From 069443f322ed8b4aa079f24387b15075823ea313 Mon Sep 17 00:00:00 2001
From: Hassieb Pakzad <68423100+hassiebp@users.noreply.github.com>
Date: Mon, 8 Sep 2025 13:40:12 +0200
Subject: [PATCH] fix(langchain): set cost to zero on errors

---
 langfuse/langchain/CallbackHandler.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/langfuse/langchain/CallbackHandler.py b/langfuse/langchain/CallbackHandler.py
index 20bfa2534..b4c27c3bc 100644
--- a/langfuse/langchain/CallbackHandler.py
+++ b/langfuse/langchain/CallbackHandler.py
@@ -218,6 +218,7 @@ def on_retriever_error(
                     level="ERROR",
                     status_message=str(error),
                     input=kwargs.get("inputs"),
+                    cost_details={"total": 0},
                 ).end()
 
         except Exception as e:
@@ -527,6 +528,7 @@ def on_chain_error(
                     ),
                     status_message=str(error) if level else None,
                     input=kwargs.get("inputs"),
+                    cost_details={"total": 0},
                 ).end()
 
         except Exception as e:
@@ -733,6 +735,7 @@ def on_tool_error(
                     status_message=str(error),
                     level="ERROR",
                     input=kwargs.get("inputs"),
+                    cost_details={"total": 0},
                 ).end()
 
         except Exception as e:
@@ -913,6 +916,7 @@ def on_llm_error(
                     status_message=str(error),
                     level="ERROR",
                     input=kwargs.get("inputs"),
+                    cost_details={"total": 0},
                 ).end()
 
         except Exception as e: