SvelteKit allows you to create more than just pages. We can also create API routes by adding a +server.js file that exports functions corresponding to HTTP methods: GET, PUT, POST, PATCH and DELETE.
This app fetches data from a /roll API route when you click the button. Create that route by adding a src/routes/roll/+server.js file:
src/routes/roll/+server
export function GET() {
const number = Math.floor(Math.random() * 6) + 1;
return new Response(number, {
headers: {
'Content-Type': 'application/json'
}
});
}Clicking the button now works.
Request handlers must return a Response object. Since it’s common to return JSON from an API route, SvelteKit provides a convenience function for generating these responses:
src/routes/roll/+server
import { json } from '@sveltejs/kit';
export function GET() {
const number = Math.floor(Math.random() * 6) + 1;
return new Response(number, {
headers: {
'Content-Type': 'application/json'
}
});
return json(number);
}previous next
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<script>
/** @type {number} */let number = $state();
async function roll() { const response = await fetch('/roll');number = await response.json();
}
</script>
<button onclick={roll}>Roll the dice</button>{#if number !== undefined} <p>You rolled a {number}</p>{/if}