import type {LexInputEvent, LexResponse, LexLambdaCb as LambdaCb} from 'flow-aws-lambda';
import type {Context as LambdaContext} from 'flow-aws-lambda';

function yourLambdaFunctionToFulfillLexIntent(event: LexInputEvent, context: LambdaContext, callback: LambdaCb) {
  if (... /* success */) {
    fulfillmentResponse("Your request has been fulfilled.", true);
  } else {
    fulfillmentResponse("Sorry, couldn't help you with that.", false);
  }
}

// just an example showing one possible LexResponse structure
function fulfillmentResponse(content, success): LexResponse {
  return {
    "dialogAction": {
      "type": "Close",
      "fulfillmentState": success ? "Fulfilled" : "Failed",
      "message" : {
        "contentType" : "PlainText",
        "content" : content
      }
    }
  }
}