I have a working local environment using Laravel Valet to host a Laravel API and a Vite SPA which is authenticated using Laravel Sanctum. I have a Valet link for my Laravel API configured as api.mydomain.test which points to my API and a proxy for my SPA as app.mydomain.test => http://localhost:5173 (the Vite server). This setup works and I am able to have both applications running on the same domain through Valet.