fix(guardrails): preserve guardrail_info when storing YAML guardrails

Address PR review feedback. InMemoryGuardrailHandler.initialize_guardrail was
constructing the parsed Guardrail without guardrail_info, so even after the
endpoint fallback fix, /guardrails/usage/{overview,detail} couldn't render
type or description for YAML-defined guardrails — both fields would silently
default to "Guardrail" / None at runtime.

Pass guardrail_info through into IN_MEMORY_GUARDRAILS, and add a regression
test that exercises the real handler (not a mock) end-to-end.

Also refactors _get_guardrail_attrs to use the new _get_guardrail_field helper
for consistency.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

litellm/proxy/guardrails/guardrail_registry.py

@@ -487,6 +487,7 @@ class InMemoryGuardrailHandler:
             guardrail_id=guardrail.get("guardrail_id"),
             guardrail_name=guardrail["guardrail_name"],
             litellm_params=litellm_params,
+            guardrail_info=guardrail.get("guardrail_info"),
         )
 
         # store references to the guardrail in memory

litellm/proxy/guardrails/usage_endpoints.py

@@ -137,17 +137,6 @@ def _chart_from_metrics(metrics: Any) -> List[Dict[str, Any]]:
     ]
 
 
-def _get_guardrail_attrs(g: Any) -> tuple[Any, str]:
-    """Get (guardrail_id, display_name) from guardrail - handles Prisma model or dict."""
-    gid = getattr(g, "guardrail_id", None) or (
-        g.get("guardrail_id") if isinstance(g, dict) else None
-    )
-    name = getattr(g, "guardrail_name", None) or (
-        g.get("guardrail_name") if isinstance(g, dict) else None
-    )
-    return gid, (name or gid or "")
-
-
 def _get_guardrail_field(g: Any, field: str) -> Any:
     """Read `field` off a guardrail (Prisma row attr or dict/TypedDict key)."""
     if isinstance(g, dict):
@@ -155,6 +144,13 @@ def _get_guardrail_field(g: Any, field: str) -> Any:
     return getattr(g, field, None)
 
 
+def _get_guardrail_attrs(g: Any) -> tuple[Any, str]:
+    """Get (guardrail_id, display_name) from guardrail - handles Prisma model or dict."""
+    gid = _get_guardrail_field(g, "guardrail_id")
+    name = _get_guardrail_field(g, "guardrail_name")
+    return gid, (name or gid or "")
+
+
 def _to_dict(value: Any) -> Dict[str, Any]:
     """Coerce a LitellmParams / dict / None into a plain dict."""
     if isinstance(value, LitellmParams):

tests/test_litellm/proxy/guardrails/test_usage_endpoints.py

@@ -304,3 +304,57 @@ async def test_usage_logs_includes_logical_name_for_yaml_guardrail(
     ), f"Expected 'in' filter to include UUID + logical name, got {gid_filter}"
     assert "yaml-uuid-xyz" in gid_filter["in"]
     assert "my-yaml-pii" in gid_filter["in"]
+
+
+# ---- Integration: real InMemoryGuardrailHandler ----------------------------
+
+
+@pytest.mark.asyncio
+async def test_usage_detail_with_real_in_memory_handler_preserves_guardrail_info(
+    mock_prisma, mocker
+):
+    """
+    Regression: `initialize_guardrail` must persist `guardrail_info` into
+    IN_MEMORY_GUARDRAILS so that /usage/detail can render `type` and `description`
+    for YAML-defined guardrails. Exercises the real handler (not a Mock).
+    """
+    from litellm.proxy.guardrails.guardrail_registry import (
+        IN_MEMORY_GUARDRAIL_HANDLER,
+    )
+
+    # Bypass callback initialization; we only care about what gets stored.
+    mocker.patch.object(
+        IN_MEMORY_GUARDRAIL_HANDLER,
+        "initialize_custom_guardrail",
+        return_value=None,
+    )
+
+    yaml_input = {
+        "guardrail_id": "real-handler-yaml",
+        "guardrail_name": "real-handler-pii",
+        # `module.Class` form routes to initialize_custom_guardrail (mocked above)
+        "litellm_params": {
+            "guardrail": "my_module.MyCustomGuardrail",
+            "mode": "pre_call",
+        },
+        "guardrail_info": {"type": "PII", "description": "Real-handler-defined"},
+    }
+    try:
+        IN_MEMORY_GUARDRAIL_HANDLER.initialize_guardrail(guardrail=yaml_input)
+
+        response = await guardrails_usage_detail(
+            guardrail_id="real-handler-yaml",
+            start_date=START_DATE,
+            end_date=END_DATE,
+            user_api_key_dict=ADMIN_AUTH,
+        )
+
+        assert response.guardrail_id == "real-handler-yaml"
+        assert response.provider == "my_module.MyCustomGuardrail"
+        assert response.type == "PII"
+        assert response.description == "Real-handler-defined"
+    finally:
+        IN_MEMORY_GUARDRAIL_HANDLER.IN_MEMORY_GUARDRAILS.pop("real-handler-yaml", None)
+        IN_MEMORY_GUARDRAIL_HANDLER.guardrail_id_to_custom_guardrail.pop(
+            "real-handler-yaml", None
+        )