You can just push the leads from Clay to Bison with the “Update or Create” API call:
subdomain.your_link.com/api/reference#tag/leads/post/api/leads/create-or-update/multiple
A note for Clay is that it works with single endpoint API calls. So the “multiple” in this API call needs to be replaced with the email column from Clay as in the image below.
The upload will be scanned by Bison and it will check if the email already exists in Leads. If it does, it will update other info that is pushed by Clay. If it doesn’t exist, it will make a new Lead.