Customize Gateway Websocket Error Event

You can customize the error response in a websocket using api gateway's integration response. This allows you to define how errors are structured and what data they contain when they're sent to the frontend via websocket. You can configure the integration response to map specific error messages or attributes from Lambda or other backend services to the websocket error event payload.

1. Integration response mapping -> Integration response and configure mapping templates which can be used to define error attributes such as status code, error message, headers etc

https://docs.aws.amazon.com/apigateway/latest/developerguide/apigateway-websocket-api-integration-responses.html