Released June 9, 2026
What is Fable 5? The Model That Compresses Months of Work into Days
The internal model class, now in your hands.
Fable 5 is the first publicly available model in Anthropic's Mythos class, a model family that was previously internal-only. This page covers what it is, what it does well, what it costs, and how to start working with it.
Your first Fable 5 project. 20 minutes. Not 20 hours.
Fable 5 is Anthropic's newest model, released June 9, 2026. It is the first publicly available model in the Mythos class (previously internal-only), with the same underlying capability as Claude Mythos 5 plus safety safeguards for public release. It is state-of-the-art at software engineering, knowledge work, vision tasks, and scientific research, and it costs $10 per million input tokens and $50 per million output tokens. It is free for Pro, Max, Team, and Enterprise subscribers through June 22, 2026.
Capabilities
What Fable 5 does well
The defining trait of Fable 5 is that performance scales with task length and complexity. The longer and harder the work, the more the model separates itself.
Software engineering
State-of-the-art on software engineering tasks. Stripe used Fable 5 to compress months of engineering work into days.
Knowledge work
State-of-the-art performance on knowledge work, with performance that scales as tasks get longer and more complex.
Vision tasks
Extracts data from scientific figures and rebuilds web apps from screenshots. Vision is a first-class capability, not an add-on.
Scientific research
State-of-the-art on scientific research tasks, from reading figures to long-context reasoning across large bodies of material.
Long-duration autonomous work
Performance scales with task length and complexity. Built for long-running autonomous work, not just quick exchanges.
Safety routing built in
Sensitive queries auto-route: cybersecurity questions go to Claude Opus 4.8, with bio/chem and distillation protections in place. Triggers in under 5% of sessions.
Long-Horizon Work
Built for tasks that take hours, not seconds
Most model comparisons focus on short benchmarks. Fable 5 is designed for the opposite end of the spectrum: long-duration autonomous work and long-context reasoning across millions of tokens. That means whole codebases, full research corpora, and multi-step projects that run without constant supervision.
The practical effect shows up in how teams use it. Stripe compressed months of engineering work into days. On the vision side, Fable 5 can extract data from scientific figures and rebuild web apps from screenshots, which turns visual artifacts into working starting points instead of dead ends.
This is why learning to work with Fable 5 matters: the model rewards people who can scope, delegate, and verify long-running work. Those are skills, and they can be learned.
Pricing
What Fable 5 costs
API Pricing
Subscriber Access
Free through June 22, 2026
Fable 5 is included at no extra cost for Pro, Max, Team, and Enterprise subscribers through June 22, 2026. If you have any of those plans, you can try it today.
Safety
How Fable 5 handles sensitive queries
The Mythos class was internal-only before this release. To make Fable 5 publicly available, Anthropic added safety safeguards on top of the same underlying capability as Claude Mythos 5.
In practice, certain sensitive queries are automatically routed: cybersecurity questions go to Claude Opus 4.8, and there are protections around bio/chem topics and model distillation. This routing triggers in under 5% of sessions, so for the vast majority of work you will never notice it.
Learn how to actually work with Fable 5
Reading about a model and being good with it are different things. The free Fable 5 course at Claude Academy walks you through scoping long-running tasks, working with vision inputs, and getting reliable results from a model that rewards clear delegation. Hands-on from the first lesson.
Frequently Asked Questions
What is Fable 5?
Fable 5 is an Anthropic model released on June 9, 2026. It is the first publicly available model in Anthropic's Mythos class, which was previously internal-only. It has the same underlying capability as Claude Mythos 5, with safety safeguards added for public release.
What is the Mythos class?
Mythos is a class of Anthropic models that was previously available only inside Anthropic. Fable 5 is the first Mythos-class model released to the public. It carries the same underlying capability as Claude Mythos 5, with additional safety safeguards for public use.
How much does Fable 5 cost?
Fable 5 API pricing is $10 per million input tokens and $50 per million output tokens. It is free for Claude Pro, Max, Team, and Enterprise subscribers through June 22, 2026.
Is Fable 5 free?
Fable 5 is free for Pro, Max, Team, and Enterprise plan subscribers through June 22, 2026. After that, standard plan access and API pricing apply ($10 per million input tokens, $50 per million output tokens).
How is Fable 5 different from Claude Opus?
Fable 5 belongs to the Mythos class rather than the Opus family, and its performance scales with task length and complexity, making it suited to long-duration autonomous work and long-context reasoning across millions of tokens. The two also work together: when Fable 5 receives certain sensitive cybersecurity queries, it automatically routes them to Claude Opus 4.8. That routing triggers in under 5% of sessions.
What is Fable 5 best at?
Fable 5 is state-of-the-art at software engineering, knowledge work, vision tasks, and scientific research. Its vision capabilities include extracting data from scientific figures and rebuilding web apps from screenshots. Stripe reported compressing months of engineering work into days with it.
Get hands-on with Fable 5 this week
The free course is open. Subscriber access is free through June 22.