Claude Opus 4.8 Memory: Why Context Windows Aren't Enough

Claude Opus 4.8 offers a 1M token context window but cannot retain user information across sessions, highlighting the distinction between context (what a model sees in the current interaction) and memory (what an application preserves across sessions). The post uses live tests with Anthropic’s Messages API and Mem0’s REST API to demonstrate this difference with real outputs rather than simulated results. It argues that persistent memory layers like Mem0 are necessary for building truly personalized AI applications on top of models like Claude Opus 4.8.