Hi everyone,
Those are my first days interacting with blockchain using infura. I could notice that there are two major NodeJs librairies (ethers and web3). I chose randomly ethers.
It seems to me that to be able to write on the blockchain I need to create myself a smart contract using solidity. But is it possible not to create myself a smart contract and only make API calls to infura which will then generate the smart contract ?
Thanks for your answers :visage_légèrement_souriant:
As far as I know, you need to create a smart contract the deploy it to blockchain(local, ropsten etc). once you get address contract, you can interact with that contract using address contract. maybe someone can explain how to generate a contract which is very usefull for developing smart contract 
That’s right, @Babarello check these two blog articles, they are a very good intro into these libs and basic web3 tasks:
Traian