Overcoming difficulties with JSON data loading (or another mistake)

[RandomFractals]

you might find this thread on cors useful too, to understand why things are set up the way they are for cors on observable and use my simple fetch.js notebook for testing when you enable it on your end for observable notebooks hitting your api

HTTPRequest Origin="null"

I think the main issue with the way observable sets up origin for code cell is that unlike the notebook itself, which has https://beta.observablehq.com origin, code cell frames are pinned to custom user static content. See origin request header generated from a fetch() cell call: [observable-fetch-headers] Therefore, even if you have control over the server hosting a data API you’d like others to use on observable, you can’t simply add beta.observable.hq.com to the ‘Access-Control-Allow-Orig…