New Add-on Attachment Parameter and Namespace Deprecation
Change effective on 14 February 2026
We are updating the Add-on Attachment resource in the Heroku Platform API. These changes provide more granular control over how add-ons are attached to apps while streamlining the API schema for future scalability.
New Parameter: namespace_config.
We have introduced a new parameter, namespace_config, to the add-on attachment resource. This parameter allows developers to define complex configuration structures for attachments, specifically aiding in scenarios where add-on resources (like Heroku Postgres credentials or Redis instances) need specific isolation levels or specialized routing within an application.
Deprecation: namespace Parameter
To simplify the API and encourage the use of the more robust namespace_config, the legacy namespace parameter is now deprecated. 30-Day Notice: The namespace parameter will remain supported until March 13, 2026. Action Required: After this date, requests using the namespace parameter will no longer be supported. We recommend all developers migrating to the namespace_config parameter immediately to avoid service interruptions.