Client library providing WAMP on Java 8 (Netty) and Android, plus (secure) WebSocket for Android. The WebSocket layer is using a callback-based user API, and is specifically written for Android. Eg it does not run any network stuff on the main (UI) thread. The WAMP layer is using Java 8 CompletableFuture for WAMP actions (call, register, publish, and subscribe) and the Observer pattern for WAMP session, subscription and registration lifecycle events. The library is MIT licensed, maintained by the Crossbar.io Project, tested using the AutobahnTestsuite and published as a JAR to Maven and as a Docker toolchain image to Dockerhub.