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HubSpot Developer Changelog

Breaking Change: HubL Function Limits for Marketing Emails


Beginning on May 28, 2025, we are enforcing the CMS HubL function limits for all customers using the following functions in their Marketing Emails, per our Software Products, Packaging, and Limits policies.

Affected HubL Functions:

  • blog_authors
  • blog_by_id
  • blog_popular_posts
  • blog_post_archive_url
  • blog_recent_author_posts
  • blog_recent_posts
  • blog_recent_tag_posts
  • blog_total_post_count
  • content_by_id
  • content_by_ids
  • cta
  • crm_associations
  • crm_object
  • crm_objects
  • crm_property_definition
  • crm_property_definitions
  • file_by_id
  • files_by_ids
  • hubdb_table
  • hubdb_table_row
  • menu
  • postal_location
  • topic_cluster_by_content_id

Please refer to the HubL Function Developer Documentation for upper limits on HubL function usage.

What's changing?

Starting May 28, 2025, enforcement will require adherence to a limit of 10 function invocations per each listed function per email, which is crucial to reducing the cost of goods sold (COGS), rendering lags, and addressing reliability issues.

What does this mean for developers?

This change impacts developers building modules using the affected functions listed above and automated emails leveraging those modules. New emails exceeding the HubL function limit will prompt an error notification in the Review Panel and will not be published. The number of modules exceeding the function limit must be reduced to publish. 

Please note that we will gradually roll out the warning in the Review Panel to ensure you are not exceeding this limit. However, once this limit is enforced in 90 days, the warning will return as an error and can be referenced under “Required fields.”

See the examples below of the UI warning/errors for new emails exceeding the function limit.

As Warning

As Error

For published emails, if an email uses more than 10 function invocations, it will be dropped for that email recipient. The web version will return a 500 error if the limit is exceeded.

Users need to adjust emails and modules, limiting the number of HubL function invocations to avoid disruptions or errors.

When is it happening?

The new HubL function limits will be enforced on all new and pre-existing emails starting on May 28, 2025.

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