The Toit cloud has it's own publish/subscribe technology that is inspired by Google's PubSub.
Data that is published by your IoT devices, is received by the Toit cloud, which then makes the data available for subscribing applications: being either a Toit application running on another IoT device, or a third-party application.
The Toit cloud makes use of subscriptions and topics to achieve this asynchronous communication mechanism.
Topic: A named resource to which messages are sent by publishers.
Subscription: A named resource representing the stream of messages from a single, specific topic, to be delivered to the subscribing application.
Message: The data that a publisher sends to a topic and is eventually delivered to subscribers.
Publisher: An application that creates and sends messages to one or several topics.
Subscriber: An application with a subscription to one or more topics to receive messages from it.
Acknowledgement: A signal sent by a subscriber to PubSub after it has received a message successfully. Acked messages are removed from the subscription's message queue.