I put together this simple fetch JS notebook & CORS@glitch sandbox last year for getting some stats on published ObservableHQ notebooks & notebook authors:

https://observablehq.com/@randomfractals/fetch

https://glitch.com/edit/#!/observable-cors?path=README.md:1:0

Peruse, fork & remix at will! :)

Dev discuss them (CORS & js notebooks) here || on Twitter:

Other#dataPixy 🧚‍♂️ #jsNotebooks 📚 ...