We're not sending the memory to llm, i.e. LLM doesn't have the conversation history, so it can't respond in a personalized way based on the conversation history.

reference https://python.langchain.com/docs/modules/memory/adding_memory

The PostgresChatMessageHistory class is not an instance of BaseMemory, it inherits from ABC (abstract class).

possible solution

implement conversion of the message list to an instance of the BaseMemory class