From c1132d045470853a8a186d730678493f3f015dbe Mon Sep 17 00:00:00 2001
From: shotsan <shotsan@users.noreply.github.com>
Date: Tue, 8 Sep 2026 13:44:50 -0700
Subject: [PATCH 1/7] fix(convert_dict_to_response): handle empty choices list
 without raising 500 APIError (Fixes #40276)

---
 .../convert_dict_to_response.py               |  6 +-
 .../test_convert_dict_to_response.py          | 70 ++++++++++++++++++-
 2 files changed, 72 insertions(+), 4 deletions(-)

diff --git a/litellm/litellm_core_utils/llm_response_utils/convert_dict_to_response.py b/litellm/litellm_core_utils/llm_response_utils/convert_dict_to_response.py
index a6f10e1ede3..7d8072ba622 100644
--- a/litellm/litellm_core_utils/llm_response_utils/convert_dict_to_response.py
+++ b/litellm/litellm_core_utils/llm_response_utils/convert_dict_to_response.py
@@ -179,7 +179,7 @@ async def convert_to_streaming_response_async(
 
     choice_list: Final[list[StreamingChoices]] = []
 
-    if not response_object.get("choices"):
+    if "choices" not in response_object or not isinstance(response_object["choices"], Iterable):
         from litellm.exceptions import APIError
 
         raise APIError(
@@ -287,7 +287,7 @@ def convert_to_streaming_response(
     model_response_object: Final = ModelResponseStream()
     choice_list: Final[list[StreamingChoices]] = []
 
-    if not response_object.get("choices"):
+    if "choices" not in response_object or not isinstance(response_object["choices"], Iterable):
         from litellm.exceptions import APIError
 
         raise APIError(
@@ -623,7 +623,7 @@ def convert_to_model_response_object(
                 return convert_to_streaming_response(response_object=response_object)
             choice_list: Final[list[Choices]] = []
 
-            if not response_object.get("choices") or not isinstance(response_object["choices"], Iterable):
+            if "choices" not in response_object or not isinstance(response_object["choices"], Iterable):
                 from litellm.exceptions import APIError
 
                 raise APIError(
diff --git a/tests/test_litellm/litellm_core_utils/llm_response_utils/test_convert_dict_to_response.py b/tests/test_litellm/litellm_core_utils/llm_response_utils/test_convert_dict_to_response.py
index 304d732c518..5406df691aa 100644
--- a/tests/test_litellm/litellm_core_utils/llm_response_utils/test_convert_dict_to_response.py
+++ b/tests/test_litellm/litellm_core_utils/llm_response_utils/test_convert_dict_to_response.py
@@ -1,4 +1,4 @@
-
+import pytest
 
