I want to know if it is possible to use the web3 API with the flask framework instead of meteor or nodejs. if so how do I add it to my flask project?
I assume you are referring to writing python code to interact with Ethereum. If you want to integrate Ethereum with your python code, then you could go for the web3py package. It allows you to write interactions with the blockchain or specific smart contracts (assuming you have the ABI). It is basically a python implementation for web3.js.
Documentation for web3py can be found here: web3py docs
Documentation for web3.js can be found here: web3.js docs