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← Back to all updatesPublished ·Anthropic• Minor
Claude Fable 5 runs safety classifiers on requests and during generation, returning refusal stop reasons.
The read
The important change is operational: refused work has a machine-readable stop reason and no charge before output.
The frame
For builders, the beta fallbacks parameter reruns refused requests on another model and bills at fallback rates.
Primary source
Anthropic →Keep reading
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