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Leftiumon Show HN: Keyjump – a keyboard-first new tab for power-users

A goal of the site used to be to function without JS. (A progressively enhanced app) And it's a serverless app. So localStorage and DB were not options.

Leftiumon Show HN: Keyjump – a keyboard-first new tab for power-users

I've been making something similar: https://multi-launch.leftium.com

Special features:

- similar concept to Keyjump queries: the links change to search templates if the query input has a value

- it can launch multiple bookmarks/queries at once (the blue category buttons)

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The next version is based on the realization search bangs are bookmarks + search templates: https://zbang.leftium.com

- Unique feature: double-keypress is effectively keyboard shortcut that also works on mobile! (FF to toggle fullscreen, QQ to select first result...)

- Right now it's just a list of search bangs, but this list will be moved to a slash command

- Then the list will be replaced with your own bookmarks, sorted by "frecency," with favorites pinned to the top.

- Another tab will list your bookmark (search) history: a sort of "zero effort" journal. (I switched to Kagi, which lacks search history. And browser history is insufficient.)

- Another tab can contain your notes (like SimpleNote)

- I may even integrate dictation, so you don't even have to touch the keyboard (https://rift-transcription.vercel.app)

Leftiumon Show HN: Markdown Prism – A Non-Electron Markdown Editor for macOS

Very nice!

I've been using mdserve. A nice feature is a sidebar that lists all the MD files in a directory. I wish it could also list sub-directories.

The reason is because I organize related MD files in directories, with sub-directories. Folders without MD files should be filtered out.

Here is an example project with MD files in both reference and specs (and root) folders. Other folders should be filtered out: https://github.com/Leftium/rift-transcription

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The brew install did not work; the App source name is wrong: `Error: It seems the App source '/opt/homebrew/Caskroom/markdown-prism/0.2.0/Markdown Prism.app' is not there.`

Leftiumon Ask HN: Why is my Claude experience so bad? What am I doing wrong?

It seems to me you expect Claude to be able to one-shot your tool based on a single prompt. Potentially "vibe-coding" as in the sense: you don't know how to develop this yourself (perhaps you are not a software developer?)

While this may be possible, it likely requires a very detailed prompt and/or spec document.

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Here is an example of something I successfully built with Claude: https://rift-transcription.vercel.app

Apparently I have had over 150 chat sessions related to the research and development of this tool.

- First, we wrote a spec together: https://github.com/Leftium/rift-transcription/blob/main/spec...

- The spec broke down development into major phases. I reviewed detailed plans for each phase before Claude started. I often asked Claude to update these detailed plans before starting. And after implementation, I often had to have Claude fix bugs in the implementation.

- I tried to share the chat session where Claude got the first functional MVP working: https://opncd.ai/share/fXsPn1t1 (unfortunately the shared session is truncated)

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"AI mistakes you're probably making": https://youtu.be/Jcuig8vhmx4

I think the most relevant point is: AI is best for accelerating development tasks you could do on your own; not new tasks you don't know how to do.

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Finally: Cloudlflare builds OAuth with Claude and publishes all the prompts: https://hw.leftium.com/#/item/44159166

Leftiumon Show HN: TabChop a truly painless way to split a tab

Oh~ I missed "Shared items split cleanly" in the copy. And I didn't feel like creating a new account to check it out. Would be nice if you didn't have to sign up/login. (Maybe like how a shopping cart allows creating an account at checkout)

(And I initially thought "TabChop" would be a windows management tool: split windows...)

Leftiumon Show HN: TabChop a truly painless way to split a tab

In Korea (and probably other cultures) the whole group orders items together and shares. So the splitting math is a little different:

- Simplest: just divide total by N people

- Different subtotals for food, alcohol, and drinks

- The most complex is probably: food is split evenly, but individuals claim beverages. (And there are some cases where certain food items are also claimed.)

Usually one person is the "treasurer:" they pay the entire bill and make a chat room to finalize with other members (share a table of who owes what and maybe send payment requests)

Interestingly, KakaoTalk has a built-in feature to split bills in this manner. It's not intuitive to use, so a lot of people just do it manually.

