Uses TS interfaces to create a request and get a response from Lambdas

InvokeGetGreetingLambda.ts

import { Lambda } from 'aws-sdk'

import { GetGreetingRequest, GetGreetingResponse } from './GetGreetingLambda.ts';

(async () => {
  const lambda = new Lambda({
    apiVersion: '2015-03-31',
    region: 'us-east-1',
  });

  const request: GetGreetingRequest = { // TS checks the Request properties
    firstName: 'Arian',
    lastName: 'Acosta',
    isFormal: false,
  };

  const params = {
    FunctionName: "LAMBDA_ARN",
    Payload: JSON.stringify(request),
  };

  const { Payload } = await lambda.invoke(params).promise();
  // Asserting the parsed object as GetGreetingResponse
  const response = JSON.parse(Payload as string) as GetGreetingResponse; 

  console.log(response.greeting); // TS autocompletes .greeting !
})();