fix(proxy): keep chat on rows whose cost map entry serves chat

A row that carries the cost map key of an entry that serves chat counts as declaring nothing, so a catalog edit that adds a chat path never turns old Admin UI copies into 400s

litellm/proxy/route_llm_request.py

@@ -416,14 +416,27 @@ class _RouterFallbacks(Protocol):
     def fallbacks(self) -> Sequence[object] | None: ...
 
 
-def _echoed_from_cost_map(model_info: Mapping[str, object]) -> frozenset[str]:
+def _loaded_catalog_entry(model_info: Mapping[str, object]) -> Mapping[str, object]:
     catalog_key: Final = model_info.get(COST_MAP_LOOKUP_KEY)
     if not isinstance(catalog_key, str):
-        return frozenset()
-    return frozenset(
-        echoed_cost_map_fields(
-            model_info, GetModelCostMap.loaded_model_cost_map().get(catalog_key) or MappingProxyType({})
-        )
+        return MappingProxyType({})
+    return GetModelCostMap.loaded_model_cost_map().get(catalog_key) or MappingProxyType({})
+
+
+def _catalog_serves_chat(catalog_entry: Mapping[str, object]) -> bool:
+    try:
+        declared: Final = _DeploymentEndpointDeclaration.model_validate(dict(catalog_entry))
+    except ValidationError:
+        return False
+    return (declared.mode or "").strip().lower() in CHAT_SHAPED_MODES or not CHAT_SHAPED_ENDPOINTS.isdisjoint(
+        declared.supported_endpoints or ()
+    )
+
+
+def _declaration_overruled_by_catalog(model_info: Mapping[str, object]) -> bool:
+    catalog_entry: Final = _loaded_catalog_entry(model_info)
+    return _catalog_serves_chat(catalog_entry) or "supported_endpoints" in echoed_cost_map_fields(
+        model_info, catalog_entry
     )
 
 
@@ -439,7 +452,7 @@ def _declared_non_chat_endpoints(deployment: Mapping[str, object]) -> frozenset[
     endpoints: Final = frozenset(declared.supported_endpoints)
     if not endpoints.isdisjoint(CHAT_SHAPED_ENDPOINTS):
         return None
-    return None if "supported_endpoints" in _echoed_from_cost_map(model_info) else endpoints
+    return None if _declaration_overruled_by_catalog(model_info) else endpoints
 
 
 def _group_deployments(model: str, llm_router: LitellmRouter, team_id: str | None) -> tuple[Mapping[str, object], ...]:

tests/unit/proxy/test_route_llm_request.py

@@ -2061,6 +2061,45 @@ def test_endpoint_unsupported_ignores_endpoints_copied_from_the_loaded_catalog(d
     assert isinstance(_unsupported("acompletion", "catalog-row", router), ProxyUnsupportedEndpointError) is rejected
 
 
+def _catalog_key_serving_chat_by_mode() -> str:
+    return min(
+        key
+        for key, entry in GetModelCostMap.loaded_model_cost_map().items()
+        if entry.get("mode") == "chat" and "supported_endpoints" not in entry
+    )
+
+
+def _catalog_key_serving_chat_by_endpoints() -> str:
+    return min(
+        key
+        for key, entry in GetModelCostMap.loaded_model_cost_map().items()
+        if entry.get("mode") not in CHAT_SHAPED_MODES
+        and isinstance(endpoints := entry.get("supported_endpoints"), list)
+        and not CHAT_SHAPED_ENDPOINTS.isdisjoint(endpoints)
+    )
+
+
+@pytest.mark.parametrize(
+    "catalog_key, rejected",
+    [
+        pytest.param(_catalog_key_serving_chat_by_mode, False, id="key-of-a-chat-mode-catalog-entry"),
+        pytest.param(_catalog_key_serving_chat_by_endpoints, False, id="key-of-a-catalog-entry-listing-chat"),
+        pytest.param(_catalog_key_declaring_non_chat, True, id="key-of-a-non-chat-catalog-entry"),
+        pytest.param(lambda: "not-in-the-catalog", True, id="key-missing-from-the-catalog"),
+    ],
+)
+def test_endpoint_unsupported_ignores_non_chat_values_on_a_row_whose_catalog_entry_serves_chat(catalog_key, rejected):
+    router: Final = _router_with(
+        {
+            "model_name": "catalog-row",
+            "litellm_params": {"model": "openai/catalog-row", "api_key": "test-key"},
+            "model_info": {"key": catalog_key(), **EMBEDDING_ONLY},
+        }
+    )
+
+    assert isinstance(_unsupported("acompletion", "catalog-row", router), ProxyUnsupportedEndpointError) is rejected
+
+
 class _LookupCountingRouter(Router):
     def __init__(self, **router_kwargs: object) -> None:
         self.looked_up: list[str | None] = []