diff --git a/litellm/litellm_core_utils/prompt_templates/common_utils.py b/litellm/litellm_core_utils/prompt_templates/common_utils.py
index 4ba7c3966c0..1e96e20a03b 100644
--- a/litellm/litellm_core_utils/prompt_templates/common_utils.py
+++ b/litellm/litellm_core_utils/prompt_templates/common_utils.py
@@ -2261,6 +2261,37 @@ def system_messages_first(
     ]
 
 
+def _system_content_as_text_parts(content: object) -> tuple[object, ...]:
+    if isinstance(content, str):
+        return (ChatCompletionTextObject(type="text", text=content),)
+    return tuple(cast(Sequence[object], content))  # cast-ok: non-str system content is a list of content parts
+
+
+def _merge_system_message_run(run: Sequence[AllMessageValues]) -> AllMessageValues:
+    if len(run) == 1:
+        return run[0]
+    contents: Final = tuple(content for content in (message.get("content") for message in run) if content is not None)
+    if not contents:
+        return run[0]
+    if all(isinstance(content, str) for content in contents):
+        joined_text: Final = "\n\n".join(cast(tuple[str, ...], contents))  # cast-ok: every content is a str
+        return cast(AllMessageValues, {**run[0], "content": joined_text})  # cast-ok: dict spread keeps message shape
+    merged_parts: Final = [  # mutable-ok: chat message content must stay a json list
+        part for content in contents for part in _system_content_as_text_parts(content)
+    ]
+    return cast(AllMessageValues, {**run[0], "content": merged_parts})  # cast-ok: dict spread keeps message shape
+
+
+def merge_consecutive_system_messages(
+    messages: list[AllMessageValues],  # mutable-ok: message pipelines type messages as mutable lists
+) -> list[AllMessageValues]:  # mutable-ok: message pipelines type messages as mutable lists
+    return [  # mutable-ok: pipelines mutate message lists
+        merged
+        for is_system_run, run in groupby(messages, key=lambda message: message.get("role") == "system")
+        for merged in ((_merge_system_message_run(tuple(run)),) if is_system_run else run)
+    ]
+
+
 def _attempt_json_repair(s: str) -> object | None:
     """
     Attempt to repair truncated JSON produced by LLM tool calls.
diff --git a/litellm/llms/databricks/chat/transformation.py b/litellm/llms/databricks/chat/transformation.py
index dd257cd68b0..30144d29f51 100644
--- a/litellm/llms/databricks/chat/transformation.py
+++ b/litellm/llms/databricks/chat/transformation.py
@@ -16,6 +16,7 @@ from litellm.litellm_core_utils.llm_response_utils.convert_dict_to_response impo
 )
 from litellm.litellm_core_utils.prompt_templates.common_utils import (
     _extract_reasoning_content,  # pyright: ignore[reportPrivateUsage]  # same import as the OpenAI transformation
+    merge_consecutive_system_messages,
     strip_litellm_internal_message_fields,
     strip_name_from_message,
 )
@@ -465,7 +466,9 @@ class DatabricksConfig(DatabricksBase, OpenAILikeChatConfig, AnthropicConfig):
             new_messages.append(_message)
 
         if "claude" not in model:
-            new_messages = _split_parallel_tool_calls(cast(list[AllMessageValues], new_messages))
+            new_messages = _split_parallel_tool_calls(
+                merge_consecutive_system_messages(cast(list[AllMessageValues], new_messages))
+            )
 
         if is_async:
             return super()._transform_messages(messages=new_messages, model=model, is_async=cast(Literal[True], True))
diff --git a/litellm/responses/main.py b/litellm/responses/main.py
index 5a4a08b760c..c5032536df4 100644
--- a/litellm/responses/main.py
+++ b/litellm/responses/main.py
@@ -433,13 +433,18 @@ def _bridges_to_chat_completions(
     return responses_api_provider_config is None or use_chat_completions_api is True
 
 
+_RESPONSES_ONLY_REQUEST_FIELDS_NEVER_BRIDGED: Final = frozenset({"client_metadata"})
+
+
 def _bridge_kwargs(
     kwargs: Mapping[str, object],
     responses_api_provider_config: BaseResponsesAPIConfig | None,
     allowed_openai_params: Sequence[str] | None,
 ) -> Mapping[str, object]:
     if responses_api_provider_config is None:
-        return kwargs
+        return MappingProxyType(
+            {key: value for key, value in kwargs.items() if key not in _RESPONSES_ONLY_REQUEST_FIELDS_NEVER_BRIDGED}
+        )
     forwarded_keys: Final = frozenset(
         (
             *litellm.OPENAI_CHAT_COMPLETION_PARAMS,
@@ -448,7 +453,7 @@ def _bridge_kwargs(
             *GenericLiteLLMParams.model_fields,
             *(allowed_openai_params or ()),
         )
-    )
+    ).difference(_RESPONSES_ONLY_REQUEST_FIELDS_NEVER_BRIDGED)
     return MappingProxyType({key: value for key, value in kwargs.items() if key in forwarded_keys})
 
