Creates or updates a single user record, including associated attributes, subscriptions, and identifiers. If a user with the provided identifiers already exists, their information will be updated; otherwise, a new user will be created.
There is a limit of 100 of custom attributes that can be created. If intending to update an existing attribute, the name of the key must match the name of the existing attribute. If an existing attribute does not exist, a new attribute will be created with the given key as the name. Attributes with enumerated values must have a value that matches an existing enum value; new enum values will not be created. Attempting to pass custom attributes as an array or a map such as ["New York City] or {"favorite city": "Boston"} will result in a 400 error.
Default Rate Limit: 150 requests per second