Sorry for the delayed response - was out on vacation.
I agree that most JAX-RS implementations have a type-safe client, and CXF (and possibly RestEasy?) already implement the MP Rest Client 1.0 APIs - so it would be a good idea to standardize the APIs in JAX-RS v.Next.
Some general thoughts:
* I would like to see the type-safe clients built out of ClientBuilder (rather than MP's RestClientBuilder) - we might need to "condense" the build method to include the base URI, but otherwise a client could be generated like:
MyClient clientProxy = ClientBuilder.newBuilder().build(baseURI, MyClient.class);
* ResponseExceptionMappers - I think this is a great value-add for rest clients - it adds to the type-safety since responses could be mapped to checked exceptions which might make more sense to app developers.
* CDI/MP Config support - This might be tricky, but is one of the nicest (IMO) features of MP Rest Client. This allows users to simply inject a rest client, avoiding the builder altogether. The trick is that it would require a dependency on CDI and MP Config (IIUC, the MP Config APIs are also getting moved to JakartaEE, so maybe this isn't a huge problem).
As for next steps, I could attempt to draft up a pull request that pulls in the MP Rest Client APIs into the javax.ws.rs.client.ClientBuilder class. I probably won't have anything to review very soon though - aside from the porting work, I will also need to check on any IP issues.
Thanks for bringing this up - I'm looking forward to contributing on this,