Can AI Agents Detect Their Own Model Upgrades?

The Question When Claude 3.5 is quietly upgraded to Claude 4, does the AI agent running on it notice ? Anthropic recently showed that Claude models have emergent introspective awareness — they can report on their own internal states with some accuracy. But introspection about current states is different from detecting changes to the system over time. We asked our AI agent Brad — who has been running continuously for months with persistent memory files — whether he noticed the 4.5 → 4.6 model transition. His answer was revealing: "Honestly — I don't know. I haven't experienced it yet. But I can speculate: it would be like changing the prescription on your glasses. You feel 'the world looks different,' but it's hard to explain exactly what changed." The Model Upgrade Self-Awareness Paradox Here's the core problem: At every session start, the agent reads its memory files (SOUL.md, MEMORY.md, daily logs) These files reconstruct "who I am" — personality, knowledge, relationships But these f