From 3371eb160742f664ff7e1f5d7eeaa4e36e7c2c6c Mon Sep 17 00:00:00 2001
From: Frost Ming <me@frostming.com>
Date: Wed, 31 Jan 2024 16:17:50 +0800
Subject: [PATCH] fix: correct schema for optional type (#4459)

Signed-off-by: Frost Ming <me@frostming.com>
---
 src/_bentoml_sdk/api.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/_bentoml_sdk/api.py b/src/_bentoml_sdk/api.py
index ba0cf2d0803..c000b82a513 100644
--- a/src/_bentoml_sdk/api.py
+++ b/src/_bentoml_sdk/api.py
@@ -211,7 +211,7 @@ def _flatten_field(
 
 def _flatten_model_schema(model: type[IODescriptor]) -> dict[str, t.Any]:
     schema = model.model_json_schema()
-    if not schema.get("properties") or "$defs" not in schema:
+    if not schema.get("properties"):
         return schema
     defs = schema.pop("$defs", {})
     return _flatten_field(schema, defs)