---
- custom_user_attributes: attributes = GET users/:user_id/custom_attributes
- custom_group_attributes: attributes = GET groups/:group_id/custom_attributes
- custom_project_attributes: attributes = GET projects/:project_id/custom_attributes
- custom_user_attribute: attribute = GET users/:user_id/custom_attributes/:attribute_key
- custom_group_attribute: attribute = GET groups/:group_id/custom_attributes/:attribute_key
- custom_project_attribute: attribute = GET projects/:project_id/custom_attributes/:attribute_key
- set_custom_user_attribute: attribute = PUT users/:user_id/custom_attributes/:attribute_key?
- set_custom_group_attribute: attribute = PUT groups/:group_id/custom_attributes/:attribute_key?
- set_custom_project_attribute: attribute = PUT projects/:project_id/custom_attributes/:attribute_key?
- delete_custom_user_attribute: DELETE users/:user_id/custom_attributes/:attribute_key
- delete_custom_group_attribute: DELETE groups/:group_id/custom_attributes/:attribute_key
- delete_custom_project_attribute: DELETE projects/:project_id/custom_attributes/:attribute_key