Reverse Engineering Reveals True Reduction in Claude Code System Prompts

PawelHuryn · x · 2026-07-22

Addressing rumors of an 80% cut to Claude Code's system prompt, the author captured the real prompts for all 6 models using a fake ANTHROPICBASEURL. The analysis reveals the actual reduction is closer to 70%: the 80% figure only applies when memory is disabled. The memory rules weren't deleted but are simply not loaded when memory is off. The repository includes the full system prompts, diffs between them, and a one-command trick to capture any model's real prompt.

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