Domino-rest is a lib for generating rest clients from JaxRs compatible interfaces, and the generated clients can be used from both client side -browser- using GWT and on the server, the lib works in both GWT2 and GWT3/J2CL, the serialization and deserialization is based on domino-jackson, and service definition is based on JaxRs annotations, while code generation uses annotation processing APT.
Checkout the Quick start guide and visit our documentation in the wiki for more details.