 from litellm.constants import RESPONSE_FORMAT_TOOL_NAME
 from litellm.litellm_core_utils.llm_response_utils.convert_dict_to_response import (
@@ -99,3 +99,71 @@ def test_handle_invalid_parallel_tool_calls_skips_custom_tool_calls():
     )
     result = _handle_invalid_parallel_tool_calls([custom_tool_call, function_tool_call])
     assert result == [custom_tool_call, function_tool_call]
+
+
+def test_convert_empty_choices_response() -> None:
+    from litellm.litellm_core_utils.llm_response_utils.convert_dict_to_response import (
+        convert_to_streaming_response,
+    )
+
+    resp = {
+        "id": "x",
+        "created": 1,
+        "model": "gemini-3.5-flash",
+        "object": "chat.completion",
+        "choices": [],
+        "usage": {"prompt_tokens": 10, "completion_tokens": 0, "total_tokens": 10},
+        "vertex_ai_safety_results": ["blocked"],
+    }
+    result = convert_to_model_response_object(
+        response_object=resp,
+        model_response_object=ModelResponse(),
+        response_type="completion",
+    )
+    assert result.choices == []
+    assert getattr(result, "vertex_ai_safety_results") == ["blocked"]
+
+    # Test sync streaming generator handles empty choices
+    sync_stream = list(convert_to_streaming_response(response_object=resp))
+    assert len(sync_stream) == 1
+    assert sync_stream[0].choices == []
+
+
+@pytest.mark.asyncio
+async def test_convert_empty_choices_response_async() -> None:
+    from litellm.litellm_core_utils.llm_response_utils.convert_dict_to_response import (
+        convert_to_streaming_response_async,
+    )
+
+    resp = {
+        "id": "x",
+        "created": 1,
+        "model": "gemini-3.5-flash",
+        "object": "chat.completion",
+        "choices": [],
+        "usage": {"prompt_tokens": 10, "completion_tokens": 0, "total_tokens": 10},
+    }
+    async_chunks = []
+    async for chunk in convert_to_streaming_response_async(response_object=resp):
+        async_chunks.append(chunk)
+    assert len(async_chunks) == 1
+    assert async_chunks[0].choices == []
+
+
+def test_convert_missing_choices_raises_api_error() -> None:
+    from litellm.exceptions import APIError
+
+    resp = {
+        "id": "x",
+        "created": 1,
+        "model": "gemini-3.5-flash",
+        "object": "chat.completion",
+    }
+    with pytest.raises(APIError) as exc_info:
+        convert_to_model_response_object(
+            response_object=resp,
+            model_response_object=ModelResponse(),
+            response_type="completion",
+        )
+    assert "no 'choices'" in str(exc_info.value)
+

From 35def27e7b145c7aef7463bef34db4e56a2e8d9b Mon Sep 17 00:00:00 2001
From: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
Date: Wed, 9 Sep 2026 12:37:29 -0700
Subject: [PATCH 2/7] fix(convert_dict_to_response): accept only a real list as
 choices and keep /v1/messages alive on an empty one

Narrows the no-choices guard so a dict, string, or None still raises the APIError while an empty list passes through,
guards the non-stream Anthropic bridge against indexing an empty choices list, and repairs test_completion_missing_role,
whose raw-response mock was patched in as the create() callable itself so the handler only ever saw a MagicMock
---
 .../convert_dict_to_response.py               |  8 ++---
 .../adapters/transformation.py                |  3 +-
 .../test_convert_dict_to_response.py          | 30 +++++++++++++++++++
 ...al_pass_through_adapters_transformation.py | 15 ++++++++++
 tests/test_litellm/test_main.py               |  2 +-
 5 files changed, 52 insertions(+), 6 deletions(-)

diff --git a/litellm/litellm_core_utils/llm_response_utils/convert_dict_to_response.py b/litellm/litellm_core_utils/llm_response_utils/convert_dict_to_response.py
index 7d8072ba622..29b75812bfb 100644
--- a/litellm/litellm_core_utils/llm_response_utils/convert_dict_to_response.py
+++ b/litellm/litellm_core_utils/llm_response_utils/convert_dict_to_response.py
@@ -3,7 +3,7 @@ import json
 import re
 import time
 import traceback
-from collections.abc import Iterable, Sequence
+from collections.abc import Sequence
 from typing import Final, Literal, cast
 
 import litellm
@@ -179,7 +179,7 @@ async def convert_to_streaming_response_async(
 
     choice_list: Final[list[StreamingChoices]] = []
 
-    if "choices" not in response_object or not isinstance(response_object["choices"], Iterable):
+    if not isinstance(response_object.get("choices"), list):
         from litellm.exceptions import APIError
 
         raise APIError(
@@ -287,7 +287,7 @@ def convert_to_streaming_response(
     model_response_object: Final = ModelResponseStream()
     choice_list: Final[list[StreamingChoices]] = []
 
-    if "choices" not in response_object or not isinstance(response_object["choices"], Iterable):
+    if not isinstance(response_object.get("choices"), list):
         from litellm.exceptions import APIError
 
         raise APIError(
@@ -623,7 +623,7 @@ def convert_to_model_response_object(
                 return convert_to_streaming_response(response_object=response_object)
             choice_list: Final[list[Choices]] = []
 