 
diff --git a/tests/test_litellm/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_common_utils.py b/tests/test_litellm/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_common_utils.py
index c67f72680a8..62cf5680266 100644
--- a/tests/test_litellm/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_common_utils.py
+++ b/tests/test_litellm/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_common_utils.py
@@ -20,6 +20,7 @@ from litellm.litellm_core_utils.prompt_templates.common_utils import (
     handle_any_messages_to_chat_completion_str_messages_conversion,
     hoist_images_from_tool_messages,
     is_encrypted_reasoning_block,
+    merge_consecutive_system_messages,
     responses_reasoning_items_from_thinking_blocks,
     split_concatenated_json_objects,
     strip_encrypted_reasoning_from_messages,
@@ -1846,3 +1847,95 @@ class TestEncryptedReasoningReplay:
         strip_encrypted_reasoning_from_messages(messages)
 
         assert messages == before
+
+
+class TestMergeConsecutiveSystemMessages:
+    def test_merges_each_run_of_string_system_messages_with_a_blank_line(self):
+        messages = [
+            {"role": "system", "content": "You are terse.", "cache_control": {"type": "ephemeral"}},
+            {"role": "system", "content": "Skills: none."},
+            {"role": "user", "content": "Hello"},
+            {"role": "assistant", "content": "Hi"},
+            {"role": "system", "content": "Reminder A"},
+            {"role": "system", "content": "Reminder B"},
+            {"role": "user", "content": "Bye"},
+        ]
+
+        merged = merge_consecutive_system_messages(messages)
+
+        assert merged == [
+            {"role": "system", "content": "You are terse.\n\nSkills: none.", "cache_control": {"type": "ephemeral"}},
+            {"role": "user", "content": "Hello"},
+            {"role": "assistant", "content": "Hi"},
+            {"role": "system", "content": "Reminder A\n\nReminder B"},
+            {"role": "user", "content": "Bye"},
+        ]
+
+    def test_merges_into_text_parts_when_any_system_content_is_a_list(self):
+        cached_part = {"type": "text", "text": "Skills: none.", "cache_control": {"type": "ephemeral"}}
+        messages = [
+            {"role": "system", "content": "You are terse."},
+            {"role": "system", "content": [cached_part, {"type": "text", "text": "Be brief."}]},
+            {"role": "system", "content": "Answer in English."},
+            {"role": "user", "content": "Hello"},
+        ]
+
+        merged = merge_consecutive_system_messages(messages)
+
+        assert merged == [
+            {
+                "role": "system",
+                "content": [
+                    {"type": "text", "text": "You are terse."},
+                    cached_part,
+                    {"type": "text", "text": "Be brief."},
+                    {"type": "text", "text": "Answer in English."},
+                ],
+            },
+            {"role": "user", "content": "Hello"},
+        ]
+        assert merged[0]["content"][1] is cached_part
+
+    @pytest.mark.parametrize(
+        "messages",
+        [
+            [{"role": "system", "content": "You are terse."}, {"role": "user", "content": "Hello"}],
+            [{"role": "user", "content": "Hello"}, {"role": "assistant", "content": "Hi"}],
+            [
+                {"role": "system", "content": "You are terse."},
+                {"role": "user", "content": "Hello"},
+                {"role": "system", "content": "Reminder"},
+            ],
+            [],
+        ],
+        ids=["single-system", "no-system", "separated-systems", "empty"],
+    )
+    def test_leaves_messages_without_consecutive_system_messages_untouched(self, messages):
+        before = copy.deepcopy(messages)
+
+        merged = merge_consecutive_system_messages(messages)
+
+        assert merged == before
+        assert [message is original for message, original in zip(merged, messages)] == [True] * len(messages)
+
+    @pytest.mark.parametrize(
+        ("messages", "expected_content"),
+        [
+            ([{"role": "system"}, {"role": "system", "content": "Skills: none."}], "Skills: none."),
+            ([{"role": "system", "content": "You are terse."}, {"role": "system"}], "You are terse."),
+            (
+                [{"role": "system"}, {"role": "system", "content": [{"type": "text", "text": "Be brief."}]}],
+                [{"type": "text", "text": "Be brief."}],
+            ),
+        ],
+        ids=["missing-then-str", "str-then-missing", "missing-then-list"],
+    )
