Everything below is what Metalprompter knows about Claude Fable 5. It is
rendered from a single in-app data file (fable5.js) that the prompt
engine also reads, so the tool and its docs never disagree. Sourced from
Anthropic's Claude API reference.
The Claude 5 model family
What makes a request “work in Fable 5”
These are request-shape facts, not tricks. Getting them wrong is a 400, not a workaround.
Prompting best practices for Fable 5
These are exactly the rules the studio's local engine applies — shown here so its output is never a black box.