-            if "choices" not in response_object or not isinstance(response_object["choices"], Iterable):
+            if not isinstance(response_object.get("choices"), list):
                 from litellm.exceptions import APIError
 
                 raise APIError(
diff --git a/litellm/llms/anthropic/experimental_pass_through/adapters/transformation.py b/litellm/llms/anthropic/experimental_pass_through/adapters/transformation.py
index db890662132..4bce760e943 100644
--- a/litellm/llms/anthropic/experimental_pass_through/adapters/transformation.py
+++ b/litellm/llms/anthropic/experimental_pass_through/adapters/transformation.py
@@ -1487,8 +1487,9 @@ class LiteLLMAnthropicMessagesAdapter:
             anthropic_content.insert(0, polyfill_result.compaction_block)
 
         ## extract finish reason
+        openai_finish_reason: Final = response.choices[0].finish_reason if response.choices else "stop"
         translated_finish_reason: Final = self._translate_openai_finish_reason_to_anthropic(
-            openai_finish_reason=response.choices[0].finish_reason
+            openai_finish_reason=openai_finish_reason
         )
         anthropic_finish_reason: Final = (
             "refusal"
diff --git a/tests/test_litellm/litellm_core_utils/llm_response_utils/test_convert_dict_to_response.py b/tests/test_litellm/litellm_core_utils/llm_response_utils/test_convert_dict_to_response.py
index 5406df691aa..ea50bff462e 100644
--- a/tests/test_litellm/litellm_core_utils/llm_response_utils/test_convert_dict_to_response.py
+++ b/tests/test_litellm/litellm_core_utils/llm_response_utils/test_convert_dict_to_response.py
@@ -1,3 +1,5 @@
+from typing import Final
+
 import pytest
 
 from litellm.constants import RESPONSE_FORMAT_TOOL_NAME
@@ -167,3 +169,31 @@ def test_convert_missing_choices_raises_api_error() -> None:
         )
     assert "no 'choices'" in str(exc_info.value)
 
+
+@pytest.mark.parametrize("choices", [{}, "", None, 0])
+@pytest.mark.asyncio
+async def test_convert_non_list_choices_raises_api_error(choices: object) -> None:
+    from litellm.exceptions import APIError
+    from litellm.litellm_core_utils.llm_response_utils.convert_dict_to_response import (
+        convert_to_streaming_response,
+        convert_to_streaming_response_async,
+    )
+
+    resp: Final = {
+        "id": "x",
+        "created": 1,
+        "model": "gemini-3.5-flash",
+        "object": "chat.completion",
+        "choices": choices,
+    }
+    with pytest.raises(APIError, match="no 'choices'"):
+        convert_to_model_response_object(
+            response_object=resp,
+            model_response_object=ModelResponse(),
+            response_type="completion",
+        )
+    with pytest.raises(APIError, match="no 'choices'"):
+        list(convert_to_streaming_response(response_object=resp))
+    with pytest.raises(APIError, match="no 'choices'"):
+        async for _ in convert_to_streaming_response_async(response_object=resp):
+            pass
diff --git a/tests/test_litellm/llms/anthropic/experimental_pass_through/adapters/test_anthropic_experimental_pass_through_adapters_transformation.py b/tests/test_litellm/llms/anthropic/experimental_pass_through/adapters/test_anthropic_experimental_pass_through_adapters_transformation.py
index c59ec70b015..00b3a0633f2 100644
--- a/tests/test_litellm/llms/anthropic/experimental_pass_through/adapters/test_anthropic_experimental_pass_through_adapters_transformation.py
+++ b/tests/test_litellm/llms/anthropic/experimental_pass_through/adapters/test_anthropic_experimental_pass_through_adapters_transformation.py
@@ -41,6 +41,21 @@ from litellm.types.utils import (
 )
 
