[Docs] Clarify checkpointer options (#2328)

docs/docs/concepts/langgraph_cloud.md

@@ -1,12 +1,10 @@
 # Cloud SaaS
 
-!!! info "Prerequisites"
-    - [LangGraph Platform](./langgraph_platform.md)
-    - [LangGraph Server](./langgraph_server.md)
+!!! info "Prerequisites" - [LangGraph Platform](./langgraph_platform.md) - [LangGraph Server](./langgraph_server.md)
 
 ## Overview
 
-LangGraph's Cloud SaaS is a managed service that provides a scalable and secure environment for deploying LangGraph APIs. It is designed to work seamlessly with your LangGraph API regardless of how it is defined, what tools it uses, or any dependencies. Cloud SaaS provides a simple way to deploy and manage your LangGraph API in the cloud.
+LangGraph's Cloud SaaS is a managed service for deploying LangGraph APIs, regardless of its definition or dependencies. The service offers managed implementations of checkpointers and stores, allowing you to focus on building the right cognitive architecture for your use case. By handling scalable & secure infrastructure, LangGraph Cloud offers the fastest path to getting your LangGraph API deployed to production.
 
 ## Deployment
 
@@ -35,4 +33,4 @@ A high-level diagram of a Cloud SaaS deployment.
 
 ## Related
 
-- [Deployment Options](./deployment_options.md)
+- [Deployment Options](./deployment_options.md)

libs/langgraph/langgraph/graph/state.py

@@ -430,9 +430,11 @@ def compile(
         streamed, batched, and run asynchronously.
 
         Args:
-            checkpointer (Checkpointer): An optional checkpoint saver object.
-                This serves as a fully versioned "memory" for the graph, allowing
-                the graph to be paused and resumed, and replayed from any point.
+            checkpointer (Optional[Union[Checkpointer, Literal[False]]]): A checkpoint saver object or flag.
+                If provided, this Checkpointer serves as a fully versioned "short-term memory" for the graph,
+                allowing it to be paused, resumed, and replayed from any point.
+                If None, it may inherit the parent graph's checkpointer when used as a subgraph.
+                If False, it will not use or inherit any checkpointer.
             interrupt_before (Optional[Sequence[str]]): An optional list of node names to interrupt before.
             interrupt_after (Optional[Sequence[str]]): An optional list of node names to interrupt after.
             debug (bool): A flag indicating whether to enable debug mode.