Breaking Change for v3 Lists API Beta

[dennisedson]

The v3 Lists API beta currently accepts both integers and strings for the ID of public folders used for list segmentation and returns the ID as an integer. We will be updating the IDs to use only strings in order to conform to the HubSpot specifications.  This will go into effect on April 28th, 2025

What’s Changing

Currently, you can format a public folder ID as either an integer (INT) or a STRING in your request body.  Going forward, only strings will be accepted.  Furthermore, when getting a response, you should expect to see a string rather than an integer.  

Example JSON body of a POST request:

{
"parentFolderId": "139565122",
"name": "Folder of Doom"
}

Example JSON body of a response:

{
   "folder": {
       "name": "Folder of Doom",
       "id": "139410347",
       "parentFolderId": "139565122",
       "childLists": [],
       "createdAt": "2025-02-12T19:36:54.021Z",
       "updatedAt": "2025-02-12T19:36:54.021Z",
       "updatedContentsAt": "2025-02-12T19:36:54.021Z",
       "userId": 11176268,
       "childNodes": []
   }
}

 

When is it happening?

This change goes into effect on April 28th, 2025.