**To send data to a WebSocket connection** The following ``post-to-connection`` example sends a message to a client that's connected to the specified WebSocket API. :: aws apigatewaymanagementapi post-to-connection \ --connection-id L0SM9cOFvHcCIhw= \ --data "Hello from API Gateway!" \ --endpoint-url https://aabbccddee.execute-api.us-west-2.amazonaws.com/prod This command produces no output. For more information, see `Use @connections commands in your backend service <https://docs.aws.amazon.com/apigateway/latest/developerguide/apigateway-how-to-call-websocket-api-connections.html>`__ in the *Amazon API Gateway Developer Guide*.