server-env/server_environment/readme/USAGE.md

You can include a mixin in your model and configure the env-computed fields by an override of _server_env_fields.

class StorageBackend(models.Model):
    _name = "storage.backend"
    _inherit = ["storage.backend", "server.env.mixin"]

    @property
    def _server_env_fields(self):
        return {"directory_path": {}}

Read the documentation of the class and methods in models/server_env_mixin.py.

If you want to have a technical name to reference:

class StorageBackend(models.Model):
    _name = "storage.backend"
    _inherit = ["storage.backend", "server.env.techname.mixin", "server.env.mixin"]

    [...]