From 5910a6f86947b80b6abe0a6752e00d18c144632d Mon Sep 17 00:00:00 2001
From: Tao Chen <taochen@microsoft.com>
Date: Mon, 8 Jun 2026 14:57:01 -0700
Subject: [PATCH] Add reset to hosted workflow

---
 .../_responses.py                             |  6 ++
 .../foundry_hosting/tests/test_responses.py   | 75 +++++++++++++++++++
 2 files changed, 81 insertions(+)

diff --git a/python/packages/foundry_hosting/agent_framework_foundry_hosting/_responses.py b/python/packages/foundry_hosting/agent_framework_foundry_hosting/_responses.py
index ec4a9d8533..498879861b 100644
--- a/python/packages/foundry_hosting/agent_framework_foundry_hosting/_responses.py
+++ b/python/packages/foundry_hosting/agent_framework_foundry_hosting/_responses.py
@@ -649,6 +649,12 @@ class ResponsesHostServer(ResponsesAgentServerHost):
                     checkpoint_id=latest_checkpoint_id,
                     checkpoint_storage=restore_storage,
                 )
+        else:
+            # We reset the workflow if neither conversation_id nor previous_response_id
+            # was supplied, because this implies there's no prior state to restore and
+            # we want to ensure a clean slate. Workflow may contain in-memory state that
+            # needs to be cleared on new conversations.
+            await self._agent.workflow.reset_for_new_run()
 
         # Now run the agent with the latest input
         response_event_stream = ResponseEventStream(response_id=context.response_id, model=request.model)
diff --git a/python/packages/foundry_hosting/tests/test_responses.py b/python/packages/foundry_hosting/tests/test_responses.py
index 8bc09c5d13..df3aec0d65 100644
--- a/python/packages/foundry_hosting/tests/test_responses.py
+++ b/python/packages/foundry_hosting/tests/test_responses.py
@@ -3971,5 +3971,80 @@ class TestWorkflowAgentHosting:
         assert len(approval_responses) == 1
         assert approval_responses[0].approved is False  # type: ignore[attr-defined]
 
+    async def test_workflow_is_reset_when_no_prior_conversation(self) -> None:
+        """Without ``previous_response_id`` or ``conversation_id`` the host must
+        reset the workflow so any in-memory state from a previous request is
+        cleared before the new turn runs."""
+        workflow_agent = _build_text_workflow_agent("fresh")
+        server = _make_server(workflow_agent)
+
+        with patch.object(
+            workflow_agent.workflow,
+            "reset_for_new_run",
+            new=AsyncMock(wraps=workflow_agent.workflow.reset_for_new_run),
+        ) as reset_spy:
+            resp = await _post(server, input_text="hi", stream=False)
+
+        assert resp.status_code == 200
+        assert reset_spy.await_count == 1
+
+    async def test_workflow_is_reset_across_independent_requests(self) -> None:
+        """Two consecutive requests without a chaining context id must each
+        reset the workflow."""
+        workflow_agent = _build_text_workflow_agent("again")
+        server = _make_server(workflow_agent)
+
+        with patch.object(
+            workflow_agent.workflow,
+            "reset_for_new_run",
+            new=AsyncMock(wraps=workflow_agent.workflow.reset_for_new_run),
+        ) as reset_spy:
+            first = await _post(server, input_text="hi", stream=False)
+            second = await _post(server, input_text="hi again", stream=False)
+
+        assert first.status_code == 200
+        assert second.status_code == 200
+        assert reset_spy.await_count == 2
+
+    async def test_workflow_is_not_reset_when_resuming_from_checkpoint(self) -> None:
+        """When ``previous_response_id`` resolves to an existing workflow
+        checkpoint the host restores the checkpoint instead of resetting
+        the workflow."""
+        workflow_agent, _ = _build_approval_workflow_agent(
+            approval_request_id="apr_no_reset",
+            final_text="resumed",
+        )
+        server = _make_server(workflow_agent)
+
+        first = await _post(server, stream=False)
+        assert first.status_code == 200
+        first_body = first.json()
+        first_response_id = first_body["id"]
+        approval_request_id = next(it["id"] for it in first_body["output"] if it["type"] == "mcp_approval_request")
+
+        with patch.object(
+            workflow_agent.workflow,
+            "reset_for_new_run",
+            new=AsyncMock(wraps=workflow_agent.workflow.reset_for_new_run),
+        ) as reset_spy:
+            second = await _post_json(
+                server,
+                {
+                    "model": "test-model",
+                    "input": [
+                        {
+                            "type": "mcp_approval_response",
+                            "approval_request_id": approval_request_id,
+                            "approve": True,
+                        }
+                    ],
+                    "stream": False,
+                    "previous_response_id": first_response_id,
+                },
+            )
+
+        assert second.status_code == 200
+        assert reset_spy.await_count == 0
+
 
 # endregion