Changes in the System Prompt Between Claude Opus 4.6 and 4.7

Summary

Simon Willison documents the differences in Anthropic's published system prompts between Claude Opus 4.6 and the newly released Opus 4.7. Anthropic remains the only major AI lab to publicly share the system prompts used in their consumer-facing chat products, with their archive now extending back to Claude 3 in July 2024. The analysis highlights how Anthropic iterates on behavioral instructions, guardrails, and persona framing across model generations. While the full article content was truncat