fix(decisions): preserve upstream error body and response on decisions exception mapping (fixes #48539)

Signed-off-by: gauravatwork117 <gauravatwork117@gmail.com>

litellm/litellm_core_utils/exception_mapping_utils.py

@@ -2328,6 +2328,7 @@ def _map_exception_by_status(
         return
     message: Final = f"{exception_provider} - {error_str}"
     response: Final = original_exception.response if hasattr(original_exception, "response") else None
+    body: Final = getattr(original_exception, "body", None)
     match status_code:
         case 401:
             raise AuthenticationError(
@@ -2366,6 +2367,7 @@ def _map_exception_by_status(
                 model=model,
                 llm_provider=custom_llm_provider,
                 response=response,
+                body=body,
                 litellm_debug_info=extra_information,
             )
         case 500:
@@ -2414,6 +2416,7 @@ def _map_exception_by_status(
                 model=model,
                 llm_provider=custom_llm_provider,
                 response=response,
+                body=body,
                 litellm_debug_info=extra_information,
             )
         case _:

litellm/llms/custom_httpx/llm_http_handler.py

@@ -4,7 +4,7 @@ import inspect
 import json
 import ssl
 from collections.abc import AsyncGenerator, AsyncIterator, Awaitable, Callable, Coroutine, Iterator, Mapping, Sequence
-from contextlib import asynccontextmanager
+from contextlib import asynccontextmanager, suppress
 from functools import lru_cache, partial, reduce
 from itertools import chain
 from types import MappingProxyType
@@ -573,6 +573,14 @@ def _unwrap_provider_error(error: Exception) -> Exception:
     return error
 
 
+def _parse_error_body(text: object) -> object | None:
+    if not isinstance(text, str) or not text.strip().startswith(("{", "[")):
+        return None
+    with suppress(json.JSONDecodeError, ValueError):
+        return json.loads(text)
+    return None
+
+
 def _merge_messages_header_sources(*sources: Mapping[str, object] | None) -> Mapping[str, object]:
     """Later sources win per header, except ``anthropic-beta``, which unions every source so client betas
     never drop a deployment's configured ones."""
@@ -6689,11 +6697,15 @@ class BaseLLMHTTPHandler:
         else:
             error_headers = {}
 
+        parsed_body: Final = _parse_error_body(error_text)
+
         if provider_config is None:
             raise BaseLLMException(
                 status_code=status_code,
                 message=error_text,
                 headers=error_headers,
+                response=error_response if isinstance(error_response, httpx.Response) else None,
+                body=parsed_body,
                 status_code_is_synthesized=not isinstance(received_status_code, int),
             )
 
@@ -6702,6 +6714,11 @@ class BaseLLMHTTPHandler:
             status_code=status_code,
             headers=error_headers,
         )
+        if isinstance(provider_error, BaseLLMException):
+            if isinstance(error_response, httpx.Response):
+                provider_error.response = error_response
+            if isinstance(parsed_body, dict) and provider_error.body is None:
+                provider_error.body = parsed_body
         if not isinstance(received_status_code, int):
             provider_error.status_code_is_synthesized = True
         raise provider_error

tests/unit/decisions/test_main.py

@@ -761,18 +761,42 @@ async def test_invalid_question_is_rejected_before_http(respx_mock: respx.MockRo
 
 
 def test_upstream_bad_request_maps_to_litellm_error(respx_mock: respx.MockRouter) -> None:
+    error_payload: Final = {"error": {"message": "invalid decision"}}
     respx_mock.post("https://api.perplexity.ai/v1/decisions").respond(
         status_code=400,
-        json={"error": {"message": "invalid decision"}},
+        json=error_payload,
     )
 
-    with pytest.raises(litellm.BadRequestError):
+    with pytest.raises(litellm.BadRequestError) as exc_info:
         litellm.systemone(
             model="perplexity/pplx-decider-v1-27b",
             state="review",
             questions={"is_defect": {"type": "noul", "instructions": "Is this a defect?"}},
             api_key="caller-key",
         )
+    assert exc_info.value.body == error_payload
+    assert exc_info.value.response is not None
+    assert json.loads(exc_info.value.response.text) == error_payload
+
+
+async def test_decisions_upstream_error_preserves_body_and_response(respx_mock: respx.MockRouter) -> None:
+    error_payload: Final = {"detail": {"error_type": "api_usage_error", "message": "Unknown model: jev-9"}}
+    respx_mock.post("https://api.typesafe.ai/v1/systemone").respond(
+        status_code=400,
+        json=error_payload,
+    )
+
+    with pytest.raises(litellm.BadRequestError) as exc_info:
+        await litellm.asystemone(
+            model="typesafe/jev-1.13.0",
+            state={"finding": "x"},
+            questions={"exp": {"type": "noul", "instructions": "Is it exploitable?"}},
+            api_key="sk-test",
+        )
+    assert exc_info.value.status_code == 400
+    assert exc_info.value.body == error_payload
+    assert exc_info.value.response is not None
+    assert json.loads(exc_info.value.response.text) == error_payload
 
 
 def test_unreachable_upstream_maps_to_a_connection_error(respx_mock: respx.MockRouter) -> None: