Couple of suggestions/questions from using Google sheets to put enter some data that changed manually via back office admin which we then showed in a website that was accessed by thousands.
1. Will I hit rate limits if I access this API often via say GET requests from a public facing site? (What we did was used Redis as an intermediate cache)
2. Let's say the data on the sheet is changed, is there a webhook to notify the change? (What we did incorrectly initially was to rely on polling for change detection. Which was a bad idea especially as we grew increasingly reliant on this. Instead, the better way to do this is to put an 'Update' button in the sheet which then triggers an API call to an intermediate server to bust the cache I mentioned in the previous point. This also initiated a new fetch of the sheet data. A more user-friendly/better UX way to do this would be to use the Appscript Sheet APIs sheet change event handlers which can be leveraged for this if you don't want to enforce an update button on users though I haven't used this myself. [1])
In your case, I guess the way to do 2 would be to ask users to clone a sheet that has this Appscript code embedded in it when they create a new sheet that must be served with your API. No sure if the UX of that is acceptable though.
Wish your product success.
[1] https://developers.google.com/apps-script/reference/script/s...