+    def test_skips_system_messages_without_content_when_merging(self, messages, expected_content):
+        merged = merge_consecutive_system_messages([*messages, {"role": "user", "content": "Hello"}])
+
+        assert merged == [{"role": "system", "content": expected_content}, {"role": "user", "content": "Hello"}]
+
+    def test_keeps_the_first_message_when_no_system_message_in_the_run_has_content(self):
+        merged = merge_consecutive_system_messages([{"role": "system"}, {"role": "system"}, {"role": "user", "content": "Hi"}])
+
+        assert merged == [{"role": "system"}, {"role": "user", "content": "Hi"}]
diff --git a/tests/test_litellm/llms/databricks/chat/__init__.py b/tests/test_litellm/llms/databricks/chat/__init__.py
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/tests/test_litellm/llms/databricks/chat/test_databricks_chat_transformation.py b/tests/test_litellm/llms/databricks/chat/test_databricks_chat_transformation.py
new file mode 100644
index 00000000000..a3391a2c585
--- /dev/null
+++ b/tests/test_litellm/llms/databricks/chat/test_databricks_chat_transformation.py
@@ -0,0 +1,79 @@
+import json
+from typing import Final
+
+import httpx
+import respx
+
+import litellm
+
+
+def test_completion_merges_leading_system_and_developer_messages_for_chat_template_models(
+    respx_mock: respx.MockRouter,
+):
+    upstream: Final = respx_mock.post("https://example.databricks.test/serving-endpoints/chat/completions").mock(
+        return_value=httpx.Response(
+            status_code=200,
+            json={
+                "id": "chatcmpl-123",
+                "object": "chat.completion",
+                "created": 1677652288,
+                "model": "my-custom-model",
+                "choices": [{"index": 0, "message": {"role": "assistant", "content": "Answer"}, "finish_reason": "stop"}],
+                "usage": {"prompt_tokens": 9, "completion_tokens": 1, "total_tokens": 10},
+            },
+        )
+    )
+
+    response: Final = litellm.completion(
+        model="databricks/my-custom-model",
+        messages=[
+            {"role": "system", "content": "You are terse."},
+            {"role": "developer", "content": "Skills: none."},
+            {"role": "user", "content": "Hello"},
+        ],
+        api_base="https://example.databricks.test/serving-endpoints",
+        api_key="fake-databricks-api-key",
+        num_retries=0,
+    )
+
+    assert upstream.call_count == 1
+    request_body: Final = json.loads(upstream.calls[0].request.read())
+    assert request_body["messages"] == [
+        {"role": "system", "content": "You are terse.\n\nSkills: none."},
+        {"role": "user", "content": "Hello"},
+    ]
+    assert response.choices[0].message.content == "Answer"
+
+
+def test_completion_merges_system_messages_when_one_has_empty_content(respx_mock: respx.MockRouter):
+    upstream: Final = respx_mock.post("https://example.databricks.test/serving-endpoints/chat/completions").mock(
+        return_value=httpx.Response(
+            status_code=200,
+            json={
+                "id": "chatcmpl-123",
+                "object": "chat.completion",
+                "created": 1677652288,
+                "model": "my-custom-model",
+                "choices": [{"index": 0, "message": {"role": "assistant", "content": "Answer"}, "finish_reason": "stop"}],
+                "usage": {"prompt_tokens": 9, "completion_tokens": 1, "total_tokens": 10},
+            },
+        )
+    )
+
+    litellm.completion(
+        model="databricks/my-custom-model",
+        messages=[
+            {"role": "system", "content": "You are terse."},
+            {"role": "system", "content": ""},
+            {"role": "user", "content": "Hello"},
+        ],
+        api_base="https://example.databricks.test/serving-endpoints",
+        api_key="fake-databricks-api-key",
+        num_retries=0,
+    )
+
+    request_body: Final = json.loads(upstream.calls[0].request.read())
+    assert request_body["messages"] == [
+        {"role": "system", "content": "You are terse."},
+        {"role": "user", "content": "Hello"},
+    ]
diff --git a/tests/test_litellm/responses/test_responses_api_bridge_flag.py b/tests/test_litellm/responses/test_responses_api_bridge_flag.py
index 2f64cc8debc..16135106b41 100644
--- a/tests/test_litellm/responses/test_responses_api_bridge_flag.py
+++ b/tests/test_litellm/responses/test_responses_api_bridge_flag.py
@@ -262,6 +262,126 @@ class TestUseResponsesApiBridgeFlag:
         assert request_body["messages"] == [{"role": "user", "content": "Hello"}]
         assert response.output[0].content[0].text == "Answer"
 
