Custom API in Framework Applications

[colsonLB]

Is it possible to create custom APIs in our Observable Framework applications? Since the applications are based on Node.js it seems like we should but I can't find any documentation on this (beyond parameterizing .md urls).

Essentially, I perform some initialization during the application startup and want to be able to access data from that initialization with API calls. When I Google or consult AI (seems like more "AI lies") I get that I need to create a folder structure src/routes/api and put .js files there which export POST/GET/etc. methods. Seems logical but it doesn't work. Both Copilot and ChatGPT indicate that this is possible and it seems reasonable but I can find no Observable documentation to confirm.

Also, using Express doesn't seem to work.

If anyone has accomlished this I would appreciate any insight. Thanks!