Empty response from API

[ansgarS]

Hey there, I am using the latest cdk-nextjs construct and want to fetch from an API route. I am using the pages router and just added this API route:

This route is not doing much:

Problem: When I call it, I can see the log in the server just before the return (so it really executes it), but I just get an empty response:

Any idea what I am missing in the setup?