Explored a lot of services from google like firebase, firestore, google assistant, dialogflow, cloudshell etc…. refreshed map api, found most services need payment account setting. Free is vanishing.

Connected my home IO devices through google assistant, IFTTT, adafruit. Could not find direct control to submit MQTT publish from IFTTT but through webhooks. Google Assistant can also call a php from my server to interact with MQTT (mosquitto) but asking money to do so.

Finally only way to do it free is using Google Assistant->IFTTT->myserver or Adafruit. Now “google switch on bedroom Light /Fan/TV/AC” etc blah blah is working fine. io.adafruit.com has restrictions so I used my own server to control the systems and its working fine.

Note: now IFTTT gone paid.