chore: Flip default in BaseCache

libs/checkpoint/langgraph/cache/base/__init__.py

@@ -15,7 +15,7 @@ FullKey = tuple[Namespace, str]
 class BaseCache(ABC, Generic[ValueT]):
     """Base class for a cache."""
 
-    serde: SerializerProtocol = JsonPlusSerializer(pickle_fallback=True)
+    serde: SerializerProtocol = JsonPlusSerializer(pickle_fallback=False)
 
     def __init__(self, *, serde: SerializerProtocol | None = None) -> None:
         """Initialize the cache with a serializer."""

libs/checkpoint/pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "langgraph-checkpoint"
-version = "3.0.1"
+version = "4.0.0"
 description = "Library with base interfaces for LangGraph checkpoint savers."
 authors = []
 requires-python = ">=3.10"