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On 2026-06-09 @bcherny says Fable 5 is now available in Claude Code and Cowork…

2026-06-09 · 17:42 UTC ·@bcherny ·0 min read

Brief

Fable 5 is now available in Claude Code and Cowork (announced 2026-06-09). @bcherny asserts it’s markedly superior for coding—needing fewer prompts, improving token efficiency and code quality, enhancing tool use and self-verification, and enabling longer, more autonomous sessions. Anthropic markets it as “Claude Fable 5,” a Mythos-class model made safe for general use and surpassing earlier public Claude models.

Why it matters

On 2026-06-09 @bcherny says Fable 5 is now available in Claude Code and Cowork and calls it “the best model I have used for coding, by a wide margin.”

Key details

  • Claims about Fable 5: requires fewer prompts/steers, uses tokens more efficiently, produces higher-quality code, uses tools better, performs more intelligent self-verification, supports longer-running sessions, and offers greater trust and autonomy.
  • Anthropic/Claude labels the release “Claude Fable 5,” a Mythos-class model made safe for general use and described as exceeding capabilities of any previously generally available Claude model.
Source evidence

Fable 5 is now available in Claude Code and Cowork

Fable is the best model I have used for coding, by a wide margin. It is a big step up, enabling less prompts and steers, more efficient token use, better code quality, better tool use, more intelligent self-verification, longer running sessions, and higher trust & autonomy.

Happy coding!

Claude (@claudeai)

Introducing Claude Fable 5: a Mythos-class model that we’ve made safe for general use.

Its capabilities exceed those of any model we’ve ever made generally available.

Video

— https://nitter.net/claudeai/status/2064394146916229443#m