With API v3.1 you are able to manage all businesses that the authenticated user can access.
For users who have access to multiple businesses, the
X-Business header must be set if the request is for a business other than the lead business. This ensures API requests are routed to the user selected business.
For convenience, you no longer need to specify the
X-Business header, as API requests are automatically routed to the user’s lead business. To obtain their lead business, you can now call
Find out more about that in our Key Concept Best Practices.