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Anthropic says it cut 80 percent of Claude Code's system prompt because Fable 5 models "want a smaller system prompt"

Anthropic has cut the system prompt for Claude Code by 80 percent. According to staffer Tariq Shihipar, the new Fable 5 models need fewer instructions and examples. Guidelines can even hold the models back because they're "more imaginative" than what they're given. Instead of strict rules, Anthropic now steers through context. The article Anthropic says it cut 80 percent of Claude Code's system prompt because Fable 5 models "want a smaller system prompt" appeared first on

Anthropic says it cut 80 percent of Claude Code's system prompt because Fable 5 models "want a smaller system prompt"
Primary source the-decoder.com ↗

Published July 2, 2026 · Category: AI Briefing

Overview

Anthropic has cut the system prompt for Claude Code by 80 percent. According to staffer Tariq Shihipar, the new Fable 5 models need fewer instructions and examples. Guidelines can even hold the models back because they're "more imaginative" than what they're given. Instead of strict rules, Anthropic now steers through context.

Details

The article Anthropic says it cut 80 percent of Claude Code's system prompt because Fable 5 models "want a smaller system prompt" appeared first on The Decoder.

Source

Originally published at the-decoder.com.

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