component: Platform>DevTools>Platform.
Use the protocol viewer for navigating the protocol.
TypeScript definitions for the protocol's types are available in 'types/protocol.d.ts'. Mappings from Commands and events to these types are available in either generated DomainApi style in types/protocol-proxy-api.d.ts or in simple name-to-type-interface style in types/protocol-mapping.d.ts.
Also, this repo is published as the devtools-protocol npm module.