I'd like to know if the following is possible.
Swagger is almost what I need to document a Message based API. For instance for a Command Message I'd like to say "Command" instead of "Post", and instead of "path" I'd like to have the name of the Command.
The spec mentions that Vendor Extensions are possible using "x-" properties but I am 1) not finding any examples of how to do this and 2) not sure if the use of these properties would help me meet my goals.
Might anyone be able to point me to some resources that can help me move along?
Swagger is designed to document REST APIs which are based on HTTP verbs. You can't replace verbs or invent new ones.
Vendor extensions are there to allow adding additional information that the specification does not allow, but ultimately, it is still intended for REST APIs.
From what I gather, you're trying to describe something different.
We do welcome suggestions for additional roads for Swagger (that is, cover non-REST APIs), and in order to do that, I'd suggest opening an issue on the swagger-spec repository.