HubSpot is introducing a new limit on the number of IDs that can be supplied to the Batch Read endpoint for (/{fromObjectType}/{toObjectType}/batch/read) both the v3 and v4 public Associations API. 

Effective February 10th, 2025, any batch read requests submitted to the Associations API may not exceed 1000 IDs per request body. This change applies to all subscription tiers and impacts processes or integrations using the Batch Read functionality.

What's changing?

• New Limit: The Batch Read Associations API request body now supports a maximum of 1000 entries in the inputs field.

In the example above, contacts are the fromObjectType, and companies are the toObjectType. The id of the contact whose associated companies we want to retrieve and after can be used for pagination by specifying the pagination token returned in the paging section of the previous response.

• Larger requests that exceed this limit will be rejected with an error response. Previously, larger batches were accepted, but this change is necessary to maintain API performance and efficiency.

What does this mean for developers?

This update affects any integrations or processes that submit batch reads to the Associations API with more than 1000 IDs at a time. Developers must update their code to ensure the batch size remains within the new limit. Requests exceeding 1000 IDs will result in a failed API call, which could disrupt existing workflows and integrations if not addressed.

Instructions to avoid breakage:

• Update existing processes to split batch read requests into smaller batches, ensuring that no more than 1000 IDs are submitted per request.
• Review your API integrations to confirm compliance with the new limit.
• If necessary, implement a loop to process multiple batches sequentially. This will ensure efficient handling of larger datasets while adhering to the 1000 id limit.

When is it happening?

A new limit for the Associations API's Batch Read feature will be enforced on February 10th, 2025. The limit will gradually decrease to 1000 over 30 days after February 10th, aiming to minimize inconvenience for users with more than 1000 IDs per request.

Important Note: 
The maximum number of IDs allowed in a single Batch Read request body will be increased from 100 to 1,000. Initially, we intended to apply a limit of 100, but to accommodate our customers better, we are increasing this limit to 1000.

Questions or comments? Join the developer forums for a peer-to-peer discussion.