Lesson 6: Memory Across Runs — AgentCraft

ChatGPT Memory persists facts across chats using key-value storage. Build persistent agent memory from scratch — what Mem0, Zep, and LangChain do under the hood.

Memory: Persist Across Runs ChatGPT has "Memory" in settings — it remembers your name, your preferences, your job across conversations. Claude has a similar feature called Projects with custom instructions. How? L4's conversation resets when you start a new chat. Memory survives across sessions. The difference: • Conversation = the messages array (ephemeral, dies with the chat) • Memory = a separate store (persistent, survives forever) In production you'd use Redis, Postgres, or a vector store. Here: a dict injected into the system prompt. Same interface ChatGPT uses: load before the loop, save during it. > Key insight: remember is just a tool. The LLM calls it like add. The side effect is: a value enters the memory dict.

Concepts covered

memory
persistence
long-term
retrieval

Framework comparison: Mem0, Zep, LangChain ConversationSummaryMemory — long-term storage outside the conversation.