Merge 7d93569fbf into e9b1c11098

litellm/messages/dispatch.py

@@ -123,6 +123,7 @@ def messages_target(model: str, custom_llm_provider: str | None, model_info: obj
 _FEATURES: Final[detectors.Detectors] = MappingProxyType(
     {
         **detectors.COMMON,
+        Feature.TIMEOUT_VARIANTS: route_detectors.timeout_variants,
         Feature.PROVIDER_AFFINITY: route_detectors.provider_affinity,
         Feature.SAFEGUARDS_CLASSIFIER: route_detectors.safeguards_classifier,
         Feature.RESPONSE_CACHE: detectors.response_cache,

litellm/rust_bridge/catalog.py

@@ -39,7 +39,7 @@ class Feature(str, Enum):
     PROXY_MCP_TOOLS = "proxy_mcp_tools"
     """litellm_proxy MCP tools that Python expands and may auto-execute."""
     CALLER_CLIENT = "caller_client"
-    """A caller-supplied HTTP client or shared session that Python sends through."""
+    """A caller-supplied HTTP client that Python sends through."""
     TIMEOUT_VARIANTS = "timeout_variants"
     """request_timeout, stream_timeout or httpx.Timeout phases beyond a plain timeout."""
     DROP_PARAMS = "drop_params"

litellm/rust_bridge/detectors.py

@@ -44,8 +44,8 @@ def latest_alias(request: NativeCall) -> bool:
 
 
 def caller_client(request: NativeCall) -> bool:
-    """Python sends through the caller's HTTP client or shared session."""
-    return present(request, "client") or present(request, "shared_session")
+    """Python sends through the caller's HTTP client; a shared session only reuses connections, which native pools."""
+    return present(request, "client")
 
 
 def extra_body(request: NativeCall) -> bool:

litellm/rust_bridge/messages/detectors.py

@@ -4,6 +4,8 @@ from __future__ import annotations
 
 from typing import Final
 
+import httpx
+
 import litellm
 from litellm.anthropic_beta_headers_manager import is_foundry_api_base
 from litellm.litellm_core_utils.core_helpers import drops_unsupported_params
@@ -12,6 +14,10 @@ from litellm.rust_bridge.detectors import api_base, overridden, present, streami
 from litellm.rust_bridge.public_call import NativeCall, optional_mapping, optional_sequence, optional_str
 
 
+def timeout_variants(request: NativeCall) -> bool:
+    return present(request, "request_timeout") or isinstance(request.resolved.get("timeout"), httpx.Timeout)
+
+
 def provider_affinity(request: NativeCall) -> bool:
     return is_opencode_api_base(api_base(request))
 

tests/test_litellm_rust/messages/test_dispatch.py

@@ -528,6 +528,36 @@ def test_each_detected_feature_reaches_its_rule(
     assert served(kwargs) is python_result
 
 
+@pytest.mark.parametrize(
+    "kwargs",
+    (
+        pytest.param({"shared_session": object()}, id="proxy-shared-session"),
+        pytest.param({"stream": True, "timeout": 600.0, "stream_timeout": 600.0}, id="proxy-stream-timeout"),
+    ),
+)
+def test_proxy_request_shape_stays_native(kwargs: Mapping[str, object]) -> None:
+    rules: Final[Rules] = (
+        RouteRule(
+            Route.MESSAGES, Rollout.PYTHON_ONLY, features=frozenset({Feature.CALLER_CLIENT, Feature.TIMEOUT_VARIANTS})
+        ),
+        RouteRule(Route.MESSAGES, Rollout.RUST_REQUIRED),
+    )
+    native_result: Final = response()
+
+    def python(*call_args: object, **call_kwargs: object) -> AnthropicMessagesResponse:  # kwargs-ok: rejected fallback
+        pytest.fail("A proxy-shaped request must not fall back to Python")
+
+    served: Final = _DISPATCH.run(
+        (16, MESSAGES, "anthropic/claude-sonnet-4-5"),
+        kwargs,
+        python=python,
+        binding=messages_binding(lambda request: native_result),
+        native=lambda hook, request, call_args, native_kwargs: hook(request),
+        rules=rules,
+    )
+    assert served is native_result
+
+
 @pytest.mark.asyncio
 @pytest.mark.parametrize(
     "kwargs",

tests/test_litellm_rust/responses/test_dispatch.py

@@ -260,7 +260,6 @@ ENCODED_ID: Final = ResponsesAPIRequestUtils._build_encrypted_item_id("deploymen
         (Feature.MOCK_RESPONSE, {"mock_response": "hi"}, {}),
         (Feature.PROXY_MCP_TOOLS, {"tools": [{"type": "mcp", "server_label": "g", "server_url": "litellm_proxy"}]}, {}),
         (Feature.CALLER_CLIENT, {"client": object()}, {}),
-        pytest.param(Feature.CALLER_CLIENT, {"shared_session": object()}, {}, id="shared-session"),
         pytest.param(Feature.EXTRA_BODY, {"extra_body": {"stream": True}}, {}, id="extra-body-stream"),
         pytest.param(
             Feature.PROVIDER_AFFINITY,

tests/unit/rust_bridge/test_detectors.py

@@ -109,7 +109,7 @@ def _wrap_nested_level(value: object, depth: int) -> object:
         (detectors.prompt_management, {"model": "litellm_agent/gpt-5"}, True),
         (detectors.prompt_management, {"model": "gpt-5"}, False),
         (detectors.caller_client, {"client": object()}, True),
-        (detectors.caller_client, {"shared_session": object()}, True),
+        (detectors.caller_client, {"shared_session": object()}, False),
         (detectors.caller_client, {"client": None, "shared_session": None}, False),
         (detectors.caller_client, {}, False),
         (detectors.extra_body, {"extra_body": {"stream": True}}, True),