Websocket server ingests audio from the web client (web and micrphone audio stream), transcribes the audio real time, and writes the transcription events to KDS.
Websocket server is an optional component of the main LCA sample solution. You can deploy this component by enabling WebSocketAudioInput parameter in the LCA main stack.
The cloudformation stack deploys the websocket server to ECS Fargate and creates an endpoint used by the web client. Check LCAWebsocketEndpoint in Outputs section of the cloudformation stack.
The websocket server can tested by streaming a call recording using a node client utility. Check utilities/websocket-client.