fix(anthropic): stop logging rejected encrypted reasoning

Quote the retry helper return type so importing litellm no longer evaluates a string alias with |. The warning keeps provider, model, status, and error code, and leaves the ciphertext out.

litellm/llms/anthropic/messages/adapters/handler.py

@@ -84,15 +84,46 @@ class _ChatTargetReasoning:
     summary: str | None = None
 
 
+def _provider_error_code(body: object) -> str | None:
+    mapping: Final = as_str_mapping(body)
+    if mapping is None:
+        return None
+    nested: Final = as_str_mapping(mapping.get("error"))
+    source: Final = nested if nested is not None else mapping
+    code: Final = source.get("code")
+    return code if isinstance(code, str) else None
+
+
+def _logged_rejection_code(error: litellm.BadRequestError) -> str:
+    if error.code == "invalid_encrypted_content" or _provider_error_code(error.body) == "invalid_encrypted_content":
+        return "invalid_encrypted_content"
+    if "invalid_encrypted_content" in str(error):
+        return "invalid_encrypted_content"
+    return "could_not_be_verified"
+
+
+def _completion_text(completion_kwargs: _CompletionKwargs, key: str) -> str:
+    value: Final = completion_kwargs.get(key)
+    return value if isinstance(value, str) else ""
+
+
 def _messages_without_rejected_reasoning(
     messages: _AnthropicMessages,
     error: litellm.BadRequestError,
-) -> _AnthropicMessages | None:
+    completion_kwargs: _CompletionKwargs,
+) -> "_AnthropicMessages | None":
     error_message: Final = str(error)
     rejected: Final = "invalid_encrypted_content" in error_message or "could not be verified" in error_message
     if not rejected or not messages_carry_encrypted_reasoning(messages):
         return None
-    verbose_logger.warning("Backend rejected replayed encrypted reasoning, retrying once without it: %s", error)
+    verbose_logger.warning(
+        "Backend rejected replayed encrypted reasoning, retrying once without it. "
+        "provider=%s model=%s status=%s code=%s",
+        _completion_text(completion_kwargs, "custom_llm_provider"),
+        _completion_text(completion_kwargs, "model"),
+        error.status_code,
+        _logged_rejection_code(error),
+    )
     return _ANTHROPIC_MESSAGES.validate_python(strip_encrypted_reasoning_blocks_from_anthropic_messages(messages))
 
 
@@ -104,7 +135,7 @@ async def _acompletion_without_rejected_reasoning(
     try:
         return completion_kwargs, await litellm.acompletion(**completion_kwargs)
     except litellm.BadRequestError as error:
-        replayed_messages: Final = _messages_without_rejected_reasoning(messages, error)
+        replayed_messages: Final = _messages_without_rejected_reasoning(messages, error, completion_kwargs)
         if replayed_messages is None:
             raise
         replay_kwargs: Final = prepare_replay(replayed_messages)
@@ -119,7 +150,7 @@ def _completion_without_rejected_reasoning(
     try:
         return completion_kwargs, litellm.completion(**completion_kwargs)
     except litellm.BadRequestError as error:
-        replayed_messages: Final = _messages_without_rejected_reasoning(messages, error)
+        replayed_messages: Final = _messages_without_rejected_reasoning(messages, error, completion_kwargs)
         if replayed_messages is None:
             raise
         replay_kwargs: Final = prepare_replay(replayed_messages)

tests/unit/llms/anthropic/messages/adapters/test_anthropic_messages_adapters_transformation.py

@@ -5827,25 +5827,40 @@ def _sent_reasoning_items(request: httpx.Request) -> list[object]:
 @pytest.mark.usefixtures("_chat_bridge_httpx")
 async def test_async_messages_retry_once_without_reasoning_the_backend_cannot_decrypt(
     respx_mock: respx.MockRouter,
+    caplog: pytest.LogCaptureFixture,
 ) -> None:
     route: Final = respx_mock.post(url__regex=_RETRY_URL).mock(
         side_effect=[_RETRY_REJECTION, httpx.Response(200, json=_RETRY_REPLY)]
     )
 
-    response: Final = await litellm.anthropic.messages.acreate(
-        model="azure/gpt-5.4-nano",
-        api_base=_RETRY_API_BASE,
-        api_key="fake-key",
-        api_version="2025-04-01-preview",
-        max_tokens=64,
-        tools=_RETRY_TOOLS,
-        messages=_history_with_foreign_reasoning(),
-    )
+    with caplog.at_level(logging.WARNING, logger="LiteLLM"):
+        response: Final = await litellm.anthropic.messages.acreate(
+            model="azure/gpt-5.4-nano",
+            api_base=_RETRY_API_BASE,
+            api_key="fake-key",
+            api_version="2025-04-01-preview",
+            max_tokens=64,
+            tools=_RETRY_TOOLS,
+            messages=_history_with_foreign_reasoning(),
+        )
 
+    warnings: Final = tuple(
+        record.getMessage()
+        for record in caplog.records
+        if record.levelno >= logging.WARNING and record.name == "LiteLLM"
+    )
+    retry_warnings: Final = tuple(message for message in warnings if "retrying once without it" in message)
     assert route.call_count == 2
     assert len(_sent_reasoning_items(route.calls[0].request)) == 1
     assert _sent_reasoning_items(route.calls[1].request) == []
     assert [block["text"] for block in response["content"] if block["type"] == "text"] == ["Oslo"]
+    assert retry_warnings == (
+        "Backend rejected replayed encrypted reasoning, retrying once without it. "
+        "provider=azure model=azure/gpt-5.4-nano status=400 code=invalid_encrypted_content",
+    )
+    assert all(
+        "gAAA_foreign" not in message and "litellm_encrypted_reasoning:" not in message for message in warnings
+    )
 
 
 @pytest.mark.usefixtures("_chat_bridge_httpx")