Merge pull request #38624 from BerriAI/litellm_/circleci-regressions-review-f0a542

fix(exceptions): keep a refused connection an APIConnectionError

litellm/litellm_core_utils/exception_mapping_utils.py

@@ -2222,6 +2222,8 @@ def _map_exception_by_status(
     status_code: Final = original_exception.status_code if hasattr(original_exception, "status_code") else None
     if not isinstance(status_code, int) or status_code < 400:
         return
+    if getattr(original_exception, "status_code_is_synthesized", False):
+        return
     message: Final = f"{exception_provider} - {error_str}"
     response: Final = original_exception.response if hasattr(original_exception, "response") else None
     match status_code:

litellm/llms/base_llm/chat/transformation.py

@@ -46,8 +46,10 @@ class BaseLLMException(Exception):
         request: httpx.Request | None = None,
         response: httpx.Response | None = None,
         body: dict | None = None,
+        status_code_is_synthesized: bool = False,
     ):
         self.status_code = status_code
+        self.status_code_is_synthesized = status_code_is_synthesized
         self.message: str = message
         self.headers = headers
         if request:

litellm/llms/custom_httpx/llm_http_handler.py

@@ -5947,11 +5947,13 @@ class BaseLLMHTTPHandler:
             BaseEvalsAPIConfig,
         ],
     ):
-        status_code = getattr(e, "status_code", 500)
+        received_status_code: Final = (
+            e.response.status_code if isinstance(e, httpx.HTTPStatusError) else getattr(e, "status_code", None)
+        )
+        status_code = received_status_code if isinstance(received_status_code, int) else 500
         error_headers = getattr(e, "headers", None)
         if isinstance(e, httpx.HTTPStatusError):
             error_text = e.response.text
-            status_code = e.response.status_code
         else:
             error_text = getattr(e, "text", str(e))
         error_response: Final = getattr(e, "response", None)
@@ -5971,13 +5973,17 @@ class BaseLLMHTTPHandler:
                 status_code=status_code,
                 message=error_text,
                 headers=error_headers,
+                status_code_is_synthesized=not isinstance(received_status_code, int),
             )
 
-        raise provider_config.get_error_class(
+        provider_error: Final = provider_config.get_error_class(
             error_message=error_text,
             status_code=status_code,
             headers=error_headers,
         )
+        if not isinstance(received_status_code, int):
+            provider_error.status_code_is_synthesized = True
+        raise provider_error
 
     @staticmethod
     def _append_query_params(url: str, query_params: RealtimeQueryParams | None) -> str:

tests/test_litellm/litellm_core_utils/test_exception_mapping_utils.py

@@ -1163,3 +1163,52 @@ def test_bedrock_mantle_context_overflow_maps_to_context_window_exceeded():
 
     assert excinfo.value.status_code == 400
     assert "prompt is too long: 1055489 tokens > 1050000 maximum" in excinfo.value.message
+
+
+def test_branchless_provider_transport_error_maps_to_api_connection_error():
+    from litellm.llms.base_llm.chat.transformation import BaseLLMException
+
+    original_exception = BaseLLMException(status_code=500, message="[Errno 111] Connection refused")
+    original_exception.status_code_is_synthesized = True
+
+    with pytest.raises(litellm.APIConnectionError):
+        exception_type(
+            model="test-agent",
+            original_exception=original_exception,
+            custom_llm_provider="a2a",
+        )
+
+
+def test_branchless_provider_upstream_500_still_maps_to_internal_server_error():
+    from litellm.llms.base_llm.chat.transformation import BaseLLMException
+
+    original_exception = BaseLLMException(status_code=500, message="upstream exploded")
+
+    with pytest.raises(litellm.InternalServerError):
+        exception_type(
+            model="test-agent",
+            original_exception=original_exception,
+            custom_llm_provider="a2a",
+        )
+
+
+def test_handle_error_marks_only_a_status_code_it_never_received():
+    from litellm.llms.custom_httpx.llm_http_handler import BaseLLMHTTPHandler
+
+    handler = BaseLLMHTTPHandler()
+
+    with pytest.raises(litellm.llms.base_llm.chat.transformation.BaseLLMException) as transport:
+        raise handler._handle_error(e=httpx.ConnectError("Connection refused"), provider_config=None)
+    assert transport.value.status_code == 500
+    assert transport.value.status_code_is_synthesized is True
+
+    request = httpx.Request(method="POST", url="https://example.invalid")
+    upstream = httpx.HTTPStatusError(
+        "server error",
+        request=request,
+        response=httpx.Response(status_code=500, request=request, text="upstream exploded"),
+    )
+    with pytest.raises(litellm.llms.base_llm.chat.transformation.BaseLLMException) as received:
+        raise handler._handle_error(e=upstream, provider_config=None)
+    assert received.value.status_code == 500
+    assert received.value.status_code_is_synthesized is False

tests/test_litellm/llms/base_llm/search/test_base_search_transformation.py

@@ -322,7 +322,7 @@ async def test_query_param_key_not_leaked_with_dummy_caller_key(
         "litellm.llms.custom_httpx.http_handler.AsyncHTTPHandler.get",
         fake_get,
     ):
-        with pytest.raises(litellm.InternalServerError):
+        with pytest.raises(litellm.APIConnectionError):
             await litellm.asearch(
                 query="secrets",
                 search_provider=provider,