Is 0x free?

Could you please clarify if the 0x protocol is free to use? I've heard about the potential it offers in decentralized exchange, but I'm wondering if there are any associated costs or fees for utilizing the 0x platform. Does the protocol itself charge any transaction fees, or are there additional costs incurred by using it for building decentralized applications? Understanding the financial implications is crucial for me in deciding whether to integrate 0x into my financial solutions. Thank you for clarifying.