Fable 5.1's Claude.ai System Prompt is now 138k tokens (up from 24k in May 2025 when we had Claude 3.7 Sonnet)

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2026-09-03 08:34 · r/ClaudeAI
Fable 5.1's Claude.ai System Prompt is now 138k tokens (up from 24k in May 2025 when we had Claude 3.7 Sonnet)

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