Hi @Blaise_d_Estais, welcome to the community 
Thanks for the mention @Federico_Stefanato 
My case is a little different from yours because sadly my doc have been over 125mb since his creation so i’ve never been able to use api with it.
My plan was to make some of the data in the doc available in a wordpress website, to create alternative and nearly limitless layouts and interfaces.
This for doc size and current api limitations evolved into “doc in coda.io as main client and export of some data into external website”
In my case i’ve a scheme based on the coda account of users (it’s like a multi-user app) that should in some ways be “connected” to a login in the external website, to give data to the right users.
So, my use case is a little bit “complicated” in this moment so i’ve post-poned it to a to be definied date, but if you plan on maybe some forms or something more “basic” it probably can be done, as Federico says tell us more about your case 
In this topic @oleg have highlighted that an intermediary passage was suggested to not make key public, but it’s an old post, maybe outdated
Know that if your doc is going to get bigger and bigger you’ll soon have to archive some part of it or trick the size improving columns type and others…
My actual consideration is anyway to not use trick or hack in production docs, to not be forced to re-adapt them at every coda’s update…
If it is like a “personal” project or a small website/mini app, with limited growth, it can be funny to have it on coda, if you do please share your impressions on the process you followed here
There are probably much more hacky users here that have tried something, let’s wait a bit