 
+def test_translate_openai_response_to_anthropic_empty_choices() -> None:
+    response: Final = ModelResponse(
+        id="chatcmpl-empty",
+        model="gemini-3.5-flash",
+        choices=[],
+        usage=Usage(prompt_tokens=10, completion_tokens=0, total_tokens=10),
+    )
+
+    result: Final = LiteLLMAnthropicMessagesAdapter().translate_openai_response_to_anthropic(response)
+
+    assert result["content"] == []
+    assert result["stop_reason"] == "end_turn"
+    assert result["usage"]["input_tokens"] == 10
+
+
 def test_translate_chat_refusal_to_anthropic_response():
     response = ModelResponse(
         id="chatcmpl-refusal",
diff --git a/tests/test_litellm/test_main.py b/tests/test_litellm/test_main.py
index 038df3656fe..de6322f27ee 100644
--- a/tests/test_litellm/test_main.py
+++ b/tests/test_litellm/test_main.py
@@ -120,7 +120,7 @@ def test_completion_missing_role(openai_api_response):
     print(f"openai_api_response: {openai_api_response}")
 
     with patch.object(
-        client.chat.completions.with_raw_response, "create", mock_raw_response
+        client.chat.completions.with_raw_response, "create", MagicMock(return_value=mock_raw_response)
     ) as mock_create:
         litellm.completion(
             model="gpt-4o-mini",

From 17ca562b6a5d208d1b41a58933491936d4cefee2 Mon Sep 17 00:00:00 2001
From: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
Date: Wed, 9 Sep 2026 13:01:11 -0700
Subject: [PATCH 3/7] test(llm_translation): expect an empty choices list to
 convert instead of raising

---
 .../test_convert_dict_to_chat_completion.py   | 23 ++++++++-----------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/tests/llm_translation/test_llm_response_utils/test_convert_dict_to_chat_completion.py b/tests/llm_translation/test_llm_response_utils/test_convert_dict_to_chat_completion.py
index b6e30ddc711..09d1adba17c 100644
--- a/tests/llm_translation/test_llm_response_utils/test_convert_dict_to_chat_completion.py
+++ b/tests/llm_translation/test_llm_response_utils/test_convert_dict_to_chat_completion.py
@@ -1623,15 +1623,11 @@ class TestMissingChoicesGuard:
 
         assert "no 'choices'" in exc_info.value.message
 
-    def test_convert_to_model_response_object_empty_choices_raises_api_error(self):
-        """Empty choices list raises APIError, same as missing/null choices.
+    def test_convert_to_model_response_object_empty_choices_returns_empty_list(self):
+        """An empty choices list is a real provider answer, so it converts to choices=[] instead of raising.
 
-        Provider-specific repair (e.g. github_copilot synthesizing choices for
-        Anthropic-native responses) happens before this guard, in the provider
-        config; the core utility keeps treating empty choices as an error.
+        See: https://github.com/BerriAI/litellm/issues/40276
         """
-        from litellm.exceptions import APIError
-
         response_object = {
             "id": "msg_123",
             "model": "some-model",
@@ -1639,13 +1635,14 @@ class TestMissingChoicesGuard:
             "usage": {"prompt_tokens": 10, "completion_tokens": 1, "total_tokens": 11},
         }
 
-        with pytest.raises(APIError) as exc_info:
-            convert_to_model_response_object(
-                response_object=response_object,
-                model_response_object=ModelResponse(),
-            )
+        result = convert_to_model_response_object(
+            response_object=response_object,
+            model_response_object=ModelResponse(),
+        )
 
-        assert "no 'choices'" in exc_info.value.message
+        assert isinstance(result, ModelResponse)
+        assert result.choices == []
+        assert result.usage.prompt_tokens == 10
 
     def test_convert_to_model_response_object_null_choices_raises_api_error(self):
         """choices=None raises APIError."""

