From ce02ebfbd03e95900f9c9ff1cffc3f16f350e7e4 Mon Sep 17 00:00:00 2001
From: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
Date: Tue, 3 Nov 2026 23:03:53 -0800
Subject: [PATCH] fix(bedrock): send only the effort from output_config to
 Converse Claude without thinking

Other output_config keys such as task_budget never reached Converse without a
thinking block, and Bedrock answers 400 to them, so they stay behind there
---
 .../messages/adapters/transformation.py       | 11 +++++---
 ...hropic_messages_adapters_transformation.py | 27 +++++++++++++++++++
 2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/litellm/llms/anthropic/messages/adapters/transformation.py b/litellm/llms/anthropic/messages/adapters/transformation.py
index 6743c4fd329..33e2abb4075 100644
--- a/litellm/llms/anthropic/messages/adapters/transformation.py
+++ b/litellm/llms/anthropic/messages/adapters/transformation.py
@@ -1222,7 +1222,9 @@ class LiteLLMAnthropicMessagesAdapter:
 
         Bedrock Converse takes the tier in ``output_config`` with or without a ``thinking`` block, so
         it travels on its own instead of only alongside ``thinking``. ``format`` stays behind, since
-        ``_translate_output_format_to_openai`` carries it as ``response_format``.
+        ``_translate_output_format_to_openai`` carries it as ``response_format``. Without ``thinking``
+        only ``effort`` goes, since the other keys (``task_budget``) never reached Converse there and
+        it rejects them.
         """
         if "output_config" not in anthropic_message_request or not self._is_bedrock_claude_target(new_kwargs["model"]):
             return
@@ -1231,13 +1233,16 @@ class LiteLLMAnthropicMessagesAdapter:
         if not isinstance(output_config, dict):
             return
 
-        effort_config: Final = {k: v for k, v in output_config.items() if k != "format"}
+        has_thinking: Final = bool(anthropic_message_request.get("thinking"))
+        effort_config: Final = {
+            k: v for k, v in output_config.items() if k == "effort" or (has_thinking and k != "format")
+        }
         if not effort_config:
             return
         model: Final = new_kwargs["model"]
         if (
             drop_params
-            and not anthropic_message_request.get("thinking")
+            and not has_thinking
             and is_bedrock_application_inference_profile_arn(bedrock_capability_model(model, base_model))
         ):
             litellm.verbose_logger.warning(UNRESOLVED_ARN_EFFORT_WITHOUT_THINKING_WARNING, model)
diff --git a/tests/unit/llms/anthropic/messages/adapters/test_anthropic_messages_adapters_transformation.py b/tests/unit/llms/anthropic/messages/adapters/test_anthropic_messages_adapters_transformation.py
index 05f6e61db0c..1e2dc5e44a2 100644
--- a/tests/unit/llms/anthropic/messages/adapters/test_anthropic_messages_adapters_transformation.py
+++ b/tests/unit/llms/anthropic/messages/adapters/test_anthropic_messages_adapters_transformation.py
@@ -5526,6 +5526,33 @@ async def test_bedrock_converse_claude_gets_the_effort_without_a_thinking_block(
     assert "thinking" not in sent
 
 
+_TASK_BUDGET: Final = {"type": "tokens", "total": 20000}
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    ("output_config", "sent_output_config"),
+    [
+        pytest.param({"effort": "low", "task_budget": _TASK_BUDGET}, {"effort": "low"}, id="effort_and_task_budget"),
+        pytest.param({"task_budget": _TASK_BUDGET}, None, id="task_budget_only"),
+    ],
+)
+async def test_bedrock_converse_claude_without_a_thinking_block_gets_only_the_effort_from_output_config(
+    _converse_route: respx.Route,
+    output_config: Mapping[str, object],
+    sent_output_config: Mapping[str, object] | None,
+) -> None:
+    await litellm.anthropic.messages.acreate(
+        model=f"bedrock/converse/{_CONVERSE_EFFORT_MODEL}",
+        max_tokens=64,
+        messages=[{"role": "user", "content": "Name the capital of France."}],
+        output_config=output_config,
+        drop_params=True,
+    )
+
+    assert _sent_converse_fields(_converse_route).get("output_config") == sent_output_config
+
+
 @pytest.mark.asyncio
 @pytest.mark.parametrize(
     ("drop_params_source", "forwards_effort"),