fix(router): restore four base behaviors the RoutingContext refactor changed (#49395)

litellm/router_strategy/auto_router/litellm_encoder.py

@@ -14,13 +14,13 @@ else:
     RoutingContext = Any
 
 
-def litellm_to_list(embeds: litellm.EmbeddingResponse) -> list[list[float]]:
+def litellm_to_list(embeds: object) -> list[list[float]]:
     """Convert a LiteLLM embedding response to a list of embeddings.
 
     :param embeds: The LiteLLM embedding response.
     :return: A list of embeddings.
     """
-    if not embeds or not embeds.data:
+    if not embeds or not isinstance(embeds, litellm.EmbeddingResponse) or not embeds.data:
         raise ValueError("No embeddings found in LiteLLM embedding response.")
     return [x["embedding"] for x in embeds.data]
 

litellm/router_strategy/complexity_router/jev_classifier.py

@@ -68,6 +68,7 @@ class JevBudgetedRequest:
     telemetry: StandardLoggingRoutingDecision
 
 
+@renamed_router_param("router", "context")
 def jev_input_targets(context: "RoutingContext", config: "OpenSourceClassifierConfig") -> tuple[JevInputTarget, ...]:
     from litellm.types.router import Deployment
 

litellm/router_strategy/tag_based_routing.py

@@ -392,9 +392,11 @@ def _resolve_constraint_only_pool(
 
 def _all_deployments_or_fallback(
     ctx: "RoutingContext",
-    model: str,
+    model: str | None,
     fallback: _DeploymentPool,
 ) -> Sequence[_DeploymentLike | DeploymentTypedDict] | Mapping[_DeploymentLike, object]:
+    if model is None:  # a group of no name has no deployments, it is not a failed lookup
+        return ()
     try:
         return ctx.registry().deployments(model, source="all")
     except Exception:  # noqa: BLE001  # fail safe toward today's healthy-only behavior on lookup errors

litellm/router_utils/handle_error.py

@@ -23,7 +23,7 @@ else:
 
 @renamed_router_param("litellm_router_instance")
 async def send_llm_exception_alert(
-    ctx: "RoutingContext",
+    ctx: "RoutingContext | None",
     request_kwargs: dict,
     error_traceback_str: str,
     original_exception,
@@ -39,6 +39,9 @@ async def send_llm_exception_alert(
     Returns:
         None
     """
+    if ctx is None:
+        return
+
     slack_alerting_logger: Final = ctx.observers().slack_alerting_logger
     if slack_alerting_logger is None:
         return

tests/unit/router_strategy/complexity_router/test_jev_classifier.py

@@ -1316,3 +1316,24 @@ async def test_jev_open_breaker_preserves_input_budget_in_fallback_decision(fall
         transport.handle_async_request.assert_awaited_once()
     finally:
         await handler.client.aclose()
+
+
+def test_jev_input_targets_still_takes_a_router_with_a_deprecation_warning() -> None:
+    from litellm.router_strategy.complexity_router.jev_classifier import jev_input_targets
+
+    router = litellm.Router(
+        model_list=[
+            {
+                "model_name": "decision-deployment",
+                "litellm_params": {"model": "openai/gpt-4o-mini", "api_key": "sk-test"},
+                "model_info": {"id": "d1", "max_input_tokens": 1234},
+            }
+        ]
+    )
+    config = JevClassifierConfig.model_validate({"deployment_name": "decision-deployment"})
+
+    with pytest.warns(DeprecationWarning, match="pass context"):
+        old_way = jev_input_targets(router, config)
+
+    assert old_way == jev_input_targets(router._core_ctx, config)
+    assert [target.max_tokens for target in old_way] == [1234]

tests/unit/router_strategy/test_litellm_encoder.py

@@ -134,3 +134,19 @@ class TestEmbeddingInputCap:
         _encoder(router, max_input_chars=20).encode_queries(["route me please, then a huge pasted file"])
 
         assert router.embedded_inputs == [["route me please, the"]]
+
+
+@pytest.mark.parametrize(
+    "embeds",
+    [
+        {"data": [{"embedding": [0.1]}]},
+        [{"embedding": [0.1]}],
+        type("HasData", (), {"data": [{"embedding": [0.1]}]})(),
+    ],
+    ids=["dict", "list", "object-with-data"],
+)
+def test_litellm_to_list_rejects_anything_but_an_embedding_response(embeds: object) -> None:
+    from litellm.router_strategy.auto_router.litellm_encoder import litellm_to_list
+
+    with pytest.raises(ValueError, match="No embeddings found"):
+        litellm_to_list(embeds)

tests/unit/router_strategy/test_router_tag_routing.py

@@ -1225,6 +1225,32 @@ def test_chain_tag_filtering_override_falls_back_to_healthy_deployments_on_looku
     assert _chain_tag_filtering_override(_BrokenCtx(), "gpt-4", healthy_deployments) is False
 
 
+@pytest.mark.asyncio()
+async def test_get_deployments_for_tag_without_a_model_keeps_the_router_wide_setting():
+    # model=None names no group, so no group-level enable_tag_filtering applies: the router-wide
+    # setting (off here) decides, even when a healthy deployment opts in on its own
+    router = litellm.Router(
+        model_list=[
+            {
+                "model_name": "gpt-4",
+                "litellm_params": {"model": "gpt-4o", "api_key": "sk-test", "tags": ["teamA"]},
+                "model_info": {"id": "a", "enable_tag_filtering": True},
+            }
+        ]
+    )
+    healthy_deployments = router.registry().deployments("gpt-4", source="all")
+
+    picked = await get_deployments_for_tag(
+        router._core_ctx,
+        None,  # pyright: ignore[reportArgumentType]  # a direct caller passing no model
+        healthy_deployments,
+        request_kwargs={"metadata": {"tags": ["zzz"]}},
+        request_deployments=healthy_deployments,
+    )
+
+    assert [d["model_info"]["id"] for d in picked] == ["a"]
+
+
 @pytest.mark.asyncio()
 async def test_chain_enable_tag_filtering_true_overrides_router_level_false():
     # Router-wide tag filtering is off; this model group opts in on its own via

tests/unit/router_utils/test_handle_error.py

@@ -273,3 +273,10 @@ def setup_and_teardown():
     yield
     loop.close()
     asyncio.set_event_loop(None)
+
+
+@pytest.mark.asyncio
+async def test_send_llm_exception_alert_without_a_router_does_nothing():
+    from litellm.router_utils.handle_error import send_llm_exception_alert
+
+    assert await send_llm_exception_alert(None, {"model": "gpt-5-mini"}, "traceback", Exception("boom")) is None

tests/unit/test_router/core/test_endpoints.py

@@ -414,6 +414,8 @@ def _scripted_stream(*texts: str) -> Callable[..., CustomStreamWrapper]:
         async def chunks() -> AsyncIterator[ModelResponseStream]:
             for text in texts:
                 yield ModelResponseStream(choices=[{"index": 0, "delta": {"role": "assistant", "content": text}}])
+            # A stream that ends without a finish reason fails since #47665.
+            yield ModelResponseStream(choices=[{"index": 0, "delta": {}, "finish_reason": "stop"}])
             yield ModelResponseStream(choices=[{"index": 0, "delta": {}, "finish_reason": "stop"}])
 
         logging_obj: Final = LiteLLMLogging(