From f3a2844080f5b2dd003a084eece2861e78a1870d Mon Sep 17 00:00:00 2001
From: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
Date: Wed, 9 Sep 2026 13:05:11 -0700
Subject: [PATCH 4/7] test(convert_dict_to_response): keep the regression test
 locals final and comment-free

---
 .../test_convert_dict_to_response.py              | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/tests/test_litellm/litellm_core_utils/llm_response_utils/test_convert_dict_to_response.py b/tests/test_litellm/litellm_core_utils/llm_response_utils/test_convert_dict_to_response.py
index ea50bff462e..c3e99f01cec 100644
--- a/tests/test_litellm/litellm_core_utils/llm_response_utils/test_convert_dict_to_response.py
+++ b/tests/test_litellm/litellm_core_utils/llm_response_utils/test_convert_dict_to_response.py
@@ -108,7 +108,7 @@ def test_convert_empty_choices_response() -> None:
         convert_to_streaming_response,
     )
 
-    resp = {
+    resp: Final = {
         "id": "x",
         "created": 1,
         "model": "gemini-3.5-flash",
@@ -117,7 +117,7 @@ def test_convert_empty_choices_response() -> None:
         "usage": {"prompt_tokens": 10, "completion_tokens": 0, "total_tokens": 10},
         "vertex_ai_safety_results": ["blocked"],
     }
-    result = convert_to_model_response_object(
+    result: Final = convert_to_model_response_object(
         response_object=resp,
         model_response_object=ModelResponse(),
         response_type="completion",
@@ -125,8 +125,7 @@ def test_convert_empty_choices_response() -> None:
     assert result.choices == []
     assert getattr(result, "vertex_ai_safety_results") == ["blocked"]
 
-    # Test sync streaming generator handles empty choices
-    sync_stream = list(convert_to_streaming_response(response_object=resp))
+    sync_stream: Final = list(convert_to_streaming_response(response_object=resp))
     assert len(sync_stream) == 1
     assert sync_stream[0].choices == []
 
@@ -137,7 +136,7 @@ async def test_convert_empty_choices_response_async() -> None:
         convert_to_streaming_response_async,
     )
 
-    resp = {
+    resp: Final = {
         "id": "x",
         "created": 1,
         "model": "gemini-3.5-flash",
@@ -145,9 +144,7 @@ async def test_convert_empty_choices_response_async() -> None:
         "choices": [],
         "usage": {"prompt_tokens": 10, "completion_tokens": 0, "total_tokens": 10},
     }
-    async_chunks = []
-    async for chunk in convert_to_streaming_response_async(response_object=resp):
-        async_chunks.append(chunk)
+    async_chunks: Final = [chunk async for chunk in convert_to_streaming_response_async(response_object=resp)]
     assert len(async_chunks) == 1
     assert async_chunks[0].choices == []
 
@@ -155,7 +152,7 @@ async def test_convert_empty_choices_response_async() -> None:
 def test_convert_missing_choices_raises_api_error() -> None:
     from litellm.exceptions import APIError
 
-    resp = {
+    resp: Final = {
         "id": "x",
         "created": 1,
         "model": "gemini-3.5-flash",

From 29af8b734913f5e43e4149bcdcc36a7c9261cc37 Mon Sep 17 00:00:00 2001
From: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
Date: Wed, 9 Sep 2026 14:04:54 -0700
Subject: [PATCH 5/7] fix(streaming_handler): replay a cached completion with
 no choices as an empty stream

A stream cache hit on an entry stored with choices == [] indexed choices[0]
in the cached_response branch and failed with IndexError, so the streaming
converters' empty chunk had no working consumer. The branch now treats a
chunk without choices as empty and lets the wrapper close the stream with
its usual finish_reason stop chunk
---
 .../litellm_core_utils/streaming_handler.py   | 11 ++---
 .../test_streaming_handler.py                 | 43 ++++++++++++++++++-
 2 files changed, 46 insertions(+), 8 deletions(-)

