Computational Model Studio · Model release

Claude Fable 5.1

Demanding reasoning and long-horizon agentic work with text responses.

Developer: Anthropic · Last verified:

What it is designed to do

Demanding reasoning and long-horizon agentic work with text responses.

Primary contribution
inference planning
Input
text, image
Output
text (generated text response)

Documented uses: Demanding reasoning and long-horizon agentic work with text responses.

Access and deployment

  • Claude Fable 5.1 Anthropic API — available. Provider account and API access under the publisher’s current service rules. Offering documentation Complete provider service terms were not reviewed for this offering.
    • provider hosted: Use exact provider model ID claude-fable-5-1 with an eligible account and supported API endpoint. Limits: No local hardware requirement or weight-download claim is inferred from this API offering..
Technical profile and review notes
Construction
learned
Representation
neural
Normalized architecture tags
No normalized architecture tag assigned
Lifecycle
active

Inclusion rationale: The publisher recommends Fable for demanding reasoning when Opus at higher effort falls short, a material current choice for comparison.

Limitations

  • The reviewed publisher source establishes the listed task and modalities, not independent accuracy or reliability measurements.
  • Provider API access does not establish downloadable weights or local hardware feasibility.

Sources and related Studio records

Sources

  1. Claude models overviewAnthropic · checked 2026-10-04

Connections