LangMem SDK is a new library designed to enhance AI agents by incorporating long-term memory capabilities, allowing them to learn and improve over time. The SDK offers tools to extract information from conversations, optimize agent behavior, and maintain memories of behaviors, facts, and events, integrating seamlessly with any storage system and agent framework. A managed service is also available, providing additional long-term memory results for free. LangMem supports different memory types, including semantic memory for facts and knowledge, procedural memory for behavior patterns, and episodic memory for past experiences, each serving distinct functions to build adaptive agents. The SDK emphasizes the importance of mapping agent capabilities to specific memory types and questions like which behaviors should adapt or remain fixed, what knowledge to track, and when memories should be recalled. Privacy and performance considerations are addressed by scoping memory to users or teams, while integration with LangGraph ensures effective short-term memory management. LangMem aims to make AI experiences smarter and more personalized, building on prior work with LangGraph's memory layer, and it invites users to explore custom memory systems and join their team in advancing adaptive AI agents.