Clean up settings

src/fastmcp/server/auth/providers/bearer_env.py

@@ -1,15 +1,10 @@
-from enum import Enum
-
 from pydantic_settings import BaseSettings, SettingsConfigDict
 
 from fastmcp.server.auth.providers.bearer import BearerAuthProvider
 
 
-class NotSet(Enum):
-    sentinel = 0
-
-
-NOTSET = NotSet.sentinel
+class NotSet:
+    pass
 
 
 class EnvBearerAuthProviderSettings(BaseSettings):
@@ -35,11 +30,11 @@ class EnvBearerAuthProvider(BearerAuthProvider):
 
     def __init__(
         self,
-        public_key: str | None | NotSet = NOTSET,
-        jwks_uri: str | None | NotSet = NOTSET,
-        issuer: str | None | NotSet = NOTSET,
-        audience: str | None | NotSet = NOTSET,
-        required_scopes: list[str] | None | NotSet = NOTSET,
+        public_key: str | None | type[NotSet] = NotSet,
+        jwks_uri: str | None | type[NotSet] = NotSet,
+        issuer: str | None | type[NotSet] = NotSet,
+        audience: str | None | type[NotSet] = NotSet,
+        required_scopes: list[str] | None | type[NotSet] = NotSet,
     ):
         kwargs = {
             "public_key": public_key,
@@ -49,6 +44,6 @@ class EnvBearerAuthProvider(BearerAuthProvider):
             "required_scopes": required_scopes,
         }
         settings = EnvBearerAuthProviderSettings(
-            **{k: v for k, v in kwargs.items() if v is not NOTSET}
+            **{k: v for k, v in kwargs.items() if v is not NotSet}
         )
         super().__init__(**settings.model_dump())

src/fastmcp/server/server.py

@@ -187,7 +187,7 @@ class FastMCP(Generic[LifespanResultT]):
             lifespan=_lifespan_wrapper(self, lifespan),
         )
 
-        if auth is None and self.settings.auth_provider == "bearer_env":
+        if auth is None and self.settings.default_auth_provider == "bearer_env":
             auth = EnvBearerAuthProvider()
         self.auth = auth
 

src/fastmcp/settings.py

@@ -180,7 +180,23 @@ class ServerSettings(BaseSettings):
     )
 
     # Auth settings
-    auth_provider: Literal["bearer_env"] | None = None
+    default_auth_provider: Annotated[
+        Literal["bearer_env"] | None,
+        Field(
+            description=inspect.cleandoc(
+                """
+                Configure the authentication provider. This setting is intended only to
+                be used for remote confirugation of providers that fully support
+                environment variable configuration.
+
+                If None, no automatic configuration will take place.
+
+                This setting is *always* overriden by any auth provider passed to the
+                FastMCP constructor.
+                """
+            ),
+        ),
+    ] = None
 
 
 settings = Settings()