diff --git a/examples/web_search_pause_turn.py b/examples/web_search_pause_turn.py
new file mode 100644
index 00000000..0ed18a85
--- /dev/null
+++ b/examples/web_search_pause_turn.py
@@ -0,0 +1,39 @@
+from __future__ import annotations
+
+from anthropic import Anthropic
+from anthropic.types import Message, MessageParam
+
+client = Anthropic()
+
+
+def assistant_turn_from_message(message: Message) -> MessageParam:
+    """Preserve paused server-tool blocks exactly as the SDK returned them."""
+    return {"role": "assistant", "content": message.content}
+
+
+messages: list[MessageParam] = [
+    {"role": "user", "content": "Search for the latest Claude web search documentation."}
+]
+
+while True:
+    message = client.messages.create(
+        model="claude-sonnet-4-5-20250929",
+        max_tokens=1024,
+        messages=messages,
+        tools=[
+            {
+                "name": "web_search",
+                "type": "web_search_20250305",
+            }
+        ],
+    )
+
+    if message.stop_reason != "pause_turn":
+        break
+
+    # Keep the full assistant turn intact. Splitting, filtering, or rewriting
+    # individual server_tool_use blocks can orphan tool state on the next request.
+    messages.append(assistant_turn_from_message(message))
+
+
+print(message.model_dump_json(indent=2))
diff --git a/tests/test_transform.py b/tests/test_transform.py
index 4a874ff8..7427ba78 100644
--- a/tests/test_transform.py
+++ b/tests/test_transform.py
@@ -8,6 +8,7 @@
 
 import pytest
 
+from anthropic.types import ServerToolUseBlock
 from anthropic._types import Base64FileInput, omit, not_given
 from anthropic._utils import (
     PropertyInfo,
@@ -17,6 +18,7 @@
 )
 from anthropic._compat import PYDANTIC_V1
 from anthropic._models import BaseModel
+from anthropic.types.message_create_params import MessageCreateParamsNonStreaming
 
 _T = TypeVar("_T")
 
@@ -104,6 +106,48 @@ async def test_union_of_typeddict(use_async: bool) -> None:
     }
 
 
+@parametrize
+@pytest.mark.asyncio
+async def test_message_params_preserve_server_tool_use_blocks(use_async: bool) -> None:
+    server_tool_use = ServerToolUseBlock(
+        id="srvtoolu_123",
+        input={"query": "latest Claude docs"},
+        name="web_search",
+        type="server_tool_use",
+    )
+
+    assert await transform(
+        {
+            "max_tokens": 1024,
+            "model": "claude-sonnet-4-5-20250929",
+            "messages": [
+                {
+                    "role": "assistant",
+                    "content": [server_tool_use],
+                }
+            ],
+        },
+        MessageCreateParamsNonStreaming,
+        use_async,
+    ) == {
+        "max_tokens": 1024,
+        "model": "claude-sonnet-4-5-20250929",
+        "messages": [
+            {
+                "role": "assistant",
+                "content": [
+                    {
+                        "id": "srvtoolu_123",
+                        "input": {"query": "latest Claude docs"},
+                        "name": "web_search",
+                        "type": "server_tool_use",
+                    }
+                ],
+            }
+        ],
+    }
+
+
 class Foo5(TypedDict):
     foo: Annotated[Union[Bar4, List[Baz4]], PropertyInfo(alias="FOO")]