is there any way to let SvelteKit build only the code of one component.
E.g. lets say we have a component showing all participants of a conference. We would like to let SvelteKit generate only the
<head> and without other things within <body>)Thanks!
No, that is outside the scope of SvelteKit.
It's achievable with Svelte (no Kit) by using the Svelte compiler with a custom setup.
To generate the html code you'll need to compile the components with generate: 'ssr'.
That will generate the javascript you can run on the server to generate the HTML.
The compiler output is unbundled and doesn't run in a browser without bundling.
To get the "hydration-js" you'll need to compile the components again but with generate: 'dom', hydratable: true using a bundler with a svelte plugin.
Rich Harris, the creator of Svelte(Kit), was dogfooding Svelte(Kit) components on the NY Times site, which is not a Svelte app. So I think it is possible.
I haven't tried it myself, but Svelte Components as Web Components describes how to convert SvelteKit components into web components.
Using svelte components as web components is described in https://svelte.dev/docs#run-time-custom-element-api