Leftiumon Show HN: Pindrop – Mac-native dictation app built with Swift/WhisperKit

"You can’t use this version of the application “Pindrop” with this version of macOS."

- "Requires macOS 14+ (Sonoma) or later."

- Tried on macOS v15.7.3 (Sequoia)

Leftiumon Ask HN: Do you bother making state changes reversible?

There are forms of state that are reversible: essentially, you store read-only events instead of writing to existing state.

The main disadvantages are more complexity and performance issues.

Examples:

- Event sourcing: https://youtu.be/8JKjvY4etTY

- CRDT

- At the DB layer: https://www.datomic.com

- You can also do it at the code level (but this is more like keeping copies of the old state): https://immerjs.github.io/immer

Leftiumon Show HN: Coi – A language that compiles to WASM, beats React/Vue

Svelte used to have compile-time reactivity, but switched to runtime reactivity via signals: https://svelte.dev/blog/runes

I'm curious if Coi will also suffer from the drawbacks of compile-time reactivity. Or as its own language that doesn't have to "fit" into JS, can Coi side-step the disadvantages via syntax?

Runes allowed simpler Svelte syntax while making it more clear, consistent, flexible, and composable.

Support for signals may help in terms of interop with native browser JS and other frameworks: https://github.com/tc39/proposal-signals

Leftiumon Ask HN: What's a good format to submit CSV data for LLMs?

Instead of directly passing the CSV data to the LLM, have the LLM write a script that will read the CSV and output the trends. (Then it can run the script and report on the results.)

I wanted to figure out reasonable values for range of daily/hourly precipitation for https://weather-sense.leftium.com. Claude wrote a script to call the Open Meteo API to collect hourly stats for a few cities for an entire year (8000+ rows), then just reported the 80th, 90th, etc percentiles and recommended ranges.

Leftiumon Ask HN: Books to Learn Ruby/Rails?

Not sure if this would be helpful, but your question reminded me of this classic: https://poignant.guide

Context (the author): https://en.wikipedia.org/wiki/Why_the_lucky_stiff

Leftiumon Do people still need websites, or just a public page?

I think web sites are often a "feature" or means to an end. It may be better to focus on the benefits. (Like more sales/revenue. Reduced customer support. Etc.)

For example, I had a client who wanted me to build a web site that hosted her piano lessons. She was sure if only they were hosted somewhere, people would flock to it.

I tried to tell her what she really wanted was marketing and sales, which the web site could be a small part of. She insisted so we built the site anyway. I don't think it's ever gotten any sales...

Leftiumon Do people still need websites, or just a public page?

https://veneer.leftium.com is a similar project: a thin layer over Google sheets/forms:

- Adds markdown support

- Makes it prettier, especially on mobile

- Adds open graph social sharing image/title

Based on actual convention used by (dance) groups in Korea to use Google forms for event sign ups. It doesn't require changing their workflow: the original forms still work (as a fallback), they just need to share a different URL based on the form ID.

I've shown Veneer to several dance group organizers who use these Google forms on a regular basis. While two people have embraced the concept and registered their custom domains for their forms most people are surprisingly hesitant to use Veneer. Objections I've heard:

- Already have a workflow; don't want to learn something new

- Know how to program themselves, can make themselves if needed

- Already registered an unused domain, but have other plans for the site

- Prefer simple (even though I simplified: https://red.leftium.com)

Each Veneer page has a link to the original Google form and sheet. (Also a link to the full MIT-licensed source.) Here is the only one that is "in production:" https://viviblues.com

One advantage I've noticed for Tailwind:

- If you just paste an outerHTML from the dev tools, AI coding agents can immediately figure out what it will look like; debug styles; etc.

I personally preferred PicoCSS for a long time. Pico was nice, but it injected a lot of CSS var noise into the dev tools and I started fighting with the breakpoints.

More recently, I've been just doing handcrafted CSS with a bit of OpenProps.

