Amazon API Gateway added support for WebSockets in December, 2018. The original launch announcement includes a demo app that relays messages between clients.

This Android app provides the ability to read and write messages to that WebSocket endpoint, hosted in Amazon API Gateway.

To use it:

1. Deploy the Simple WebSockets Chat App.
2. Copy the WSS URL that is created above. It should look something like wss://YOUR_APP_ID.execute-api.YOUR_REGION.amazonaws.com/YOUR_STAGE. Set it as the value of websocket_url in app/src/main/res/values/strings.xml.
3. Import this Project into Android Studio
4. Build and Deploy

Try sending a message to API Gateway with wscat:

wscat -c <your_url>
{"action": "sendmessage", "data": "Hello from the other side."}

Check what happens on the app. You should see the message there.

You can click the "send message" button in the app to send a message the listener, too.

Two version of the app are provided:

1. One using Ktor, and
2. One using OkHttp