Sources & verification notes

Claude Fable 5.1

• Exact identifier & access

  Identity and lifecycle apply to this exact identifier and serving surface.

  • Model deprecations ↗Anthropic · provider-authored · checked Sep 13, 2026

• First availability

  Effective Sep 1, 2026. Checked Sep 13, 2026.

  • Introducing Claude Fable 5.1 and Claude Mythos 5.1 ↗Anthropic · provider-authored · checked Sep 13, 2026

• Availability status

  Effective date not established; this is an observation. Checked Sep 13, 2026.

  • Model deprecations ↗Anthropic · provider-authored · checked Sep 13, 2026

• Capabilities & limits

  Effective date not established; this is an observation. Checked Sep 13, 2026.

  • Models overview ↗Anthropic · provider-authored · checked Sep 13, 2026

• Input price

  Effective date not established; this is an observation. Checked Sep 13, 2026.

  Derived from the captured rate card's standard token row.

  • Pricing ↗Anthropic · provider-authored · checked Sep 13, 2026

• Output price

  Effective date not established; this is an observation. Checked Sep 13, 2026.

  Derived from the captured rate card's standard token row.

  • Pricing ↗Anthropic · provider-authored · checked Sep 13, 2026

• Model card

  Effective date not established; this is an observation. Checked Sep 13, 2026.

  • Models overview ↗Anthropic · provider-authored · checked Sep 13, 2026

• Official announcement

  Effective Sep 1, 2026. Checked Sep 13, 2026.

  • Introducing Claude Fable 5.1 and Claude Mythos 5.1 ↗Anthropic · provider-authored · checked Sep 13, 2026

• Provider description

  Effective date not established; this is an observation. Checked Sep 13, 2026.

  • Models overview ↗Anthropic · provider-authored · checked Sep 13, 2026

• Provider comparison

  Effective Sep 1, 2026. Checked Sep 13, 2026.

  • Introducing Claude Fable 5.1 and Claude Mythos 5.1 ↗Anthropic · provider-authored · checked Sep 13, 2026

• Full rate card

  Effective date not established; this is an observation. Checked Sep 13, 2026.

  • Pricing ↗Anthropic · provider-authored · checked Sep 13, 2026

• License

  Effective date not established; this is an observation. Checked Sep 13, 2026.

  Not verified. These sources establish the identifier, not this missing fact.

  • Model deprecations ↗Anthropic · provider-authored · checked Sep 13, 2026