Python: introduce workflow checkpointing (#366)

* Add workflow checkpointing functionality.

* Reintroduce protocol that went missing during merge

* Checkpoint updates

* Fix ordering of checkpointing

* Cleanup

* Cleanup - thanks Copilot

* Cleanup - thanks Copilot

* State reset updates

* State reset updates 2

* Workflow fixes and updates. Addressed PR feedback

* A few updates

python/packages/main/agent_framework/workflow/__init__.py

@@ -28,6 +28,10 @@ _IMPORTS = [
     "RequestInfoMessage",
     "WorkflowRunResult",
     "Workflow",
+    "FileCheckpointStorage",
+    "InMemoryCheckpointStorage",
+    "CheckpointStorage",
+    "WorkflowCheckpoint",
 ]
 
 

python/packages/main/agent_framework/workflow/__init__.pyi

@@ -6,15 +6,19 @@ from agent_framework_workflow import (
     AgentExecutorResponse,
     AgentRunEvent,
     AgentRunStreamingEvent,
+    CheckpointStorage,
     Executor,
     ExecutorCompletedEvent,
     ExecutorEvent,
     ExecutorInvokeEvent,
+    FileCheckpointStorage,
+    InMemoryCheckpointStorage,
     RequestInfoEvent,
     RequestInfoExecutor,
     RequestInfoMessage,
     Workflow,
     WorkflowBuilder,
+    WorkflowCheckpoint,
     WorkflowCompletedEvent,
     WorkflowContext,
     WorkflowEvent,
@@ -30,15 +34,19 @@ __all__ = [
     "AgentExecutorResponse",
     "AgentRunEvent",
     "AgentRunStreamingEvent",
+    "CheckpointStorage",
     "Executor",
     "ExecutorCompletedEvent",
     "ExecutorEvent",
     "ExecutorInvokeEvent",
+    "FileCheckpointStorage",
+    "InMemoryCheckpointStorage",
     "RequestInfoEvent",
     "RequestInfoExecutor",
     "RequestInfoMessage",
     "Workflow",
     "WorkflowBuilder",
+    "WorkflowCheckpoint",
     "WorkflowCompletedEvent",
     "WorkflowContext",
     "WorkflowEvent",