diff --git a/litellm/litellm_core_utils/streaming_handler.py b/litellm/litellm_core_utils/streaming_handler.py
index 6ae17bac6ff..db23929e0c3 100644
--- a/litellm/litellm_core_utils/streaming_handler.py
+++ b/litellm/litellm_core_utils/streaming_handler.py
@@ -1473,17 +1473,14 @@ class CustomStreamWrapper:
                 self.received_finish_reason = response_obj["finish_reason"]
         elif self.custom_llm_provider == "cached_response":
             cached_chunk: Final = cast(ModelResponseStream, chunk)
-            chunk_finish_reason: Final = cached_chunk.choices[0].finish_reason
+            cached_choice: Final = cached_chunk.choices[0] if cached_chunk.choices else None
+            chunk_finish_reason: Final = cached_choice.finish_reason if cached_choice is not None else None
             response_obj = {
-                "text": cached_chunk.choices[0].delta.content,
+                "text": cached_choice.delta.content if cached_choice is not None else None,
                 "is_finished": chunk_finish_reason is not None,
                 "finish_reason": chunk_finish_reason,
                 "original_chunk": cached_chunk,
-                "tool_calls": (
-                    cached_chunk.choices[0].delta.tool_calls
-                    if hasattr(cached_chunk.choices[0].delta, "tool_calls")
-                    else None
-                ),
+                "tool_calls": (getattr(cached_choice.delta, "tool_calls", None) if cached_choice is not None else None),
             }
 
             completion_obj["content"] = response_obj["text"]
diff --git a/tests/test_litellm/litellm_core_utils/test_streaming_handler.py b/tests/test_litellm/litellm_core_utils/test_streaming_handler.py
index 0aa73833677..ced7d6d677d 100644
--- a/tests/test_litellm/litellm_core_utils/test_streaming_handler.py
+++ b/tests/test_litellm/litellm_core_utils/test_streaming_handler.py
@@ -6,7 +6,7 @@ import pytest
 
 import asyncio
 import traceback
-from typing import Optional
+from typing import Final, Optional
 
 import litellm
 from litellm import verbose_logger
@@ -2633,6 +2633,47 @@ def test_dispatch_cached_response_extracts_delta(
     assert initialized_custom_stream_wrapper.response_id == "chatcmpl-cache-1"
 
 
+def test_dispatch_cached_response_without_choices_is_an_empty_chunk(
+    initialized_custom_stream_wrapper: CustomStreamWrapper,
+):
+    """A cached completion with no choices replays as an empty, unfinished chunk
+    instead of raising IndexError on choices[0]."""
+    initialized_custom_stream_wrapper.custom_llm_provider = "cached_response"
+    chunk: Final = ModelResponseStream(id="chatcmpl-cache-empty", choices=[])
+
+    result, model_response, completion_obj = _run_dispatch(
+        initialized_custom_stream_wrapper, chunk
+    )
+
+    assert isinstance(result, _ProviderChunkParsed)
+    assert completion_obj["content"] is None
+    assert initialized_custom_stream_wrapper.received_finish_reason is None
+    assert model_response.id == "chatcmpl-cache-empty"
+
+
+@pytest.mark.asyncio
+async def test_cached_response_without_choices_streams_a_single_stop_chunk(
+    logging_obj: Logging,
+):
+    """A stream cache hit on a completion stored with choices == [] ends with one
+    finish_reason=stop chunk, the same shape the live empty stream produced."""
+
+    async def cached_chunks():
+        yield ModelResponseStream(id="chatcmpl-cache-empty", choices=[])
+
+    wrapper: Final = CustomStreamWrapper(
+        completion_stream=cached_chunks(),
+        model="test-model",
+        logging_obj=logging_obj,
+        custom_llm_provider="cached_response",
+    )
+
+    chunks: Final = tuple([chunk async for chunk in wrapper])
+
+    assert tuple(choice.finish_reason for chunk in chunks for choice in chunk.choices) == ("stop",)
+    assert all(choice.delta.content in (None, "") for chunk in chunks for choice in chunk.choices)
+
+
 def test_dispatch_vertex_ai_legacy_text_and_finish_reason(
     initialized_custom_stream_wrapper: CustomStreamWrapper,
 ):

