Update Property
contacts
Update Property
PUT
Update Property
Authorizations
Bearer authentication header of the form Bearer <token>, where <token> is your auth token.
Path Parameters
Body
application/json
No key and no type.
The key names the value inside contacts.custom_fields, so changing it orphans every value already stored. Changing the type would reinterpret them — "Gold" as a date, a multi-select collapsing to one value — with no way back. Both are a delete and a re-create, which at least makes the loss visible.