Independent reference · Mythos-class
Claude Mythos, documented — calmly and with sources.
A technical reference for Anthropic’s Mythos-class models: Mythos Preview, Fable 5, Mythos 5 and Project Glasswing. Explainers, comparisons, a glossary and live availability — original writing, every fact linked.
Start here
Six pages that orient you
- What is…
What is Claude Mythos?
Claude Mythos is Anthropic's Mythos-class AI model tier — the level above Opus. What the large language model covers, who can use it, and its status. - What is…
What is Claude Fable 5?
Claude Fable 5 is the public, safeguarded edition of Anthropic's June 2026 Mythos-class model. Same model as Mythos 5, with safety classifiers. - Availability & status
Is Claude Fable 5 available?
Whether Claude Fable 5 is available right now depends on live data — Anthropic's status page drives the verdict. Here's the context and where to check. - Comparisons
Fable 5 vs Mythos 5: Same Model, Different Safeguards
Fable 5 and Mythos 5 share one underlying model — the only real difference is safeguards. Here's what changes and which edition you'd actually use. - Project Glasswing
Project Glasswing, Explained
A plain-language overview of Project Glasswing: Anthropic's restricted program for Mythos-class access, who it serves, how it's priced, and its current status. - Specs & benchmarks
Fable 5 Pricing: $10/$50 per Million Tokens Explained
Fable 5 pricing breakdown: $10 input / $50 output per million tokens after the intro window, free for Pro/Max/Team/Enterprise Jun 9-22, then usage-based.
Browse the reference
60 pages · 10 clusters
What is…
Plain-language explainers of the Mythos-class models and terms.
6Availability & status
Is it released? Is it suspended? Live-data status mirrors.
8Specs & benchmarks
Context, output, pricing, and how the numbers are sourced.
7- Claude Mythos benchmarks — what we actually know
- Claude Mythos Specs: Context, Output, Pricing & Retention
- Fable 5 Benchmarks: What's Confirmed and What Isn't
- Mythos 5 Context Window: 1M Tokens In, 128k Out
- Fable 5 Pricing: $10/$50 per Million Tokens Explained
- Mythos 5 Pricing: Reference Rates and Glasswing Preview
- Claude Mythos System Card: What It Is and Its Status
Access & preview
How to get in: Glasswing, previews, free windows.
5Safety & cyber
Classifiers, safeguards, export controls, the Fable angle.
6- Claude Mythos and Cybersecurity: Why Cyber Is a Covered Domain
- Fable 5 Safeguards: Classifiers, Reroute, and Covered-Model Status
- Fable 5 Classifiers: The Three Domains and How Reroute Works
- Why Is Mythos Restricted? Two Distinct Reasons Explained
- Mythos Export Control: The June 12, 2026 US Directive
- Fable 5 Distillation: Why It's a Classifier-Covered Domain
Comparisons
Side-by-side spec tables: Fable, Mythos, Opus, and rivals.
7- Fable 5 vs Mythos 5: Same Model, Different Safeguards
- Fable 5 vs Opus 4.8: Mythos-Class vs the GA Flagship
- Mythos vs Opus: Tier and Access, Side by Side
- Fable 5 vs GPT-5.5: A Cross-Vendor Reality Check
- Fable 5 vs Gemini 3.5: Cross-Vendor, Honestly Scoped
- Fable 5 vs Sonnet 4.6: Frontier Power vs Everyday Value
- Opus 4.8 vs Sonnet 4.6: The Practical GA Choice
Project Glasswing
The restricted-access program behind Mythos-class deployment.
4Rumors & leaks
What is real, what is mislabel, what people actually mean.
4Glossary
Defined terms for the Mythos vocabulary.
12FAQ
Aggregated answers to the most common questions.
1Featured comparisons
All comparisons →- Fable 5 vs Mythos 5: Same Model, Different Safeguards
- Fable 5 vs Opus 4.8: Mythos-Class vs the GA Flagship
- Mythos vs Opus: Tier and Access, Side by Side
- Fable 5 vs GPT-5.5: A Cross-Vendor Reality Check
- Fable 5 vs Gemini 3.5: Cross-Vendor, Honestly Scoped
- Fable 5 vs Sonnet 4.6: Frontier Power vs Everyday Value
Glossary
Full glossary →Breaking news and the canonical live verdict live on our sister desk, anthropicmythos.ai ↗. This site owns the durable reference layer.