From 330f36c5612580911aa1c86f15f03576ad017bd5 Mon Sep 17 00:00:00 2001
From: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Date: Sun, 25 Oct 2026 16:39:17 +0000
Subject: [PATCH 1/3] fix(router): handle moderation text batch inputs

---
 litellm/router.py                     |  8 ++++++++
 tests/unit/test_router/test_router.py | 14 ++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/litellm/router.py b/litellm/router.py
index 7993b5b921c..ec4705e6f14 100644
--- a/litellm/router.py
+++ b/litellm/router.py
@@ -14347,6 +14347,14 @@ class Router:
         from litellm.litellm_core_utils.prompt_templates.common_utils import request_contains_image_content
         from litellm.litellm_core_utils.prompt_templates.factory import resolve_structured_messages
 
+        input_data: Final = request_kwargs.get("input")
+        if (
+            not messages
+            and isinstance(input_data, list)
+            and all(isinstance(item, str) for item in cast(list[object], input_data))
+        ):
+            return False
+
         structured: Final = resolve_structured_messages(
             messages=cast(list[dict[str, object]] | None, messages),  # cast-ok: chat messages are plain dicts
             request_kwargs=cast(dict[str, object], request_kwargs),  # cast-ok: the resolver only reads the mapping
diff --git a/tests/unit/test_router/test_router.py b/tests/unit/test_router/test_router.py
index 568a05e8ff4..caeec3c135c 100644
--- a/tests/unit/test_router/test_router.py
+++ b/tests/unit/test_router/test_router.py
@@ -30099,6 +30099,20 @@ def test_image_routing_drop_declared_text_only_legs_for_responses_input_image():
     assert _candidate_ids(router, request_kwargs={"input": _IMAGE_RESPONSES_INPUT}) == ["vision"]
 
 
+@pytest.mark.parametrize(
+    ("messages", "expected"),
+    [(None, ("vision", "declared-text")), (_IMAGE_CHAT, ("vision",))],
+    ids=["text-batch", "image-messages-take-precedence"],
+)
+def test_image_routing_handles_text_batch_input_without_overriding_messages(
+    messages: list[dict[str, object]] | None, expected: tuple[str, ...]
+) -> None:
+    router: Final = _mixed_router(_VISION_LEG, _DECLARED_TEXT_LEG)
+    assert tuple(
+        _candidate_ids(router, messages=messages, request_kwargs={"input": ["safe text", "more safe text"]})
+    ) == expected
+
+
 def test_image_routing_send_image_to_the_group_when_every_leg_is_declared_text_only():
     other_text_leg = {**_DECLARED_TEXT_LEG, "model_info": {"id": "declared-text-2", "supports_vision": False}}
     router: Final = _mixed_router(_DECLARED_TEXT_LEG, other_text_leg)

From 4dbcdefc2dce3fd1e606426526b5e7c4a2e15654 Mon Sep 17 00:00:00 2001
From: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Date: Sun, 25 Oct 2026 17:01:47 +0000
Subject: [PATCH 2/3] fix(router): avoid unchecked cast in text batch check

---
 litellm/router.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/litellm/router.py b/litellm/router.py
index ec4705e6f14..1fc7ee3cb15 100644
--- a/litellm/router.py
+++ b/litellm/router.py
@@ -14351,7 +14351,7 @@ class Router:
         if (
             not messages
             and isinstance(input_data, list)
-            and all(isinstance(item, str) for item in cast(list[object], input_data))
+            and all(isinstance(item, str) for item in input_data)
         ):
             return False
 

From 3458e4aae1081d6d154fd5df8bd8ec3570455b14 Mon Sep 17 00:00:00 2001
From: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Date: Sun, 25 Oct 2026 17:27:57 +0000
Subject: [PATCH 3/3] fix(router): validate text batch without cast

---
 litellm/router.py | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/litellm/router.py b/litellm/router.py
index 1fc7ee3cb15..6c5d47467d0 100644
--- a/litellm/router.py
+++ b/litellm/router.py
@@ -610,6 +610,7 @@ _SESSION_ADAPTER: Final = TypeAdapter(Mapping[str, object])
 _MODEL_INFO_ADAPTER: Final = TypeAdapter(Mapping[str, object])
 _LITELLM_PARAMS_ADAPTER: Final = TypeAdapter(Mapping[str, object])
 _SILENT_MODEL_ADAPTER: Final = TypeAdapter(str | list[str])
+_TEXT_INPUT_BATCH_ADAPTER: Final = TypeAdapter(list[str])
 _RESOLVED_RETRY_POLICY_ADAPTER: Final = TypeAdapter(RetryPolicy | None)
 _ROUTING_KWARGS_ADAPTER: Final[TypeAdapter[Mapping[str, object] | None]] = TypeAdapter(Mapping[str, object] | None)
 _FALLBACK_HOP_ADAPTER: Final = TypeAdapter(Mapping[str, object])
@@ -14348,12 +14349,13 @@ class Router:
         from litellm.litellm_core_utils.prompt_templates.factory import resolve_structured_messages
 
         input_data: Final = request_kwargs.get("input")
-        if (
-            not messages
-            and isinstance(input_data, list)
-            and all(isinstance(item, str) for item in input_data)
-        ):
-            return False
+        if not messages:
+            try:
+                _TEXT_INPUT_BATCH_ADAPTER.validate_python(input_data, strict=True)
+            except ValidationError:
+                pass
+            else:
+                return False
 
         structured: Final = resolve_structured_messages(
             messages=cast(list[dict[str, object]] | None, messages),  # cast-ok: chat messages are plain dicts