Asynchronously assign a large number of Contacts to Clients in bulk.
Each item in the request body represents a single contact-to-client assignment, with the same parameters as the single Assign contact to client endpoint.

This endpoint initiates a background job to process your request, allowing you to assign up to 1000 records in a single operation.
Once complete, the job will provide a detailed report on the status of each assignment in CSV format.

If a contact is already assigned to the specified client, the assignment will be updated with the new settings.

This process is asynchronous; you can find a complete guide to the workflow in our Asynchronous Bulk Import API documentation.