fix(proxy): let llm_api keys read /model_group/info

Keys created with key_type=llm_api get allowed_routes=["llm_api_routes"],
which covered /v1/models and /model/info but not /model_group/info, so an
OpenAI-compatible client could list models yet got a 403 when reading the
group-level pricing, mode and context-window metadata it needs at request
time (BerriAI/litellm#37810).

Adds model_group_info_routes as a new LiteLLMRoutes member included in
llm_api_routes only. As with /model/info, membership there is not the same
as RouteChecks.is_llm_api_route(), so budget reservation, cost tracking and
DISABLE_LLM_API_ENDPOINTS are unaffected; common_checks already treats the
path as spend-free via MODEL_DISCOVERY_ROUTES. The handler scopes its
response to the caller's model access and returns no api_base or
credentials. /v2/model/info stays out: it is the paginated Admin UI
deployment listing, per the scope set in 7d6ee2a9c

litellm/proxy/_types.py

@@ -567,6 +567,10 @@ class LiteLLMRoutes(enum.Enum):
         "/v1/model/info",
     ]
 
+    model_group_info_routes = [
+        "/model_group/info",
+    ]
+
     llm_api_routes = (
         openai_routes
         + anthropic_routes
@@ -578,6 +582,7 @@ class LiteLLMRoutes(enum.Enum):
         + litellm_native_routes
         + list(agent_inference_routes)
         + model_info_routes
+        + model_group_info_routes
     )
     info_routes = [
         "/key/info",

tests/test_litellm/proxy/auth/test_route_checks.py

@@ -527,9 +527,31 @@ def test_virtual_key_llm_api_routes_allows_model_info(route):
     assert result is True
 
 
-@pytest.mark.parametrize("route", ["/model/info", "/v1/model/info"])
+@pytest.mark.parametrize("route", ["/model_group/info"])
+def test_virtual_key_llm_api_routes_allows_model_group_info(route):
+    """AI API virtual keys must be able to read group-level model metadata
+    (pricing, mode, context window) for the groups they can already call.
+    The handler scopes its response to the caller's model access and returns
+    no api_base or credentials.
+    """
+
+    valid_token = UserAPIKeyAuth(
+        user_id="test_user",
+        allowed_routes=["llm_api_routes"],
+    )
+
+    result = RouteChecks.is_virtual_key_allowed_to_call_route(
+        route=route,
+        valid_token=valid_token,
+        request=_mock_request("GET"),
+    )
+
+    assert result is True
+
+
+@pytest.mark.parametrize("route", ["/model/info", "/v1/model/info", "/model_group/info"])
 def test_model_info_not_classified_as_llm_api(route):
-    """Membership in `llm_api_routes` must not promote /model/info to an
+    """Membership in `llm_api_routes` must not promote model-metadata reads to an
     `is_llm_api_route()`. That predicate gates DISABLE_LLM_API_ENDPOINTS,
     global/virtual-key budget enforcement, enforce_user_param and the JWT
     x-litellm-team-id attachment; model metadata is a free read and must stay
@@ -539,10 +561,10 @@ def test_model_info_not_classified_as_llm_api(route):
     assert RouteChecks.is_llm_api_route(route=route) is False
 
 
-@pytest.mark.parametrize("route", ["/v2/model/info", "/model_group/info"])
+@pytest.mark.parametrize("route", ["/v2/model/info"])
 def test_virtual_key_llm_api_routes_denies_other_model_info_routes(route):
-    """The grant is scoped to the two /model/info paths. The paginated Admin UI
-    listing and the model-group endpoint stay outside it.
+    """The grant covers /model_group/info (group-level metadata scoped to the
+    caller's model access) but not the paginated Admin UI deployment listing.
     """
 
     valid_token = UserAPIKeyAuth(