# Interfaces

- [IHats.sol](/for-developers/v1-protocol-spec/interfaces/ihats.sol.md)
- [IHatsIdUtilities.sol](/for-developers/v1-protocol-spec/interfaces/ihatsidutilities.sol.md)
- [IHatsEligibility.sol](/for-developers/v1-protocol-spec/interfaces/ihatseligibility.sol.md)
- [IHatsToggle.sol](/for-developers/v1-protocol-spec/interfaces/ihatstoggle.sol.md)