From cbeac276561c82e71f56de6d76e4d132170a2cc6 Mon Sep 17 00:00:00 2001
From: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
Date: Wed, 9 Sep 2026 15:12:13 -0700
Subject: [PATCH 6/7] fix(convert_dict_to_response): name the non-list choices
 type in the converter error

When a provider returns choices as null, an object, a string or a number, the
converter said the response had no 'choices' even though the key was present in
the raw keys it listed. A shared message now keeps the old wording for a missing
key and names the offending type otherwise.

The cached-stream regression test also pins the chunk count so a leaked extra
chunk fails it.
---
 .../convert_dict_to_response.py               | 25 +++++++++++--------
 .../test_convert_dict_to_response.py          | 11 ++++----
 .../test_streaming_handler.py                 |  1 +
 3 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/litellm/litellm_core_utils/llm_response_utils/convert_dict_to_response.py b/litellm/litellm_core_utils/llm_response_utils/convert_dict_to_response.py
index 29b75812bfb..87524d86c61 100644
--- a/litellm/litellm_core_utils/llm_response_utils/convert_dict_to_response.py
+++ b/litellm/litellm_core_utils/llm_response_utils/convert_dict_to_response.py
@@ -3,7 +3,7 @@ import json
 import re
 import time
 import traceback
-from collections.abc import Sequence
+from collections.abc import Mapping, Sequence
 from typing import Final, Literal, cast
 
 import litellm
@@ -151,6 +151,16 @@ def _clear_later_replay_slice_metadata(choice: StreamingChoices) -> None:
         del choice.enhancements
 
 
+def _invalid_choices_message(response_object: Mapping[str, object]) -> str:
+    raw_keys: Final = list(response_object.keys())
+    if "choices" not in response_object:
+        return f"LiteLLM: provider returned a response with no 'choices'. Raw keys: {raw_keys}"
+    return (
+        f"LiteLLM: provider returned 'choices' that is not a list ({type(response_object['choices']).__name__}). "
+        f"Raw keys: {raw_keys}"
+    )
+
+
 async def convert_to_streaming_response_async(
     response_object: dict | None = None,
 ):
@@ -184,9 +194,7 @@ async def convert_to_streaming_response_async(
 
         raise APIError(
             status_code=500,
-            message=(
-                f"LiteLLM: provider returned a response with no 'choices'. Raw keys: {list(response_object.keys())}"
-            ),
+            message=_invalid_choices_message(response_object),
             llm_provider="",
             model="",
         )
@@ -292,9 +300,7 @@ def convert_to_streaming_response(
 
         raise APIError(
             status_code=500,
-            message=(
-                f"LiteLLM: provider returned a response with no 'choices'. Raw keys: {list(response_object.keys())}"
-            ),
+            message=_invalid_choices_message(response_object),
             llm_provider="",
             model="",
         )
@@ -628,10 +634,7 @@ def convert_to_model_response_object(
 
                 raise APIError(
                     status_code=500,
-                    message=(
-                        "LiteLLM: provider returned a response with no 'choices'. "
-                        f"Raw keys: {list(response_object.keys())}"
-                    ),
+                    message=_invalid_choices_message(response_object),
                     llm_provider="",
                     model="",
                 )
diff --git a/tests/test_litellm/litellm_core_utils/llm_response_utils/test_convert_dict_to_response.py b/tests/test_litellm/litellm_core_utils/llm_response_utils/test_convert_dict_to_response.py
index c3e99f01cec..8e46ae21de6 100644
--- a/tests/test_litellm/litellm_core_utils/llm_response_utils/test_convert_dict_to_response.py
+++ b/tests/test_litellm/litellm_core_utils/llm_response_utils/test_convert_dict_to_response.py
@@ -167,9 +167,9 @@ def test_convert_missing_choices_raises_api_error() -> None:
     assert "no 'choices'" in str(exc_info.value)
 
