About the Structure of Events

Wix APIs support event-driven integrations, allowing you to respond to changes such as create, update, and delete actions. How you handle events depends on the API you use:

• REST API: The REST API delivers events via webhooks.
• JavaScript SDK: The SDKs deliver events using event handlers in your code.

This article describes the structure of events for both REST webhooks and SDK event handlers.

REST webhook payloads

REST webhook payloads contain a data object with the following fields, encoded as a JWT:

Field	Description
eventType	The event type. For example: wix.contacts.v4.contact_merged.
instanceId	The app instance ID, which identifies the site where the event occurred.
data	Event data object as a JSON string containing fields specific to the event type. The structure and fields are specific to each webhook. Refer to each webhook's reference for the exact structure and fields.
identity	Identity object as a JSON string.

SDK event handlers

SDK event handlers pass an event object with the following fields:

Field	Description
metadata	An object containing event metadata, including eventType, instanceId, identity, and other information about the event. The structure and fields are specific to each event. Refer to the event's reference for the exact structure and fields.
entity	The state of the affected entity after the event occurs.
modifiedFields	The updated fields and their values before the event occurred. Included for some updated events.

Event data

In REST webhooks, the event data is in the data.data field. In SDK events, the event data is in the event.metadata field, except for entity data.

The content of the event data varies by event type, but generally includes the following:

• Entity data:
  • For created events, this is the newly created entity.
  • For updated events, this includes the entity after the update and sometimes the updated fields with their previous values.
  • For deleted events, this may include the deleted entity.
• Event context: Additional details about the event, such as when it occurred or the reason for the change.
• Action-specific data: For specific actions like publishing or sending, data relevant to that action.

Refer to the documentation for each event to see the exact structure and fields included in its data.

The modifiedFields object

Some updated events include a modifiedFields object. This object contains the values of fields that changed, as they were before the update. Use modifiedFields to compare old and new values or to track what changed.

The location of the modifiedFields object differs between REST webhooks and SDK events:

• REST webhook payloads: data.data.updatedEvent.modifiedFields
• SDK event handlers: event.modifiedFields

Identity

The identity information includes the type and ID of the identity that triggered the event:

Field name	Description
identityType	Identity type that triggered this event. Supported values: ANONYMOUS_VISITOR, MEMBER, WIX_USER, APP. See About Identities.
One of:
anonymousVisitorId	Site visitor ID.
memberId	Site member ID.
wixUserId	Wix user ID.
appId	App ID.

Legacy webhooks

Some legacy REST webhooks don't follow the standard structure described above. For example, the legacy Wix Stores Product Changed webhook returns only the fields that changed with their updated values, in a flat list rather than the full object structure.