Can i publish message to a pubsub topic from Firebase application directly?

[pallav jyoti bora]

Can i publish message to a pubsub topic from Firebase application directly?

[Olu]

I understand you are looking to use your Firebase application as the publisher application that creates and sends messages to a PubSub topic. At this point though, I am not exactly clear on what you mean by "directly" but of course, Sending messages to a PubSub topic depends on the type of Firebase application. I see no reason why it should not be possible. This documentation[1] shows how you could send messages to topics that multiple devices have opted for on Web/JavaScript. This Stackoverflow link[2] also discusses the possibility of using the Client library to send messages from your Firebase Cloud Functions to PubSub, I recommend you read the details shared on the page. 

[1]https://firebase.google.com/docs/cloud-messaging/js/topic-messaging

[2]https://stackoverflow.com/questions/48240813/how-to-publish-message-in-google-pub-sub-from-firebase-cloud-function