fix(guardrails): support array-type content in Presidio pre-call hook

litellm/proxy/guardrails/guardrail_hooks/presidio.py

@@ -14,8 +14,10 @@
 from typing import (
     Any,
     AsyncGenerator,
+    Coroutine,
     Dict,
     List,
+    Literal,
     Optional,
     Tuple,
     Union,
@@ -404,8 +406,12 @@ async def async_pre_call_hook(
             verbose_proxy_logger.debug("content_safety: %s", content_safety)
             presidio_config = self.get_presidio_settings_from_request_data(data)
             messages = data["messages"]
-            tasks = []
-            for m in messages:
+            tasks: list[Coroutine[Any, Any, str]] = []
+            targets: list[
+                tuple[Literal["str"], int] | tuple[Literal["block"], int, int, str]
+            ] = []  # track where to write back each presidio result
+
+            for msg_idx, m in enumerate(messages):
                 content = m.get("content", None)
                 if content is None:
                     continue
@@ -418,15 +424,36 @@ async def async_pre_call_hook(
                             request_data=data,
                         )
                     )
+
+                    # string content -> write back to messages[msg_idx]['content']
+                    targets.append(("str", msg_idx))
+                elif isinstance(content, list):
+                    # handle only dict blocks with a string 'text' field
+                    for b_idx, block in enumerate(content):
+                        if isinstance(block, dict) and isinstance(block.get("text"), str):
+                            tasks.append(
+                                self.check_pii(
+                                    text=block["text"],
+                                    output_parse_pii=self.output_parse_pii,
+                                    presidio_config=presidio_config,
+                                    request_data=data,
+                                )
+                            )
+
+                            # block content -> write back to messages[msg_idx]['content'][b_idx]['text']
+                            targets.append(("block", msg_idx, b_idx, "text"))
+
             responses = await asyncio.gather(*tasks)
-            for index, r in enumerate(responses):
-                content = messages[index].get("content", None)
-                if content is None:
-                    continue
-                if isinstance(content, str):
-                    messages[index][
-                        "content"
-                    ] = r  # replace content with redacted string
+
+            # write results back to the exact targets collected above
+            for redacted, tgt in zip(responses, targets):
+                if tgt[0] == "str":
+                    _, mi = tgt
+                    messages[mi]["content"] = redacted
+                else:
+                    _, mi, bi, key = tgt
+                    messages[mi]["content"][bi][key] = redacted
+
             verbose_proxy_logger.debug(
                 f"Presidio PII Masking: Redacted pii message: {data['messages']}"
             )
@@ -672,4 +699,4 @@ def update_in_memory_litellm_params(self, litellm_params: LitellmParams) -> None
         """
         super().update_in_memory_litellm_params(litellm_params)
         if litellm_params.pii_entities_config:
-            self.pii_entities_config = litellm_params.pii_entities_config
+            self.pii_entities_config = litellm_params.pii_entities_config

tests/guardrails_tests/test_presidio_pii.py

@@ -592,3 +592,48 @@ async def test_presidio_language_configuration_with_per_request_override():
     # Verify the default language (German) is used
     assert analyze_request_default["language"] == "de"
     assert analyze_request_default["text"] == test_text
+
+
+@pytest.mark.asyncio
+async def test_presidio_pre_call_hook_with_content_list_single_block():
+    """
+    Ensure async_pre_call_hook redacts list-of-blocks content with a 'text' field.
+    """
+    mock_redacted = {
+        "text": "email is <EMAIL_ADDRESS>",
+        "items": [
+            {
+                "start": 9,
+                "end": 24,
+                "entity_type": "EMAIL_ADDRESS",
+                "text": "<EMAIL_ADDRESS>",
+                "operator": "replace",
+            }
+        ],
+    }
+
+    presidio_guardrail = _OPTIONAL_PresidioPIIMasking(
+        mock_testing=True,
+        mock_redacted_text=mock_redacted,
+    )
+
+    data = {
+        "messages": [
+            {
+                "role": "user",
+                "content": [
+                    {"type": "text", "text": "email is [email protected]"}
+                ],
+            }
+        ]
+    }
+
+    new_data = await presidio_guardrail.async_pre_call_hook(
+        user_api_key_dict=UserAPIKeyAuth(api_key="x"),
+        cache=DualCache(),
+        data=data,
+        call_type="completion",
+    )
+
+    assert isinstance(new_data["messages"][0]["content"], list)
+    assert new_data["messages"][0]["content"][0]["text"] == "email is <EMAIL_ADDRESS>"