# Ch04-Gateway-Protocol-and-Type-System

- [4.1 Protocol Design Philosophy](/en/ch04-gateway-protocol-and-type-system/4.1-protocol-design-philosophy.md)
- [4.2 TypeBox Type Schema](/en/ch04-gateway-protocol-and-type-system/4.2-typebox-type-schema.md)
- [4.3 Core Methods and Events](/en/ch04-gateway-protocol-and-type-system/4.3-core-methods-and-events.md)
- [4.4 Authentication and Authorization](/en/ch04-gateway-protocol-and-type-system/4.4-authentication-and-authorization.md)