fix: Remove StrEnum due to versioning

Author: vincent0426

src/mcp/server/elicitation.py

@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 import types
-from enum import Enum, StrEnum
+from enum import Enum
 from typing import Generic, Literal, TypeVar, Union, get_args, get_origin
 
 from pydantic import BaseModel
@@ -38,7 +38,7 @@ class CancelledElicitation(BaseModel):
 
 
 # Primitive types allowed in elicitation schemas
-_ELICITATION_PRIMITIVE_TYPES = (str, int, float, bool, StrEnum)
+_ELICITATION_PRIMITIVE_TYPES = (str, int, float, bool, Enum)
 
 
 def _validate_elicitation_schema(schema: type[BaseModel]) -> None:

tests/server/fastmcp/test_elicitation.py

@@ -2,7 +2,7 @@
 Test the elicitation feature using stdio transport.
 """
 
-from enum import StrEnum
+from enum import Enum
 from typing import Any
 
 import pytest
@@ -144,7 +144,7 @@ async def elicitation_callback(context: RequestContext[ClientSession, None], par
             assert field_name in result.content[0].text
 
     # Test valid Enum types (should not fail validation)
-    class Status(StrEnum):
+    class Status(str, Enum):
         ACTIVE = "active"
         INACTIVE = "inactive"