Integration with SvelteKit

With SvelteKit, you can run Elysia on server routes.

1. Create src/routes/[...slugs]/+server.ts.
2. Define an Elysia server.
3. Export a fallback function that calls app.handle.

// src/routes/[...slugs]/+server.ts
import { Elysia, t } from 'elysia';

const app = new Elysia()
  .get('/', 'hello SvelteKit')
  .post('/', ({ body }) => body, {
    body: t.Object({
        name: t.String()
    })
  })

interface WithRequest {
  request: Request
}

export const fallback = ({ request }: WithRequest) => app.handle(request)

You can treat the Elysia server as a normal SvelteKit server route.

Prefix

If you place an Elysia server not in the root directory of the app router, you need to annotate the prefix to the Elysia server.

For example, if you place the Elysia server in src/routes/api/[...slugs]/+server.ts, you need to annotate the prefix as /api.

// src/routes/api/[...slugs]/+server.ts
import { Elysia, t } from 'elysia';

const app = new Elysia({
  prefix: '/api'
})
  .get('/', () => 'hi')
  .post('/', ({ body }) => body, {
    body: t.Object({
      name: t.String()
    })
  })

type RequestHandler = (v: { request: Request }) => Response | Promise<Response>

export const fallback: RequestHandler = ({ request }) => app.handle(request)

This will ensure that Elysia routing will work properly in any location you place it.

Please refer to SvelteKit Routing for more information.