From 8aa5c6d925521fcf08bea57e0d309cbf1d72f55e Mon Sep 17 00:00:00 2001
From: detteiu0330 <detteiu.index545@gmail.com>
Date: Sat, 12 Apr 2025 12:21:25 +0900
Subject: [PATCH] Fix JSON serialization to handle non-ASCII characters in
 _convert_to_content

---
 src/mcp/server/fastmcp/server.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/mcp/server/fastmcp/server.py b/src/mcp/server/fastmcp/server.py
index bf0ce880a5..9c6060e148 100644
--- a/src/mcp/server/fastmcp/server.py
+++ b/src/mcp/server/fastmcp/server.py
@@ -551,7 +551,9 @@ def _convert_to_content(
 
     if not isinstance(result, str):
         try:
-            result = json.dumps(pydantic_core.to_jsonable_python(result))
+            result = json.dumps(
+                pydantic_core.to_jsonable_python(result), ensure_ascii=False
+            )
         except Exception:
             result = str(result)