In Lambda, if you want to send a message to a WebSocket, you have to supply a HTTPS endpoint for the API Gateway control interface. However there appears to be no way to obtain this URL when the WebSocket is created via CDK,

Use Case

I want to create a WebSocket, and have a Lambda function send messages to connected clients in response to non-WebSocket events (e.g. SQS message arrival). This means I can't extract the WebSocket control address from the Lambda event object as it is not a WebSocket message that has triggered the function. Instead I must pass the WebSocket control URL in via some other method such as an environment variable.

Proposed Solution

There is already a WebSocketApi.apiEndpoint property for the WebSocket itself (minus the stage) so I guess it would work better in WebSocketStage having a property like .controlEndpoint.

So far I have worked around the issue by (in CDK) using a constructed string like this:

`https://${webSocketApi.apiId}.execute-api.${this.region}.amazonaws.com/${webSocketStage.stageName}`

But it would be nicer if this was provided by the library.

Other

• 👋 I may be able to implement this feature request
• ⚠️ This feature might incur a breaking change

This is a 🚀 Feature Request