> ## Documentation Index
> Fetch the complete documentation index at: https://docs.novu.co/llms.txt
> Use this file to discover all available pages before exploring further.

# Topic schema

> Reference the Novu topic schema used in API requests and responses. Review fields, data types, and object structure for this resource.

### Topic

Topic is a collection of subscribers that share a common interest. Subscriber can subscribe to multiple topics. When a subscriber is subscribed to a topic, they will receive notifications generated by workflows triggered to that topic.

| Field | Type | Description |
| - | - | - |
| `id` | `string` | The identifier of the topic |
| `key` | `string` | The unique key of the topic |
| `name` | `string` | The name of the topic |
| `data` | `object` | Optional flat custom data (string, number, boolean, or string\[] values). Maximum serialized size: 64KB. Returned on topic and topic-subscription API responses. |
| `createdAt` | `string` | The date the topic was created |
| `updatedAt` | `string` | The date the topic was last updated |

### TopicSubscription

TopicSubscription is a relationship between a subscriber and a topic. It is used to track which subscribers are subscribed to which topics and when they subscribed. `createdAt` is the date and time the subscription was created.

| Field | Type | Description |
| - | - | - |
| `id` | `string` | The internal ID generated by Novu for the subscription. Use this when referencing the subscription by its database ID. |
| `identifier` | `string` | The user-supplied key provided when creating the subscription. Use this to look up or manage a specific subscription within a topic. |
| `createdAt` | `string` | The date and time the subscription was created |
| `topic` | `TopicResponseDto` | Topic information |
| `subscriber` | `SubscriberDto` | Subscriber information |
| `contextKeys` | `string[]` | Context keys that scope this subscription (e.g., tenant:org-a, project:proj-123) |

### Subscriber

Subscriber is a user who can receive notifications. Read more about subscribers on [subscribers concept page](/platform/concepts/subscribers).

| Field | Type | Description |
| - | - | - |
| `id` | `string` | The internal ID generated by Novu for your subscriber. This ID does not match the `subscriberId` used in your queries. Refer to `subscriberId` for that identifier. |
| `firstName` | `string` | The first name of the subscriber. |
| `lastName` | `string` | The last name of the subscriber. |
| `email` | `string` | The email address of the subscriber. |
| `phone` | `string` | The phone number of the subscriber. |
| `avatar` | `string` | The URL of the subscriber's avatar image. |
| `locale` | `string` | The locale setting of the subscriber, indicating their preferred language or region. |
| `channels` | `ChannelSettingsDto[]` | An array of channel settings associated with the subscriber. |
| `topics` | `string[]` | An array of topics that the subscriber is subscribed to. |
| `isOnline` | `boolean` | Indicates whether the subscriber is currently online. |
| `lastOnlineAt` | `string` | The timestamp indicating when the subscriber was last online, in ISO 8601 format. |
| `v` | `number` | The version of the subscriber document. |
| `data` | `Record<string, unknown>` | Additional custom data for the subscriber |
| `timezone` | `string` | Timezone of the subscriber |
| `subscriberId` | `string` | The identifier used to create this subscriber, which typically corresponds to the user ID in your system. |
| `organizationId` | `string` | The unique identifier of the organization to which the subscriber belongs. |
| `environmentId` | `string` | The unique identifier of the environment associated with this subscriber. |
| `deleted` | `boolean` | Indicates whether the subscriber has been deleted. |
| `createdAt` | `string` | The timestamp indicating when the subscriber was created, in ISO 8601 format. |
| `updatedAt` | `string` | The timestamp indicating when the subscriber was last updated, in ISO 8601 format. |


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