Expose model switching (switch_profile) in agent-server REST API

openhands-agent-server/openhands/agent_server/conversation_router.py

@@ -288,6 +288,38 @@ async def set_conversation_security_analyzer(
     return Success()
 
 
+@conversation_router.post(
+    "/{conversation_id}/switch_profile",
+    responses={
+        400: {"description": "Invalid or corrupted profile"},
+        404: {"description": "Conversation or profile not found"},
+    },
+)
+async def switch_conversation_profile(
+    conversation_id: UUID,
+    profile_name: str = Body(..., embed=True),
+    conversation_service: ConversationService = Depends(get_conversation_service),
+) -> Success:
+    """Switch the conversation's LLM profile to a named profile."""
+    event_service = await conversation_service.get_event_service(conversation_id)
+    if event_service is None:
+        raise HTTPException(status.HTTP_404_NOT_FOUND)
+    conversation = event_service.get_conversation()
+    try:
+        conversation.switch_profile(profile_name)
+    except FileNotFoundError:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Profile '{profile_name}' not found",
+        )
+    except ValueError as e:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail=str(e),
+        )
+    return Success()
+
+
 @conversation_router.patch(
     "/{conversation_id}", responses={404: {"description": "Item not found"}}
 )

tests/agent_server/test_conversation_router.py

@@ -1,6 +1,6 @@
 """Tests for conversation_router.py endpoints."""
 
-from unittest.mock import AsyncMock
+from unittest.mock import AsyncMock, MagicMock
 from uuid import uuid4
 
 import pytest
@@ -1618,3 +1618,114 @@ def test_update_secrets_with_mixed_formats(
 
     finally:
         client.app.dependency_overrides.clear()
+
+
+# --- switch_profile endpoint tests ---
+
+
+def test_switch_conversation_profile_success(
+    client, mock_conversation_service, mock_event_service, sample_conversation_id
+):
+    """Test switch_conversation_profile endpoint with a valid profile."""
+    mock_conversation = MagicMock()
+    mock_conversation_service.get_event_service.return_value = mock_event_service
+    mock_event_service.get_conversation.return_value = mock_conversation
+
+    client.app.dependency_overrides[get_conversation_service] = (
+        lambda: mock_conversation_service
+    )
+
+    try:
+        response = client.post(
+            f"/api/conversations/{sample_conversation_id}/switch_profile",
+            json={"profile_name": "gpt"},
+        )
+
+        assert response.status_code == 200
+        assert response.json()["success"] is True
+
+        mock_conversation_service.get_event_service.assert_called_once_with(
+            sample_conversation_id
+        )
+        mock_event_service.get_conversation.assert_called_once()
+        mock_conversation.switch_profile.assert_called_once_with("gpt")
+    finally:
+        client.app.dependency_overrides.clear()
+
+
+def test_switch_conversation_profile_not_found(
+    client, mock_conversation_service, sample_conversation_id
+):
+    """Test switch_conversation_profile endpoint when conversation is not found."""
+    mock_conversation_service.get_event_service.return_value = None
+
+    client.app.dependency_overrides[get_conversation_service] = (
+        lambda: mock_conversation_service
+    )
+
+    try:
+        response = client.post(
+            f"/api/conversations/{sample_conversation_id}/switch_profile",
+            json={"profile_name": "gpt"},
+        )
+
+        assert response.status_code == 404
+        mock_conversation_service.get_event_service.assert_called_once_with(
+            sample_conversation_id
+        )
+    finally:
+        client.app.dependency_overrides.clear()
+
+
+def test_switch_conversation_profile_nonexistent_profile(
+    client, mock_conversation_service, mock_event_service, sample_conversation_id
+):
+    """Test switch_conversation_profile when the profile does not exist on disk."""
+    mock_conversation = MagicMock()
+    mock_conversation.switch_profile.side_effect = FileNotFoundError(
+        "Profile 'missing' not found"
+    )
+    mock_conversation_service.get_event_service.return_value = mock_event_service
+    mock_event_service.get_conversation.return_value = mock_conversation
+
+    client.app.dependency_overrides[get_conversation_service] = (
+        lambda: mock_conversation_service
+    )
+
+    try:
+        response = client.post(
+            f"/api/conversations/{sample_conversation_id}/switch_profile",
+            json={"profile_name": "missing"},
+        )
+
+        assert response.status_code == 404
+        assert "missing" in response.json()["detail"]
+        mock_conversation.switch_profile.assert_called_once_with("missing")
+    finally:
+        client.app.dependency_overrides.clear()
+
+
+def test_switch_conversation_profile_corrupted_profile(
+    client, mock_conversation_service, mock_event_service, sample_conversation_id
+):
+    """Test switch_conversation_profile when the profile is corrupted or invalid."""
+    mock_conversation = MagicMock()
+    mock_conversation.switch_profile.side_effect = ValueError("Invalid profile format")
+    mock_conversation_service.get_event_service.return_value = mock_event_service
+    mock_event_service.get_conversation.return_value = mock_conversation
+
+    client.app.dependency_overrides[get_conversation_service] = (
+        lambda: mock_conversation_service
+    )
+
+    try:
+        response = client.post(
+            f"/api/conversations/{sample_conversation_id}/switch_profile",
+            json={"profile_name": "corrupted"},
+        )
+
+        assert response.status_code == 400
+        assert "Invalid profile format" in response.json()["detail"]
+        mock_conversation.switch_profile.assert_called_once_with("corrupted")
+    finally:
+        client.app.dependency_overrides.clear()