mem0ai/mem0 · error · ValueError
No valid messages found in the messages list
Error message
No valid messages found in the messages list
What it means
Error "No valid messages found in the messages list" thrown in mem0ai/mem0.
Source
Thrown at mem0/llms/langchain.py:90
Returns:
str: The generated response.
"""
# Convert the messages to LangChain's tuple format
langchain_messages = []
for message in messages:
role = message["role"]
content = message["content"]
if role == "system":
langchain_messages.append(("system", content))
elif role == "user":
langchain_messages.append(("human", content))
elif role == "assistant":
langchain_messages.append(("ai", content))
if not langchain_messages:
raise ValueError("No valid messages found in the messages list")
langchain_model = self.langchain_model
if tools:
langchain_model = langchain_model.bind_tools(tools=tools, tool_choice=tool_choice)
response: AIMessage = langchain_model.invoke(langchain_messages, **kwargs)
return self._parse_response(response, tools)
View on GitHub (pinned to 001c235229)
Solutions
- Ensure the messages list contains at least one message with a valid role and non-empty content.
When it happens
Trigger: Thrown at mem0/llms/langchain.py:90 when the library encounters an invalid state.
Common situations: See trigger scenarios.
AI-assisted analysis of mem0ai/mem0@001c235229 (2026-08-15).
Data as JSON: /api/errors/6700962c1c50159e.
Report an issue: GitHub.