Fable 5.1

Specifications

No specifications recorded yet.

Latest developments

AI #184: Post Post Mortem Zvi (Don't Worry About the Vase) · 19 hours ago · 16 Fable 5.1 Ben's Bites · 20 hours ago · 15

Claude's new system prompt really doesn't want to reproduce song lyrics Simon Willison’s Weblog · 1 day ago · 3

Anthropic’s new Fable release is cheaper, less restrictive TechCrunch · 2 days ago · 42 Developing Enterprise Frontier Safeguards with our customers Anthropic · 13

GPT-5.6 Is Last in 5.x Line, GPT-6 Coming in About a Month X · 1 month ago · 32

Q3 2026

◆ Anthropic released updated Claude Fable 5.1 and Mythos 5.1 models with revised pricing, access limits, and additional safety and watermark-detection features Model release

◆ Anthropic announced Enterprise Frontier Safeguards (EFS) to add customer-controlled zero data retention and automated misuse detection for its frontier models Feature update

◆ Anthropic adjusted Claude Code usage limits for Pro, Max, Team, and Enterprise accounts effective September 14 Feature update

• 3 Sep AI #184: Post Post Mortem
• 3 Sep Fable 5.1
• 2 Sep Claude's new system prompt really doesn't want to reproduce song lyrics
• 1 Sep Anthropic’s new Fable release is cheaper, less restrictive
• 1 Sep Developing Enterprise Frontier Safeguards with our customers
• 9 Jul GPT-5.6 Is Last in 5.x Line, GPT-6 Coming in About a Month

Relationships

Products & technology

• Anthropic develops this model · 2 sources
• Anthropic deploys this model · 2 sources
• Enterprise Frontier Safeguards (EFS) integrated with this model · 1 source