Setting up your Proxy
If it’s your first time using Balancer, you’ll need to approve a proxy contract. Each smart contract that moves your tokens requires you to unlock those tokens. Since each Balancer Pool is a different smart contract, interacting with them in the absence of a proxy contract would result in constantly unlocking the same tokens. The proxy contract acts as an approval layer that interacts with all the Balancer pools for you so that when a token is unlocked once, you have it unlocked for every pool.