feat: Integrate Valkey with LangGraph LLM Cache (#717)

Enables use of Valkey to cache LLM responses in LangGraph

Author: seaofawareness

libs/langgraph-checkpoint-aws/langgraph_checkpoint_aws/__init__.py

@@ -1,6 +1,6 @@
 """
 LangGraph Checkpoint AWS - A LangChain checkpointer implementation using
-Bedrock Session Management Service.
+Bedrock Session Management Service and Valkey.
 """
 
 from importlib.metadata import version
@@ -12,38 +12,42 @@
     AgentCoreMemoryStore,
 )
 
-# Conditional imports for checkpoint functionality
+# Conditional imports for Valkey functionality
 try:
+    from langgraph_checkpoint_aws.cache import ValkeyCache
     from langgraph_checkpoint_aws.checkpoint import AsyncValkeySaver, ValkeySaver
 
     valkey_available = True
 except ImportError:
     # If checkpoint dependencies are not available, create placeholder classes
     from typing import Any
 
-    def _missing_checkpoint_dependencies_error(*args: Any, **kwargs: Any) -> Any:
+    def _missing_dependencies_error(*args: Any, **kwargs: Any) -> Any:
         raise ImportError(
-            "Valkey checkpoint functionality requires optional dependencies. "
+            "Valkey functionality requires optional dependencies. "
             "Install them with: pip install 'langgraph-checkpoint-aws[valkey]'"
         )
 
     # Create placeholder classes that raise helpful errors
-    AsyncValkeySaver: type[Any] = _missing_checkpoint_dependencies_error  # type: ignore[assignment,no-redef]
-    ValkeySaver: type[Any] = _missing_checkpoint_dependencies_error  # type: ignore[assignment,no-redef]
+    AsyncValkeySaver: type[Any] = _missing_dependencies_error  # type: ignore[assignment,no-redef]
+    ValkeyCache: type[Any] = _missing_dependencies_error  # type: ignore[assignment,no-redef]
+    ValkeySaver: type[Any] = _missing_dependencies_error  # type: ignore[assignment,no-redef]
     valkey_available = False
 
 try:
     __version__ = version("langgraph-checkpoint-aws")
 except Exception:
     # Fallback version if package is not installed
-    __version__ = "1.0.0a1"
+    __version__ = "1.0.0"
 SDK_USER_AGENT = f"LangGraphCheckpointAWS#{__version__}"
 
 # Expose the saver class at the package level
 __all__ = [
     "AgentCoreMemorySaver",
     "AgentCoreMemoryStore",
     "AsyncValkeySaver",
+    "ValkeyCache",
     "ValkeySaver",
     "SDK_USER_AGENT",
+    "valkey_available",
 ]

libs/langgraph-checkpoint-aws/langgraph_checkpoint_aws/cache/__init__.py

@@ -0,0 +1,28 @@
+"""Cache implementations for LangGraph checkpoint AWS."""
+
+from typing import Any
+
+# Store the import error for later use
+_import_error: ImportError | None = None
+
+# Conditional imports for optional dependencies
+try:
+    from langgraph_checkpoint_aws.cache.valkey import ValkeyCache
+
+    __all__ = ["ValkeyCache"]
+except ImportError as e:
+    # Store the error for later use
+    _import_error = e
+
+    # If dependencies are not available, provide helpful error message
+    def _missing_dependencies_error(*args: Any, **kwargs: Any) -> Any:
+        raise ImportError(
+            "Valkey cache functionality requires optional dependencies. "
+            "Install them with: pip install 'langgraph-checkpoint-aws[valkey]'"
+        ) from _import_error
+
+    # Create placeholder classes that raise helpful errors
+    # Use type: ignore to suppress mypy errors for this intentional pattern
+    ValkeyCache: type[Any] = _missing_dependencies_error  # type: ignore[assignment,no-redef]
+
+    __all__ = ["ValkeyCache"]

libs/langgraph-checkpoint-aws/langgraph_checkpoint_aws/cache/valkey/__init__.py

@@ -0,0 +1,28 @@
+"""Valkey cache implementation for LangGraph checkpoint AWS."""
+
+from typing import Any
+
+# Store the import error for later use
+_import_error: ImportError | None = None
+
+# Conditional imports for optional dependencies
+try:
+    from .cache import ValkeyCache
+
+    __all__ = ["ValkeyCache"]
+except ImportError as e:
+    # Store the error for later use
+    _import_error = e
+
+    # If dependencies are not available, provide helpful error message
+    def _missing_dependencies_error(*args: Any, **kwargs: Any) -> Any:
+        raise ImportError(
+            "Valkey functionality requires optional dependencies. "
+            "Install them with: pip install 'langgraph-checkpoint-aws[valkey]'"
+        ) from _import_error
+
+    # Create placeholder classes that raise helpful errors
+    # Use type: ignore to suppress mypy errors for this intentional pattern
+    ValkeyCache: type[Any] = _missing_dependencies_error  # type: ignore[assignment,no-redef]
+
+    __all__ = ["ValkeyCache"]