External API v2.0.0 - Support for content negotiation
The External API implementation uses the JAX-RS @Produces annotations to implement versioning. There is also some logic that analyzes the accept request header to determine the content-type of the response.
Currently, the External API does not support content negotiation. Not clear whether support for content negotiation is desirable or needed, but we could at least think about it and mention it in the specification.