The transports that are available for an A2A server agent are determined by the dependencies that have been added to the application, e.g., see https://github.com/a2aproject/a2a-java/blob/main/README.md#server-transports.

When creating an AgentCard, the user must specify the primary endpoint for their A2A server agent and if the server agent supports multiple transports, these need to be specified as additional interfaces in the AgentCard.

It might be good to log some kind of warning if the AgentCard does not include all the transports available on the classpath.

Similarly, if an additional interface has been specified for a transport that isn't available on the classpath, it might be good to also log a warning in this case.