New user route user_id conflict handling

litellm/proxy/management_endpoints/internal_user_endpoints.py

@@ -101,35 +101,75 @@ def _update_internal_new_user_params(data_json: dict, data: NewUserRequest) -> d
     return data_json
 
 
+async def _check_duplicate_user_field(
+    field_name: str,
+    field_value: Optional[str],
+    prisma_client: Any,
+    *,
+    case_insensitive: bool = False,
+    label: Optional[str] = None,
+) -> None:
+    """
+    Helper function to check if a field already exists in the user table.
+
+    Args:
+        field_name (str): Database field name to check.
+        field_value (Optional[str]): Value to check for duplicates.
+        prisma_client (Any): Database client instance.
+        case_insensitive (bool): Whether to use case-insensitive comparison.
+        label (Optional[str]): Human readable label for error messages.
+
+    Raises:
+        Exception: If database is not connected.
+        HTTPException: If a user with the given field value already exists.
+    """
+    if field_value:
+        if prisma_client is None:
+            raise Exception("Database not connected")
+
+        value = field_value.strip()
+        where_clause = {field_name: {"equals": value}}
+        if case_insensitive:
+            where_clause[field_name]["mode"] = "insensitive"
+
+        existing_user = await prisma_client.db.litellm_usertable.find_first(
+            where=where_clause
+        )
+
+        if existing_user is not None:
+            existing_value = getattr(existing_user, field_name, value)
+            error_label = label or field_name
+            raise HTTPException(
+                status_code=409,
+                detail={"error": f"User with {error_label} {existing_value} already exists"},
+            )
+
+
 async def _check_duplicate_user_email(
     user_email: Optional[str], prisma_client: Any
 ) -> None:
     """
     Helper function to check if a user email already exists in the database.
-
-    Args:
-        user_email (Optional[str]): Email to check
-        prisma_client (Any): Database client instance
-
-    Raises:
-        Exception: If database is not connected
-        HTTPException: If user with email already exists
     """
-    if user_email:
-        if prisma_client is None:
-            raise Exception("Database not connected")
+    await _check_duplicate_user_field(
+        field_name="user_email",
+        field_value=user_email,
+        prisma_client=prisma_client,
+        case_insensitive=True,
+        label="email",
+    )
 
-        existing_user = await prisma_client.db.litellm_usertable.find_first(
-            where={"user_email": {"equals": user_email.strip(), "mode": "insensitive"}}
-        )
 
-        if existing_user is not None:
-            raise HTTPException(
-                status_code=400,
-                detail={
-                    "error": f"User with email {existing_user.user_email} already exists"
-                },
-            )
+async def _check_duplicate_user_id(user_id: Optional[str], prisma_client: Any) -> None:
+    """
+    Helper function to check if a user id already exists in the database.
+    """
+    await _check_duplicate_user_field(
+        field_name="user_id",
+        field_value=user_id,
+        prisma_client=prisma_client,
+        label="id",
+    )
 
 
 async def _add_user_to_organizations(
@@ -361,7 +401,8 @@ async def new_user(
                 status_code=500,
                 detail=CommonProxyErrors.db_not_connected_error.value,
             )
-        # Check for duplicate email
+        # Check for duplicate user_id or email
+        await _check_duplicate_user_id(data.user_id, prisma_client)
         await _check_duplicate_user_email(data.user_email, prisma_client)
 
         # Check if license is over limit

tests/test_litellm/proxy/management_endpoints/test_internal_user_endpoints.py

@@ -261,14 +261,21 @@ async def test_new_user_license_over_limit(mocker):
 
     mock_prisma_client.db.litellm_usertable.count = mock_count
 
-    # Mock check_duplicate_user_email to pass
+    # Mock duplicate checks to pass
     async def mock_check_duplicate_user_email(*args, **kwargs):
         return None  # No duplicate found
 
