From 4c533e0b164a3b8e2ae734383323a1ebc0a441fa Mon Sep 17 00:00:00 2001
From: Hassieb Pakzad <68423100+hassiebp@users.noreply.github.com>
Date: Mon, 14 Jul 2025 10:42:09 +0200
Subject: [PATCH] fix(serializer): NaN to string rather than None

---
 langfuse/_utils/serializer.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/langfuse/_utils/serializer.py b/langfuse/_utils/serializer.py
index 0d6237f1c..e4b625a6e 100644
--- a/langfuse/_utils/serializer.py
+++ b/langfuse/_utils/serializer.py
@@ -63,7 +63,7 @@ def default(self, obj: Any):
                 return obj.tolist()
 
             if isinstance(obj, float) and math.isnan(obj):
-                return None
+                return "NaN"
 
             if isinstance(obj, float) and math.isinf(obj):
                 return "Infinity"