Fable 5.1
Fable 5 spent most of June under U.S. export controls — pulled June 12, restored globally on July 1 after Washington relented. The successor landed on schedule: Fable 5.1 shipped on Sep 1, alongside Mythos 5.1. The list price did not move — still $10/$50 per million — while cache reads fell 75% to $0.25, which Anthropic puts at ~25% lower real cost and up to ~45% on agentic work. The whole saga is chronicled day-by-day on our sister site FableWatch — and the moment the next Fable answers on the public API, ArtificialWatch fires.
Leaks & news, newest first.
Anthropic: Opus 5.5 performs at Fable 5.1’s level on most work
Anthropic released Claude Opus 5.5 and says it “performs at the level of Claude Fable 5.1 on most work,” at $4/$20 per million tokens against Fable 5.1’s $10/$50. The announcement makes no change to Fable 5.1’s availability or price. via Anthropic
Mythos 5.1 opens to verified life-science teams
Anthropic’s new Life Sciences Verification Program gives vetted researchers access to its Mythos, Opus and Sonnet models under safeguards more permissive for biology work. Standard Use grants cover Mythos 5.1 now; high-risk grants for Mythos stay limited to a small set of entities while Anthropic works with the US government to widen them. via Anthropic
Claude Fable 5.1 is live — and Mythos 5.1 with it
Anthropic released Fable 5.1 and Mythos 5.1. Fable 5.1 is on the Claude API as claude-fable-5-1, plus AWS, Google Cloud and Azure; 1M context, 128K output, effort selectable low → max. The sticker price is unchanged at $10/$50 — but cache reads fell 75%, $1.00 to $0.25 per million, which Anthropic puts at roughly 25% lower cost on typical work and up to 45% on complex coding and heavily agentic tasks. Our sweep saw the id at 17:52:22 UTC and confirmed it 60 seconds later. via Anthropic
Reports: Fable shifting in the Claude subscription pickers
Users are reporting Fable-tier changes inside Claude consumer subscriptions — unconfirmed by Anthropic, and exactly the surface our subscription watch monitors. If a model leaves a picker you pay for, that's an alert, not a surprise.
Fable 5 returns to general availability, worldwide
Anthropic restored Fable 5 to users globally across the Claude Platform, claude.ai and Claude Code — ending the 19-day export-control freeze that began June 12. via Anthropic release notes
Washington moves to lift the Fable 5 export limits
POLITICO reported the administration planned to remove export restrictions on Fable 5 as early as that evening, per two officials — clearing the way for general users again. Mythos 5 had already been partially lifted for vetted partners on June 26. via POLITICO
Export controls land on Fable 5 and Mythos 5
The suspension that started it all — both mythos-class models pulled from general availability under U.S. export controls. Our sister site FableWatch was born to track it, sourced and newest-first. via FableWatch
The official word.
"Claude Fable 5.1 is available today on all platforms, including Amazon Web Services, Google Cloud, and Microsoft Azure. Developers can get started with claude-fable-5-1 on the Claude API."
Anthropic, “Introducing Claude Fable 5.1 and Claude Mythos 5.1” · Sep 1, 2026
$10 / $50 per million tokens, on Anthropic's own API.
How much does Fable 5.1 cost?
Anthropic's own API lists Fable 5.1 (claude-fable-5-1) at $10 per million input tokens and $50 per million output tokens, and $0.25 per million cached input tokens. Prices as published in the models.dev catalog, as of 2026-10-06.
What is Fable 5.1's context window?
1M tokens, with up to 128K output tokens per response, as Anthropic lists Fable 5.1 (claude-fable-5-1).
Listed by 30 providers, exact ids below.
30 providers list Fable 5.1 in the models.dev catalog (as of 2026-10-06), under the model ids shown below.
claude-fable-5-1anthropic.claude-fable-5-1 · global.anthropic.claude-fable-5-1 · us.anthropic.claude-fable-5-1claude-fable-5-1@defaultclaude-fable-5-1@defaultclaude-fable-5-1claude-fable-5-1anthropic/claude-fable-5.1anthropic/claude-fable-5.1claude-fable-5-1claude-fable-5-1anthropic/claude-fable-5.1anthropic/claude-fable-5-1Also listed by DevPass (LLM Gateway), DigitalOcean, Eden AI, GitHub Copilot, GitLab Duo, Kilo Gateway, LLM Gateway, Merge Gateway, NanoGPT, Neon, Ofox, OpenCode Zen, Opper, Requesty, Tempr Gateway, Venice AI, Vivgrid, ZenMux.
Listings cover the model family, so a provider may list a sibling tier under the same name. Check the id before you build on it.
Head to head, on the public leaderboards:
Hear it the second Fable 5.2 answers.
Fable 5.1 landed Sep 1 — we called it 60 seconds after it answered. We sweep Anthropic's public API every 60 seconds, and the moment the next Fable returns a real answer, your channels fire — email + Chrome push free, SMS and a phone call on paid tiers. Pro also watches the Claude subscription pickers between launches.