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Entity Changes API

Discover the details of the Entity Changes API.


Users can retrieve a chronologically sorted history of changes to WorldCat Entity data. 

 Note: Included with OCLC Meridian Subscription.

To learn about OCLC APIs and get started with the Entity Changes API, see:

If you're ready to start using the Entity Changes API, the OCLC Developer Network can help you learn more. The OCLC Developer Network allows you to learn about OCLC APIsview OCLC API documentation, and participate in the OCLC APIs community.

Types of changes

The following types of changes can be retrieved:

History Table Changes API
Create entity value Create
Add, remove, or replace entity value Update

Context and standard URLs


Main code

GET v1/changes
    "context": [
    "summary": "Worldcat Entity - Changes",
    "type": "OrderedCollection",
    "id": "",
    "first": {
        "type": "OrderedCollectionPage",
        "id": ""
    "last": {
        "type": "OrderedCollectionPage",
        "id": ""
    "totalItems": (total number of changed items)

Pages code

GET v1/changes/pages/{pageNumber}

Page1 is first page of changes in Wordcat Entities and Last page is most recent changes.

    "type": "Add, Remove, Create, Replace",
            "published": "2024-04-12T08:31:31.514Z",
            "object": {
                "id": "E39QJKdVFFTCvc69T8GmRRt4gJ",
                "type": "ENTITY_PROPERTY",
                "updated": "2024-04-12T08:31:31.514Z"