Leftiumon Eulogy for Dark Sky, a data visualization masterpiece (2023)

Fair enough. I added a toggle button and removed decimal °C.

Weather uncertainty may make that extra precision less useful.

Leftiumon Eulogy for Dark Sky, a data visualization masterpiece (2023)

Thanks for the feedback. You helped make my app more readable (I went a little overboard on the gradients; I thought the gradients would help convey the sky condition):

- Now most gradients are disabled by default. (toggle here: https://weather-sense.leftium.com/wmo-codes)

- Also added shadow/glow to plot lines so they "pop out" more.

I'm not sure which parts you think are blue and teal. Open to suggestions for better colors! (There are only so many colors, and I like keeping the precipitation related colors all bluish.)

Leftiumon Eulogy for Dark Sky, a data visualization masterpiece (2023)

You mean you prefer C over F? Tapping any temperature will toggle between the two. (This always comes up, so the app should probably default to units based on the user's location: the default is F only if the app detects you're in the US)

- Toggling C/F also toggles the scale on the radar to km. Eventually, I will get around to adding a dedicated settings page.

- However, the app was designed so one could get a sense of the weather without numeric labels: temperature is a very relative experience, so use the spatial/color cues to compare yesterday, today, and forecast days.

- Notice now much more space C needs when toggling between C and F. F's 0 to 99 range fits the natural range of temperatures humans experience (weather, body temperature). Humans just don't experience anything beyond 50 degrees C. At the same time, a single delta C is too large for the precision human bodies can detect. (Humans need something closer to 0.5C precision, which is what 1 degree F is.)

- As as result C needs nearly twice as much horizontal space compared to F: due to going negative more often and needing an extra decimal for minimal precision required.

Leftiumon Eulogy for Dark Sky, a data visualization masterpiece (2023)

Perhaps I should add an option to disable gradients.

There's a screen shot showing what it used to look like before gradients: https://github.com/Leftium/weather-sense

Leftiumon Eulogy for Dark Sky, a data visualization masterpiece (2023)

> It removes a sense of artificial precision that doesn’t really exist because weather forecasts fundamentally have very high uncertainty and error bands.

So true.

Open Meteo supports 28 different WMO weather condition codes[1]. Most weather apps only support half as many. (Just "rain" instead of light/moderate/heavy rain.)

Showing all 28 is less helpful because of the noise. More useful just to show it might rain for a period of several hours vs oscillating between light rain and heavy rain. The light vs heavy precision wasn't worth it when there was high uncertainty whether it would even rain at all.

So https://weather-sense.leftium.com consolidates hours with similar weather conditions into a single segment by default. You can click on the weather icons at the left of the plots to toggle the original unconsolidated view.

[1]: https://weather-sense.leftium.com/wmo-codes

Leftiumon Eulogy for Dark Sky, a data visualization masterpiece (2023)

https://weather-sense.leftium.com shows both mm/hr and percentage chance.

I've noticed there is a correlation, but having both is useful:

- Often there is a percentage chance, but the mm/hr is 0. At these times, it could rain but will probably be very light.

- Less common, but sometimes there is 0% chance, but a non-zero mm/hr.

Leftiumon Eulogy for Dark Sky, a data visualization masterpiece (2023)

Yes, but currently only possible via url param:

- https://weather-sense.leftium.com/?n=nyc

n is short for "name" and uses the Open Meteo geocoding API[1].

[1]: https://open-meteo.com/en/docs/geocoding-api

Leftiumon Eulogy for Dark Sky, a data visualization masterpiece (2023)

On https://weather-sense.leftium.com the colored boxes in the legend at the top are actually checkboxes.

Toggle only the stats you're interested in! The toggle is persisted to localStorage.

I plan to add more stats, like wind speed and direction, but they will all be toggle-able.

Leftiumon Eulogy for Dark Sky, a data visualization masterpiece (2023)

I designed https://weather-sense.leftium.com to make it easier to visualize both the day and week.

