The Microsoft Agent Framework enables developers to store chat history using external storage solutions like Azure Cosmos DB, enhancing agent capabilities for context retention and personalization. As of January 12, 2026, the framework supports both in-memory and persistent storage models, with external storage allowing agents to maintain conversation context across sessions. Using the Azure CosmosDB NoSQL Vector Store connector, developers can implement a custom ChatMessageStore to persist interactions in Cosmos DB.

This approach is especially valuable for applications requiring long-term memory, such as customer support or personalized fitness assistants. By replacing default in-memory storage, agents built on services like OpenAI Chat Completion can leverage external databases to retain user preferences and conversation history. Implementation involves configuring the CosmosClient, creating a custom ChatMessageStore class, and integrating it into the agent using ChatMessageStoreFactory.

This solution benefits developers building scalable AI agents, offering flexibility in data persistence and improved user experiences. Organizations utilizing Microsoft Agent Framework can enhance agent intelligence and continuity through external storage integration.