the following RestClient does not propogate incoming headers:

    @RegisterRestClient(baseUri = "http://localhost:8180/accounts")
    @RegisterClientHeaders
    public interface AccountClient extends AccountResource { }

when overriding the Accountresource.getAccount() method, it does:

    @Override
    @GET
    @Produces(value = {MediaType.APPLICATION_JSON})
    @Path(value = "{id}")
    public Response getAccount(@PathParam(value = "id") Long accountId);

I assume the cause is in ClientHeadersRequestFilter.java. The method is not declared in the actual rest-client interface.

A possible solution could be a new static helper method:
ClientRequestContextUtils.getDeclaring(ClientRequestContext requestContext);