Topics

Novu offers a simple API providing an easy interface for triggering notifications to multiple subscribers at once. It is called Topics and allows the users to manage their bulk notifications without having to do complex loop implementations. A topic is identified by a custom key that is provided by the user. This custom key will be the identifier for the topic.

The topic key should be unique and can’t be changed once chosen. Novu also safe guards for key uniqueness behind the scenes.

Users can also assign a name to a topic. This name doesn’t need to be unique and it can be changed using the API. So far, it is for descriptive goals.

A topic would get assigned different subscribers that will receive a notification every time a notification is sent to the topic.

Common usecases

• Send to all users who have commented on a post.
• Send to all users who subscribed to task updates.
• Send an update to all tenant members
• Other use cases that require sending a notification to a group of subscribers around a specific structure

Create a topic

In order to be able to send a notification to a topic, first the user needs to create one. It can be done like this:

import { Novu } from "@novu/node";

const novu = new Novu("<NOVU_SECRET_KEY>");

const result = await novu.topics.create({
  key: "unique-topic-identifier",
  name: "descriptive-topic-name",
});

If successful this will return the internal Id generated by Novu and the topic key given by the user.

That topic key can be used to retrieve the whole Topic entity:

import { Novu } from "@novu/node";

const novu = new Novu("<NOVU_SECRET_KEY>");

const key = "unique-topic-identifier";

const result = await novu.topics.get(key);

Add subscribers to a topic

Adding subscribers to the topic is the main usecase of topic. A topic is like a group of subscribers. A notification can be sent to all subscribers of a topic at once

Before adding subscribers to a topic, it’s crucial to ensure that they are correctly identified in the Novu system. This identification is done using the identify method or API. When a subscriber is added to a topic, Novu uses the identification information to pick up the email or phone number associated with the subscriber.

import { Novu } from '@novu/node';

const novu = new Novu("<NOVU_SECRET_KEY>");

const topicKey = 'posts:comment:12345';

const response = await novu.topics.addSubscribers(topicKey, {
  subscribers: ['subscriber-id-1', 'subscriber-id-2', ...],
});

This call will return a response in the shape of:

{
    succeeded: ['subscriber-id-1', 'subscriber-id-2', ...],
    failed: {
      notFound: ['subscriber-id-1', 'subscriber-id-2', ...],
    },
}

The field succeeded will return the array of subscriber ids that have been correctly assigned to the topic. The field failed will show up only if there has been any subscriber that couldn’t been assigned to the topic. This probably will happen if there is any typo in the given subscriberId or if the given subscriberId doesn’t belong to the environment and the organization where the topic has been created.

One topic can have maximum 500K subscribers

Create topic on the fly

To facilitate flows we allow to create a topic on the fly when adding subscribers.

If the topic key used does not exist for the selected environment and organization, Novu will create a new topic with name Autogenerated-<TOPIC_KEY> and the subscribers will be assigned to this newly created topic. After that, that topic created on the fly can be managed in the same ways as the ones created in the normal way.

Trigger workflow to a topic

A workflow can be triggered to a single subscriber and an array of subscribers. While doing so, one need to send subscriberIds in to field. In case of trigger, we have already stored subscriberIds in a topic, so a topic key can be used to trigger a workflow. Workflow will be triggered to all subscribers in the topic.

const topicKey = "posts:comment:12345";

await novu.trigger("<WORKFLOW_TRIGGER_IDENTIFIER>", {
  to: [{ type: "Topic", topicKey: topicKey }],
  payload: {},
});

Exclude actor from topic trigger event

To exclude the actor responsible for the action of a triggered topic event, you must add the subscriberId of that actor when triggering that event.

const topicKey = "posts:comment:12345";

await novu.trigger("<WORKFLOW_TRIGGER_IDENTIFIER>", {
  to: [{ type: "Topic", topicKey: topicKey }],
  payload: {},
  actor: { subscriberId: "<SUBSCRIBER_ID_OF_ACTOR>" },
});

API

Fetch list of topics

Create a new topic

Add subscribers to a topic

Check if subscriber belongs to a topic

Remove subscribers from a topic

Fetch a topic by topic-key

Delete a topic

Rename a topic

Frequently Asked Questions

Does it mean that all subscribers of one topic have same preference

No, adding subscribers into topic does not change subscriber’s individual subscriber preference. Topic is mainly used to group subscribers and fan out workflow triggered notifications to all subscribers at once.