+    def test_bridge_drops_client_metadata_even_when_allowed_openai_params_names_it(
+        self, respx_mock: respx.MockRouter
+    ):
+        upstream: Final = respx_mock.post("https://api.openai.com/v1/chat/completions").mock(
+            return_value=httpx.Response(
+                status_code=200,
+                json={
+                    "id": "chatcmpl-123",
+                    "object": "chat.completion",
+                    "created": 1677652288,
+                    "model": "my-custom-model",
+                    "choices": [
+                        {"index": 0, "message": {"role": "assistant", "content": "Answer"}, "finish_reason": "stop"}
+                    ],
+                    "usage": {"prompt_tokens": 9, "completion_tokens": 1, "total_tokens": 10},
+                },
+            )
+        )
+
+        response: Final = litellm.responses(
+            model="openai/my-custom-model",
+            input="Hello",
+            use_chat_completions_api=True,
+            allowed_openai_params=["client_metadata"],
+            client_metadata={"turn_id": "turn-1", "thread_id": "thread-1"},
+            api_key="fake-provider-api-key",
+            num_retries=0,
+        )
+
+        assert upstream.call_count == 1
+        request_body: Final = json.loads(upstream.calls[0].request.read())
+        assert "client_metadata" not in request_body
+        assert request_body["messages"] == [{"role": "user", "content": "Hello"}]
+        assert response.output[0].content[0].text == "Answer"
+
+    def test_bridge_merges_instructions_and_developer_input_for_databricks(self, respx_mock: respx.MockRouter):
+        upstream: Final = respx_mock.post("https://example.databricks.test/serving-endpoints/chat/completions").mock(
+            return_value=httpx.Response(
+                status_code=200,
+                json={
+                    "id": "chatcmpl-123",
+                    "object": "chat.completion",
+                    "created": 1677652288,
+                    "model": "my-custom-model",
+                    "choices": [
+                        {"index": 0, "message": {"role": "assistant", "content": "Answer"}, "finish_reason": "stop"}
+                    ],
+                    "usage": {"prompt_tokens": 9, "completion_tokens": 1, "total_tokens": 10},
+                },
+            )
+        )
+
+        response: Final = litellm.responses(
+            model="databricks/my-custom-model",
+            instructions="You are terse.",
+            input=[
+                {"role": "developer", "content": [{"type": "input_text", "text": "Skills: none."}]},
+                {"role": "user", "content": [{"type": "input_text", "text": "Hello"}]},
+            ],
+            client_metadata={"turn_id": "turn-1", "thread_id": "thread-1"},
+            chat_template_kwargs={"thinking": True},
+            api_base="https://example.databricks.test/serving-endpoints",
+            api_key="fake-databricks-api-key",
+            num_retries=0,
+        )
+
+        assert upstream.call_count == 1
+        request_body: Final = json.loads(upstream.calls[0].request.read())
+        assert request_body["messages"] == [
+            {
+                "role": "system",
+                "content": [{"type": "text", "text": "You are terse."}, {"type": "text", "text": "Skills: none."}],
+            },
+            {"role": "user", "content": [{"type": "text", "text": "Hello"}]},
+        ]
+        assert "client_metadata" not in request_body
+        assert request_body["chat_template_kwargs"] == {"thinking": True}
+        assert response.output[0].content[0].text == "Answer"
+
+    def test_bridge_drops_client_metadata_for_provider_without_native_config(self, respx_mock: respx.MockRouter):
+        upstream: Final = respx_mock.post("https://example.databricks.test/serving-endpoints/chat/completions").mock(
+            return_value=httpx.Response(
+                status_code=200,
+                json={
+                    "id": "chatcmpl-123",
+                    "object": "chat.completion",
+                    "created": 1677652288,
+                    "model": "my-custom-model",
+                    "choices": [
+                        {"index": 0, "message": {"role": "assistant", "content": "Answer"}, "finish_reason": "stop"}
+                    ],
+                    "usage": {"prompt_tokens": 9, "completion_tokens": 1, "total_tokens": 10},
+                },
+            )
+        )
+
+        response: Final = litellm.responses(
+            model="databricks/my-custom-model",
+            input="Hello",
+            client_metadata={
+                "turn_id": "turn-1",
+                "thread_id": "thread-1",
+                "session_id": "session-1",
+                "root_turn_id": "turn-1",
+                "x-codex-installation-id": "install-1",
+                "x-codex-turn-metadata": '{"turn_id":"turn-1"}',
+            },
+            chat_template_kwargs={"thinking": True},
+            api_base="https://example.databricks.test/serving-endpoints",
+            api_key="fake-databricks-api-key",
+            num_retries=0,
+        )
+
+        assert upstream.call_count == 1
+        request_body: Final = json.loads(upstream.calls[0].request.read())
+        assert "client_metadata" not in request_body
+        assert request_body["chat_template_kwargs"] == {"thinking": True}
+        assert request_body["messages"] == [{"role": "user", "content": "Hello"}]
+        assert response.output[0].content[0].text == "Answer"
+
     def test_bridge_keeps_deployment_credentials_while_dropping_unknown_params(self, respx_mock: respx.MockRouter):
         upstream: Final = respx_mock.post(
             "https://example-resource.openai.azure.com/openai/deployments/my-deployment/chat/completions",