 
-@pytest.mark.parametrize("choices", [{}, "", None, 0])
+@pytest.mark.parametrize(("choices", "type_name"), [({}, "dict"), ("", "str"), (None, "NoneType"), (0, "int")])
 @pytest.mark.asyncio
-async def test_convert_non_list_choices_raises_api_error(choices: object) -> None:
+async def test_convert_non_list_choices_raises_api_error(choices: object, type_name: str) -> None:
     from litellm.exceptions import APIError
     from litellm.litellm_core_utils.llm_response_utils.convert_dict_to_response import (
         convert_to_streaming_response,
@@ -183,14 +183,15 @@ async def test_convert_non_list_choices_raises_api_error(choices: object) -> Non
         "object": "chat.completion",
         "choices": choices,
     }
-    with pytest.raises(APIError, match="no 'choices'"):
+    expected: Final = f"'choices' that is not a list \\({type_name}\\)"
+    with pytest.raises(APIError, match=expected):
         convert_to_model_response_object(
             response_object=resp,
             model_response_object=ModelResponse(),
             response_type="completion",
         )
-    with pytest.raises(APIError, match="no 'choices'"):
+    with pytest.raises(APIError, match=expected):
         list(convert_to_streaming_response(response_object=resp))
-    with pytest.raises(APIError, match="no 'choices'"):
+    with pytest.raises(APIError, match=expected):
         async for _ in convert_to_streaming_response_async(response_object=resp):
             pass
diff --git a/tests/test_litellm/litellm_core_utils/test_streaming_handler.py b/tests/test_litellm/litellm_core_utils/test_streaming_handler.py
index ced7d6d677d..37e2031fdf4 100644
--- a/tests/test_litellm/litellm_core_utils/test_streaming_handler.py
+++ b/tests/test_litellm/litellm_core_utils/test_streaming_handler.py
@@ -2670,6 +2670,7 @@ async def test_cached_response_without_choices_streams_a_single_stop_chunk(
 
     chunks: Final = tuple([chunk async for chunk in wrapper])
 
+    assert len(chunks) == 1
     assert tuple(choice.finish_reason for chunk in chunks for choice in chunk.choices) == ("stop",)
     assert all(choice.delta.content in (None, "") for chunk in chunks for choice in chunk.choices)
 

From 21e6c6e2f3c9fe993925b6aaaca6314bd56b1add Mon Sep 17 00:00:00 2001
From: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
Date: Wed, 9 Sep 2026 15:56:41 -0700
Subject: [PATCH 7/7] test(convert_dict_to_response): expect the type-naming
 error for a null choices value

---
 .../test_convert_dict_to_chat_completion.py                   | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/llm_translation/test_llm_response_utils/test_convert_dict_to_chat_completion.py b/tests/llm_translation/test_llm_response_utils/test_convert_dict_to_chat_completion.py
index 09d1adba17c..31c554985a7 100644
--- a/tests/llm_translation/test_llm_response_utils/test_convert_dict_to_chat_completion.py
+++ b/tests/llm_translation/test_llm_response_utils/test_convert_dict_to_chat_completion.py
@@ -1645,7 +1645,7 @@ class TestMissingChoicesGuard:
         assert result.usage.prompt_tokens == 10
 
     def test_convert_to_model_response_object_null_choices_raises_api_error(self):
-        """choices=None raises APIError."""
+        """choices=None raises APIError that names the type instead of claiming the key is missing."""
         from litellm.exceptions import APIError
 
         response_object = {
@@ -1661,7 +1661,7 @@ class TestMissingChoicesGuard:
                 model_response_object=ModelResponse(),
             )
 
-        assert "no 'choices'" in exc_info.value.message
+        assert "'choices' that is not a list (NoneType)" in exc_info.value.message
 
     def test_convert_to_streaming_response_no_choices_raises_api_error(self):
         """Missing choices in streaming cache-hit path raises APIError."""