fix - log langfuse prompt

litellm/litellm_core_utils/llm_request_utils.py

@@ -0,0 +1,30 @@
+from typing import Dict, Optional
+
+from langfuse.model import TextPromptClient
+
+
+def _ensure_extra_body_is_safe(extra_body: Optional[Dict]) -> Optional[Dict]:
+    """
+    Ensure that the extra_body sent in the request is safe,  otherwise users will see this error
+
+    "Object of type TextPromptClient is not JSON serializable
+
+
+    Relevant Issue: https://github.com/BerriAI/litellm/issues/4140
+    """
+    if extra_body is None:
+        return None
+
+    if not isinstance(extra_body, dict):
+        return extra_body
+
+    if "metadata" in extra_body and isinstance(extra_body["metadata"], dict):
+        if "prompt" in extra_body["metadata"]:
+            _prompt = extra_body["metadata"].get("prompt")
+
+            # users can send Langfuse TextPromptClient objects, so we need to convert them to dicts
+            # Langfuse TextPromptClients have .__dict__ attribute
+            if _prompt is not None and hasattr(_prompt, "__dict__"):
+                extra_body["metadata"]["prompt"] = _prompt.__dict__
+
+    return extra_body