want it to become real one day. Personally, I feel like something much better can be made than current solutions.

I made Claude build me a web app to come up with anagrams: https://github.com/egeozcan/anagramci

I'm now having immense fun trying to come up with anagrams to whole sentences in Turkish.

I guess you could even automate finding anagrams (there are even web sites which allow you to do so), but Turkish agglutination makes it so much fun, and you can make really creative ones manually.

Once upon a time I even had made a tumblr to share what I found: https://sacmanagram.tumblr.com/ (also Turkish).

basically IT work. trying to "refactor" my home network, from wiring to the VLANs. created quite a few VLANs with plans for the future that I no longer remember and probably don't need anymore. and the wiring is very much spaghetti.

I'm working on my Open Source speaking clock (mostly for myself):

https://github.com/jcubic/speaking-clock

It uses local AI models for the voice.

Trying out games posted to HN so i can add them to https://hn-games.marcolabarile.me/

Testing out some ideas to automate data entry workflows from an italian powerlifting federation (FIPL) to OPL https://www.openpowerlifting.org/

I am building ExamineIP - Free network security toolkit

https://tools.examineip.com

Collection of 15 diagnostic tools (VPN leak test, DNS checker, port scanner, etc.) built after a WiFi security incident. All client-side, no data collection.

Feedback welcome!

I've been working on https://game-pick.eu , a website for friends to easily decide on games to play together. It is voting-based and can show who has which game in their library to see who would yet have to buy it. I'm planning on adding features for finding new friends to play with also. It's my first real web project, so I'm excited how it will go.

Working on implementing the web both auth standard and a take on federated and out-of-band agent bot validation.

https://github.com/calvernaz/wba

Cooperation Cube (https://cooperationcube.com/) — A strategic 4-player memory/semi-cooperative board game I designed, played on a rotating 3D cube. Just added a daily puzzle (https://cooperationcube.com/daily) you can play without signing up. Place sticks, complete patterns, and try to beat the day's challenge.

Live Kaiwa (https://livekaiwa.com/) — A real-time Japanese conversation assistant. It listens, transcribes, translates, and suggests responses so you can follow along in conversations you'd otherwise get lost in. I built it because I live in Japan and needed something for the situations where missing a nuance actually matters — PTA meetings, bank appointments, neighborhood councils.

I recently rebuilt my homelab after moving countries, and in the process updated Proxmox to v9.1.6. Been playing with centralizing my databases into their own LXCs rather than creating an individual one for each application.

When I started doing this, I also decided to try Proxmox's new OCI compatibility, which seems to be working well so far, so I am removing all my Docker VMs and recreating the containers directly on my hypervisor.

I've recently found the best way to find an apartment to rent in Bangkok. It's the Facebook Groups. Tons of owners post their listings there.

So, I've built a scraper that scrapes posts from Facebook Groups and made those posts filterable/sortable.

Now I'm looking to launch the same thing for US cities. Their Facebook Groups have tons of posts around subleasing/looking for accommodations.

If you are interested, here's the site for Bangkok: https://bangkokprop.com

Nitor - a discord clone with a shared/federated Identity layer, but self-hosted "servers/guilds". Trust model is to trust the guild server (e.g., so private channels work as one would expect with moderation capabilities), but to enable E2E DMs and friend/presence systems via guild servers as relays. Rust, Iced, Iroh.

Glyphcraft - a Minecraft mod (imagine if Thaumcraft, Ars Nouveau, and Hex Casting were smashed together)

I'm working on a calorie & macro tracker called FitBee [1]. Tracking my food has been tremendously helpful in terms of improving my health, but it's always been a PITA. The focus of FitBee is food quality & speed. Tracking your food is something you have to do multiple times a day, so I tried to make it as frictionless as possible. The app is built 100% with Swift & SwiftUI.

[1] https://apps.apple.com/us/app/fitbee-calorie-macro-counter/i...

https://sauna-assistant.com - Sauna master in your pocket

Got fed up that startups and small companies having to pay for Enterprise level compliance and sustainability tools, to be considered as a supplier.

So built Sustalium (https://sustalium.com) which is designed to be easier and faster for micro-small-medium businesses to comply with majority of compliance & sustainability frameworks.

I recently built Cranki [0], a free little PWA that generates crosswords using your Anki flashcard lists. It's aimed at language learners (who find flashcards boring and crossword fun!).

To be honest I built it just for me and then decided it might be useful for others.

It's all local, no server, no database, etc. Mobile and desktop friendly.

[0] https://cranki.app

I've been learning more about game development by recreating Slay the Spire in Godot.

I am working on https://github.com/xi/xiio, a minimal async runtime for python. It is mostly feature complete with a fraction of the code of asyncio or trio. It is great fun to get into low level stuff and hopefully it helps me to better understand the finer details of async programming.