Yahoo! JAPAN

This guide covers the prompting and scaffolding patterns specific to Claude Fable 5 and Claude Mythos 5. For the model's specifications, pricing, ...

Behavioral differences and prompting patterns for Claude Fable 5.1 and Claude Mythos 5.1, covering effort, progress updates, tool-call batching, ...

2026/6/11 -Try claude update at the command prompt and then running it again. If not, /model claude-fable-5[1m] will work even with an older version.

2026/9/1 -Select Fable 5.1 explicitly: run /model fable, or launch with claude --model fable. Fable 5: /model claude-fable-5 or claude --model claude- ...

Claude Mythos 5.1 offers the same capabilities only to organizations verified through Anthropic's verification programs, such as the Cyber Verification Program.

2026/9/15 -The /model picker in Claude Code. Effort defaults to high here, and ... claude --model fable --effort high. Now, switching Fable on is ...

2026/6/11 -First practical detail: you need Claude Code v2.1.170 or later. Older versions simply won't show Fable 5 in the model picker. Run claude ...

I encourage everyone to please upload their fable-5 traces from whatever harness they may have used. This is all valuable data and we need to pool it together ...

Run /model fable , or /model claude-fable-5 to pin the exact ID. If it is missing from the picker, run claude update . How to change Claude Code model to Fable ...