Changes in the system prompt between Claude Opus 4.6 and 4.7
The system prompt update for Claude Opus 4.7 reveals the evolution of AI assistants from passive responders to proactive tool-users, deep task executors, and more responsible safety frameworks.
Simon Willison · Apr 19, 2026
Claude system prompts as a git timeline
Simon Willison transformed Anthropic's published Claude system prompt history into a Git-based tool, enabling developers to trace prompt evolution like code changes, revealing a new paradigm for AI behavior debugging and understanding.
Simon Willison · Apr 18, 2026