Object of type User is not JSON serializable

[sysdagenaim]

Deployment Type

Self-hosted

NetBox Version

v3.7.6

Python Version

3.12

Steps to Reproduce

I created a custom_field for device roles content type named "created_by" .
It accepts Users > User as object type.
After I have created a permission with {"custom_field_data__created_by": "$user"} as constraint, I get 'Object of type User is not JSON serializable' when I try to either change or delete a device role created by myself. Putting my user id instead of "$user" works as expected.

Expected Behavior

Constraint with {"custom_field_data__created_by": "$user"} should recognize the User token

Observed Behavior

The user token "$user" is not recognized and I get 'Object of type User is not JSON serializable'

[sysdagenaim]

User token as defined in NetBox documentation returns an error : https://netboxlabs.com/docs/netbox/en/stable/administration/permissions/

[pkeroulas]

Our constraint scheme is based on Sites and Tenancy but it is incomplete as some Object Types are independent. User Token would help fill the gap but I confirm the behaviour described in the documentation is broken.