Even without any text labels, you should be able to get a feel for what the weather is and how it will change:

- Hourly plots like Dark Sky, with everything (temperature, rain, AQI, weather conditions) in a single plot.

- The change in temperature visualized with both color and space. Space is obvious (higher -> hotter); color ranges from red for hottest to blue for coldest. All the visible plots share the same color-temperature mapping. So the gradient block to the left shows both the temperature range for that day as well as how it compares to other days.

- Finally, there is a weekly overview at the top.

Leftiumon Eulogy for Dark Sky, a data visualization masterpiece (2023)

https://weather-sense.leftium.com: just a web app, but you can add it to your home screen to access like an app[1]

[1]: https://polarhabits.com/mobile

Leftiumon Eulogy for Dark Sky, a data visualization masterpiece (2023)

https://weather-sense.leftium.com shows the past two days of weather, could be configured to show up to 90.

- The data is from https://open-meteo.com

- It would be trivial to connect the historical weather API (back to 1940): https://openmeteo.substack.com/p/processing-90-tb-historical...

Leftiumon Eulogy for Dark Sky, a data visualization masterpiece (2023)

You might also like https://weather-sense.leftium.com

Leftiumon Eulogy for Dark Sky, a data visualization masterpiece (2023)

Inspired by MerrySky: https://weather-sense.leftium.com

Some differences:

- Shows weather from yesterday for comparison

- All hourly plot trackers connected; not just the top one

- Includes AQI

- Sky color visualization (try scrubbing across dawn/dusk!)

- Non-precipitation colors approximate sky color (haziness)

- Temperature variation visualized both spatially and with colors

- Data source is Open Meteo

- Planned: 60 minutely forecast like https://openweathermap.org

Leftiumon Ask HN: What are you working on? (Jan 2026)

https://weather-sense.leftium.com

- The first half was all manually coded, no AI.

- Claude Opus 4.5 helped add several features I had been planning.

Some features were added on a whim because AI makes experimenting so cheap. Like the UI color gradients reflecting the color of the sky based on time of day.

Just needed to point Claude at https://hw.leftium.com/#/item/44846281. Then we worked together to tweak the palette colors and UX (like smoothly transitioning between colors, tweaking more vibrant sky colors)

Open source: https://github.com/Leftium/weather-sense

Leftiumon Show HN: My not-for-profit search engine with no ads, no AI, & all DDG bangs

I'm not sure if !cobalt would meet Kagi's guidelines for public bangs.

Eventually, zBang will execute bangs locally before falling back to a Kagi network call. It's open source: https://github.com/Leftium/zbang

I just remembered my other project can support cobalt. Just enter the youtube URL and press ENTER (or click the buttons): https://mm.leftium.com?p=C4S2BsFMAIF5oEQGED2AjAhuY0AikBbFBAK...

- The link above embeds the cobalt "launch plan" (config) in the URL, but it could also be added as one of the built-in plans like https://mm.leftium.com/svelte.

- Also open source (and very simple to deploy): https://github.com/Leftium/multi-launch

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But what's the difference between these two?:

1. Go to https://nilch.org and search for `!cobalt YOUTUBE URL`

2. Go to https://cobalt.meowing.de and search for the YOUTUBE URL

I think #2 is actually simpler for that person you are trying to help.

Leftiumon Show HN: My not-for-profit search engine with no ads, no AI, & all DDG bangs

(replying to dead reply downthread)

Kagi (custom) bangs[1] already supports `!cobalt <youtube video>`

I just added !cobalt to my custom bangs as `https://cobalt.meowing.de#%s`, and it works.

Kagi also accepts new public bangs: https://github.com/kagisearch/bangs#contribution-guidelines

Kagi bangs are free for everyone (a subscription is required for custom bangs and regular search).

- Example of how to use Kagi bangs without subscription: https://kagi.com/search?q=!chatgpt+TEST

- https://zbang.leftium.com/ uses Kagi bangs under the hood.

[1]: https://help.kagi.com/kagi/features/bangs.html#custom-bangs