fix(databricks): accept Reasoning(effort=..., summary=...) dict for reasoning_effort

OpenAI Responses callers send reasoning_effort as a dict
({'effort': 'low', 'summary': 'concise'}) — the Responses->Chat parser keeps
the full dict when summary is set (#25359 / #28196). The Databricks Claude
adapter only handled the bare string and silently dropped the dict shape.
Coerce dict -> effort before mapping, matching the direct Anthropic and
Bedrock Converse adapters. Adds regression tests for both shapes.

litellm/llms/databricks/chat/transformation.py

@@ -358,7 +358,15 @@ class DatabricksConfig(DatabricksBase, OpenAILikeChatConfig, AnthropicConfig):
             )  # unsupported for claude models - if json_schema -> convert to tool call
 
         if "reasoning_effort" in non_default_params and "claude" in model:
-            reasoning_effort_value: Final = non_default_params.get("reasoning_effort")
+            reasoning_effort_value = non_default_params.get("reasoning_effort")
+            # Accept both string ("low") and dict ({"effort": "low",
+            # "summary": "concise"}). The Responses->Chat parser keeps the
+            # full dict when `summary` is set (see #25359 / #28196), so a
+            # dict here is the standard shape Otto/OpenAI-Responses-Bridge
+            # callers send. Same coercion the direct Anthropic adapter and
+            # the Bedrock Converse adapter already do.
+            if isinstance(reasoning_effort_value, dict):
+                reasoning_effort_value = reasoning_effort_value.get("effort")
             mapped_thinking: Final = AnthropicConfig._map_reasoning_effort(
                 reasoning_effort=reasoning_effort_value,
                 model=model,

tests/test_litellm/llms/databricks/chat/test_databricks_chat_transformation.py

@@ -1,9 +1,4 @@
-import json
-
 import pytest
-from fastapi.testclient import TestClient
-
-from unittest.mock import MagicMock, patch
 
 from litellm.llms.databricks.chat.transformation import (
     DatabricksChatResponseIterator,
@@ -493,3 +488,49 @@ def test_chunk_parser_without_usage_still_parses_content():
     assert result.id == "chatcmpl-test"
     assert result.model == "databricks-claude-sonnet-5"
     assert result.choices[0]["delta"]["content"] == "hi"
+
+
+@pytest.mark.parametrize(
+    "model",
+    [
+        "databricks/databricks-claude-3-7-sonnet",
+        "databricks/databricks-claude-opus-4-7",
+    ],
+)
+def test_reasoning_effort_accepts_dict_shape(model):
+    """Regression for #28196 (companion to bedrock + direct Anthropic fixes).
+
+    OpenAI Responses callers send
+    ``reasoning_effort={'effort': 'low', 'summary': 'concise'}``;
+    the Databricks Claude adapter must coerce the dict to ``low`` and
+    forward thinking + (for adaptive Claude 4.6 / 4.7) output_config,
+    instead of silently dropping it.
+    """
+    config = DatabricksConfig()
+
+    optional_params = config.map_openai_params(
+        non_default_params={
+            "reasoning_effort": {"effort": "low", "summary": "concise"},
+        },
+        optional_params={},
+        model=model,
+        drop_params=False,
+        replace_max_completion_tokens_with_max_tokens=False,
+    )
+
+    assert "thinking" in optional_params, f"reasoning_effort dict was dropped on {model}: {optional_params!r}"
+
+
+def test_reasoning_effort_bare_string_still_works():
+    """Regression guard for the pre-existing string shape."""
+    config = DatabricksConfig()
+
+    optional_params = config.map_openai_params(
+        non_default_params={"reasoning_effort": "low"},
+        optional_params={},
+        model="databricks/databricks-claude-3-7-sonnet",
+        drop_params=False,
+        replace_max_completion_tokens_with_max_tokens=False,
+    )
+
+    assert "thinking" in optional_params