KeyPair keyPair = KeyPairGenerator.getInstance("Ed25519").generateKeyPair(); BasicIdentity identity = BasicIdentity.fromKeyPair(keyPair); ReplicaTransport httpTransport = ReplicaOkHttpTransport.create(env.getProperty("ic.location")); final WebsocketTransport wsTransport = new JavaxWebsocketTransport(new URI(env.getProperty("ws.location")), httpTransport); WsAgent wsAgent = new WsAgent( Principal.fromString(env.getProperty("ic.canister")),	wsTransport, identity).setLocal(Boolean.parseBoolean(env.getProperty("local","false"))); wsAgent .addMessageHandler((output) -> {	try {	AppMessage result = IDLArgs.fromBytes(output).getArgs().get(0).getValue(new PojoDeserializer(), AppMessage.class);	LOG.info(result.text);	AppMessage response = new AppMessage();	response.text = "Pong";	response.timestamp = System.currentTimeMillis();	byte[] payload = WsAgent.encodeValue(response);	wsAgent.sendApplicationMessage(payload);	} catch (Exception e) {	LOG.error(e.getLocalizedMessage(),e);	} }); wsAgent.start(); // wait 100 seconds for messages from websocket Thread.sleep(100000); wsAgent.close(); 

<dependency> <groupId>org.ic4j</groupId> <artifactId>ic4j-websocket</artifactId> <version>0.7.0</version> </dependency> 

implementation 'org.ic4j:ic4j-websocket:0.7.0'