The agnostic-astro package utilizes XElement under-the-hood in order to provide build-time Astro components. These build-time components will help your project get closer to realizing a mostly no client-side runtime…if you do it right, this should mean an all-green 100% Lighthouse performance score! Leverage the benefits of Islands architecture by sending mostly server built agnostic-astro components. Then, sprinkle client-hydrated ones only as needed.

Ensure you've installed and setup the AgnosticUI Astro integration which will import the required common.min.css onto your page:

npm i astro-agnosticui

Then add the integration to your astro.config.mjs (you may need to run Astro with experimental integrations flag astro dev --experimental-integrations):

import { defineConfig } from 'astro/config';
import agnosticAstro from 'astro-agnosticui';;
export default defineConfig({
  integrations: [agnosticAstro()]
});

Then you can import Astro Disclose component (agnostic-astro ships with the astro-agnosticui integration):

import AgDisclose from 'agnostic-astro/Disclose.astro';

Here's the agnostic-astro Disclose component in use:

<AgDisclose title="My Title" @click={(event, store) => store.copy = 'look, I'm updating some state!'} >
  Some content goes here. <span>HTML tags are fine too—it's just a slot ;-)</span>
</AgDisclose>