From 31f7b9409ad91ab61b51d4b96bccd56f5bf6d5b7 Mon Sep 17 00:00:00 2001
From: Daniel Meismer <daniel@zocdoc.com>
Date: Tue, 25 Aug 2026 15:51:59 -0400
Subject: [PATCH] fix(router): resolve hidden aliases for explicit lookup

Co-Authored-By: Codex
---
 litellm/router.py                             |  5 +--
 .../test_router_order_fallback.py             | 39 +++++++++++++++++++
 2 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/litellm/router.py b/litellm/router.py
index d07effd0d90..4609440a5cd 100644
--- a/litellm/router.py
+++ b/litellm/router.py
@@ -10644,10 +10644,9 @@ class Router:
                 _router_model_name: str = model_value
             elif isinstance(model_value, dict):
                 _model_value = RouterModelGroupAliasItem(**model_value)
-                if _model_value["hidden"] is True:
+                if _model_value["hidden"] is True and model_name is None:
                     continue
-                else:
-                    _router_model_name = _model_value["model"]
+                _router_model_name = _model_value["model"]
             else:
                 continue
 
diff --git a/tests/test_litellm/test_router_order_fallback.py b/tests/test_litellm/test_router_order_fallback.py
index 083f35456a3..7743cb005d0 100644
--- a/tests/test_litellm/test_router_order_fallback.py
+++ b/tests/test_litellm/test_router_order_fallback.py
@@ -367,6 +367,45 @@ async def test_router_order_fallback_with_wildcard_model_group():
     assert response._hidden_params["model_id"] == "2"
 
 
+@pytest.mark.asyncio
+async def test_router_order_fallback_with_hidden_model_group_alias():
+    router = Router(
+        model_list=[
+            {
+                "model_name": "canonical-model",
+                "litellm_params": {
+                    "model": "gpt-4o",
+                    "api_key": "bad",
+                    "mock_response": Exception("fail order 1"),
+                    "order": 1,
+                },
+                "model_info": {"id": "1"},
+            },
+            {
+                "model_name": "canonical-model",
+                "litellm_params": {
+                    "model": "gpt-4o",
+                    "api_key": "good",
+                    "mock_response": "success from order 2",
+                    "order": 2,
+                },
+                "model_info": {"id": "2"},
+            },
+        ],
+        model_group_alias={"hidden-alias": {"model": "canonical-model", "hidden": True}},
+        num_retries=0,
+    )
+
+    assert "hidden-alias" not in {deployment["model_name"] for deployment in router.get_model_list() or []}
+
+    response = await router.acompletion(
+        model="hidden-alias",
+        messages=[{"role": "user", "content": "hi"}],
+    )
+
+    assert response._hidden_params["model_id"] == "2"
+
+
 def test_check_non_standard_fallback_format():
     from litellm.router_utils.fallback_event_handlers import (
         _check_non_standard_fallback_format,