+    async def mock_check_duplicate_user_id(*args, **kwargs):
+        return None  # No duplicate found
+
     mocker.patch(
         "litellm.proxy.management_endpoints.internal_user_endpoints._check_duplicate_user_email",
         mock_check_duplicate_user_email,
     )
+    mocker.patch(
+        "litellm.proxy.management_endpoints.internal_user_endpoints._check_duplicate_user_id",
+        mock_check_duplicate_user_id,
+    )
 
     # Mock the license check to return True (over limit)
     mock_license_check = mocker.MagicMock()
@@ -449,14 +456,21 @@ async def test_new_user_default_teams_flow(mocker):
 
     mock_prisma_client.db.litellm_usertable.count = mock_count
 
-    # Mock check_duplicate_user_email to pass
+    # Mock duplicate checks to pass
     async def mock_check_duplicate_user_email(*args, **kwargs):
         return None  # No duplicate found
 
+    async def mock_check_duplicate_user_id(*args, **kwargs):
+        return None  # No duplicate found
+
     mocker.patch(
         "litellm.proxy.management_endpoints.internal_user_endpoints._check_duplicate_user_email",
         mock_check_duplicate_user_email,
     )
+    mocker.patch(
+        "litellm.proxy.management_endpoints.internal_user_endpoints._check_duplicate_user_id",
+        mock_check_duplicate_user_id,
+    )
 
     # Mock the license check to return False (under limit)
     mock_license_check = mocker.MagicMock()
@@ -737,7 +751,7 @@ async def test_check_duplicate_user_email_case_insensitive(mocker):
     with pytest.raises(HTTPException) as exc_info:
         await _check_duplicate_user_email("user@example.com", mock_prisma_client)
 
-    assert exc_info.value.status_code == 400
+    assert exc_info.value.status_code == 409
     assert "User with email User@Example.com already exists" in str(
         exc_info.value.detail
     )
@@ -770,6 +784,56 @@ async def test_check_duplicate_user_email_case_insensitive(mocker):
     )  # Should not raise exception
 
 
+@pytest.mark.asyncio
+async def test_check_duplicate_user_id(mocker):
+    """
+    Test that _check_duplicate_user_id detects duplicates and does not use case insensitive matching.
+    """
+    from fastapi import HTTPException
+
+    from litellm.proxy.management_endpoints.internal_user_endpoints import (
+        _check_duplicate_user_id,
+    )
+
+    mock_prisma_client = mocker.MagicMock()
+
+    # Duplicate user_id should raise
+    mock_existing_user = mocker.MagicMock()
+    mock_existing_user.user_id = "existing-user-id"
+
+    async def mock_find_first_duplicate(*args, **kwargs):
+        where_clause = kwargs.get("where", {})
+        user_id_clause = where_clause.get("user_id", {})
+        assert user_id_clause.get("equals") == "existing-user-id"
+        assert "mode" not in user_id_clause
+        return mock_existing_user
+
+    mock_prisma_client.db.litellm_usertable.find_first = mock_find_first_duplicate
+
+    with pytest.raises(HTTPException) as exc_info:
+        await _check_duplicate_user_id("existing-user-id", mock_prisma_client)
+
+    assert exc_info.value.status_code == 409
+    assert "User with id existing-user-id already exists" in str(
+        exc_info.value.detail
+    )
+
+    # No duplicate should pass
+    async def mock_find_first_no_duplicate(*args, **kwargs):
+        where_clause = kwargs.get("where", {})
+        user_id_clause = where_clause.get("user_id", {})
+        assert user_id_clause.get("equals") == "new-user-id"
+        assert "mode" not in user_id_clause
+        return None
+
+    mock_prisma_client.db.litellm_usertable.find_first = mock_find_first_no_duplicate
+
+    await _check_duplicate_user_id("new-user-id", mock_prisma_client)
+
+    # None user_id should no-op
+    await _check_duplicate_user_id(None, mock_prisma_client)
+
+
 def test_process_keys_for_user_info_filters_dashboard_keys(monkeypatch):
     """
     Test that _process_keys_for_user_info filters out keys with team_id='litellm-dashboard'