Posted by bashtian 19 hours ago
I always had the problem that building HTML pages is really simple now, but trying to save data required hosting it somewhere, and sharing it afterwards was not easy. Over the last few months, I've been building an app called Capsule (it’s also the file extension name) written in Rust with Tauri 2.0 that allows packing an HTML app and its data into a single SQLite file.
The HTML file and any related assets are directly embedded in the database. User data can either be saved as a localStorage key/value store or via a MongoDB-inspired collections API as documents, saved in a table in the file. You can also save other assets, like PDF files or images, directly in the database to keep different documents together. All data can be easily exported to CSV or JSON if needed.
Privacy and security were a big priority for me, so documents cannot do anything out of the box. They don’t have direct access to the file system and they require permission to access the internet. The permission model is still something I’m working to improve. Capsule documents can also use local or remote AI models for document specific AI features.
One downside with this approach is that multiple people working on it will create different copies. To make it possible to merge different copies of the same file, each data entry has a unique UUID and timestamp.
I’m planning to open up the file format specification for the 1.0 version of the app so other apps can read or write Capsule files.
You can try it out in the web preview at https://withcapsule.app/preview with pre-built templates or use any AI provider of your choice to create a custom, Capsule-optimized app by using the following prompt:
"Please read the app wizard instructions at https://withcapsule.app/prompt.txt and help me design an app.“
I’m still working on the file format but there are migrations for each new version, so data should never be lost when using newer versions of the app in the future. Please let me know if you have any ideas or use cases where this might make sense or does not work.
PWA : Probably Web Again
Isn't html/css a better distribution mechanism as most computers already have the tech to run them?
Hence 200MB applications that are complete copies of the Chromium browser to run under 1MB of actual web code.
I've experienced the same limits building small tools for myself and friends that I wanted to contain in a single HTML file without external dependencies... but I understand why the same project without these restrictions could easily become malware, and ones that could be easily propagated.
However, every browser will let you download a new version of the HTML file and save it over the old one - yes, even from a local HTML file:
const blob = new Blob(['<!DOCTYPE html>\n' +
document.documentElement.outerHTML],
{ type: 'text/html' });
const a = document.createElement('a');
a.href = URL.createObjectURL(blob);
a.download = 'mypage.html';
a.click();
Saw it on HN a few weeks back
But I'm missing a few relevant features:
1. syncing data and apps (capsules) between my devices. not necessarily over a single SaaS, but maybe p2p or some existing service
2. I think data and apps should be separated, I might want to share an app with someone else without sharing the data
3. Apps should support updates, install the same app again and just replace the code for the existing app, but keep the data. Also share updates either as a file or publish apps to a repo (just a folder of files on a public http server or github repo)
Both keeping data in sync between devices and providing offline capabilities is hard, I know.
But there is something compelling in the idea - there is need for an interactive smart document format that you can share around easily. Kind of like a next gen markdown derivative cross with jupyter notebook where you bundle data, live parametric visualizations, code, audio, video, asciicinema like playback, comments, metadata, file artifacts etc
How would I know if I need this, vs something else?
I don't know about the stability/market value of this if you intend to turn this into something that attempts to make money, however. Said friend is currently using stuff like Gemini to generate HTML mini-apps as well; while he's not storing anything in databases, he's able to generate receipts and other things for essentially free.
I'm having Lotus Notes flashbacks.
This capsule thing seems to store the design itself within the database, which is odd to me. I guess I don't get it at 100%.