TransportProvider
A topic transport: what opens the broker a node's published streams, its commands to other contexts and their receipts go through. Wow's Kafka transport (kafka) is a provider as a community one, a Pulsar transport say, is: the host finds them on the classpath (ServiceLoader, from the module's META-INF/services/me.ahoo.wow.spi.transport.TransportProvider) and among the application's beans, a bean taking the place of a provider of its type on the classpath, as it finds a me.ahoo.wow.spi.store.StoreProvider.
A provider is stateless: open gives each configured transport its own TopicTransport, over the settings TransportConfig.options holds and the application's TransportConfig.resources.
Properties
Every setting of its own it reads from TransportConfig.options, each read through its option, for the host to bind and check (wow.<type>.<key>); a transport has no instances of its own, so it reads a ProviderOption.Scope.PER_STORE option as one of its type. The settings every topic transport has (TopicTransportOptions) are not listed again: TopicTransportOptions.of joins them.
What a transport of this type needs, in the words of a startup failure that says it is missing.