Python: Python : checkpoint restore +pending request deserialization failure when hosting workflow as agent with ResponsesHostserver in foundry

[dgsear]

Scenario

This occurs when a workflow is hosted as an agent via ResponseHostServer (Response protocol), aand the workflow is resumed across requests using previous_response_id

when it happened

• During the hosted-agent execution (work-as-agent ), sfter a prior turn produced request_info and pending requests.
• on the next /responses call with previous_response_id + function_call_output, the server restored checkpoint state and failed on deserializing a pending request type.

observed behaviour

• checkpoint decode warning:
  checkpoint deserialization blocked for type 'agent_framework_orchestrations._handoff:HandoffAgentUserRequest'
  checkpoint deserialization blocked for type agent_framework_orchestrations._magentic:MagenticPlanReviewRequest

• Restore proceeded from an older/other checkpoint state

• Follow-up response was rejected

• `ValueError :Response provided for unknown request Id :<request_id>

Expected

When hosting workflow as agent:
-pending request checkpoint state should restore reliably across turns

Package versions:
agent-framework-core==1.13.0
agent-framework-foundry-hosting==1.0.0.b260730

[github-actions]

🤖 Automated triage reproduction notes (agent-authored — trust but verify)

Agent analysis

Repro: _RestrictedUnpickler.find_class() in packages/core/agent_framework/_workflows/_checkpoint_encoding.py (line 200) rejects types from agent_framework_orchestrations.* because _FRAMEWORK_MODULE_PREFIX on line 72 is "agent_framework." which doesn't match "agent_framework_orchestrations." (underscore vs dot). Triggered when FileCheckpointStorage (or any storage passing allowed_types != None) deserializes a checkpoint containing HandoffAgentUserRequest or MagenticPlanReviewRequest. Minimal repro: encode a HandoffAgentUserRequest via encode_checkpoint_value then decode with allowed_types=frozenset() — the restricted unpickler raises "deserialization blocked".

• Failing test: python/packages/core/tests/workflow/test_checkpoint_orchestrations_deserialization.py
• Files examined: python/packages/core/agent_framework/_workflows/_checkpoint_encoding.py, python/packages/core/agent_framework/_workflows/_checkpoint.py, python/packages/foundry_hosting/agent_framework_foundry_hosting/_state_store.py, python/packages/foundry_hosting/agent_framework_foundry_hosting/_responses.py, python/packages/orchestrations/agent_framework_orchestrations/_handoff.py
• Tests run: python/packages/core/tests/workflow/test_checkpoint_orchestrations_deserialization.py
• Reported version: agent-framework-core==1.13.0, agent-framework-foundry-hosting==1.0.0.b260730
• Current version: agent-framework-core==1.13.0, agent-framework-foundry-hosting==1.0.0b260730

[uuzzrm]

I can prepare a focused fix for this. The triage notes point to the checkpoint allowlist rejecting �gent_framework_orchestrations.* because it only matches the dotted �gent_framework. prefix. I’ll verify the repro on current main, add a regression test for the affected pending request types, and keep the change limited to checkpoint deserialization.