The model is fine. The session is broken.

AI agent products, though technically capable of performing complex tasks such as holding long conversations and integrating with external tools, often struggle with reliability and user experience due to infrastructural issues unrelated to the models themselves. Challenges arise in maintaining continuous and seamless interactions as sessions frequently break due to network unreliability, device switches, and other disruptions. These issues are not caused by the AI models but rather by the lack of an effective delivery layer that can ensure persistence, multi-device access, and seamless recovery from interruptions. Companies across the industry are independently attempting to solve these problems by building custom solutions or using third-party tools like WebSockets and Redis Streams, but this often requires significant engineering effort. This has led to the emergence of "durable sessions," which offer persistent, addressable connections that maintain session continuity across devices and network failures. The need for a robust delivery layer is increasingly recognized as crucial for ensuring a reliable user experience, allowing AI products to be both effective and user-friendly.