Is there a library for encoding/decoding arrays into/from bytedata for transactions?

Sixophrenia

There is a smart contract I want to make.
I want to give users the ability to submit multiple commands to my contract without having to do multiple transactions.

I know that everything is purely byte data. So I wanted to know if there was a library already created for handling things like this.
My goal is to handle 1 to 1000. I know that gas prices increase with more computational demands.
I know that regular transactions cost 21k gas, and I know that ADDing costs 3gas. So 1000 commands bundled into the transaction would be around an additional 3000 gas, which isn't bad