Cloud Function for ChicagoRoboto talk.

function.js

'use strict';

process.env.DEBUG = 'actions-on-google:*';
const Assistant = require('actions-on-google').ApiAiAssistant;

exports.myAction = (req, res) => {
  const assistant = new Assistant({request: req, response: res});
  console.log('Request headers: ' + JSON.stringify(req.headers));
  console.log('Request body: ' + JSON.stringify(req.body));

  // Fulfill action business logic
  function responseHandler (assistant) {
    // Complete your fulfillment logic and send a response
    assistant.ask('Im sorry to hear that your ' + assistant.getArgument('body-parts') + ' hurts. Does anything else hurt?', ['I didnt hear you', 'What else is causing you pain', 'I guess this concludes our consultation']);
  }

  const actionMap = new Map();
  actionMap.set('describe-symptoms', responseHandler);

  assistant.handleRequest(actionMap);
};

Learn more about the ApiAiAssistant class here https://developers.google.com/actions/reference/ApiAiAssistant

The webhook request/response format is described here https://developers.google.com/actions/reference/webhook-format