Claude Fable 5 and Mythos 5: Anthropic launches a new frontier model with safeguards and trusted access
Anthropic announced Claude Fable 5 for broad availability and Claude Mythos 5 for a restricted trusted-access program, with safety fallbacks to Opus 4.8 and new rollout/pricing details.
Editorial Team
The Authority AI Tools editorial team maintains this directory using vendor documentation, dated source checks, product changelogs, and clearly identified hands-on observations where available.
Anthropic announced Claude Fable 5 and Claude Mythos 5, positioning them as a new “Mythos-class” frontier model release with a split between broad availability (Fable) and restricted trusted access (Mythos). (https://www.anthropic.com/news/claude-fable-5-mythos-5)
What Anthropic launched
Claude Fable 5 (broad availability)
Anthropic says Claude Fable 5 is “available everywhere today,” and that on the Claude API and consumption-based Enterprise plans, Fable 5 is “fully available from today.” (https://www.anthropic.com/news/claude-fable-5-mythos-5)
For subscription plans, Anthropic describes a staged rollout window: through June 22 it’s included on Pro/Max/Team/seat-based Enterprise “at no extra cost,” then starting June 23 it “will require usage credits,” with a goal to restore it as a standard subscription offering “when sufficient capacity allows.” (https://www.anthropic.com/news/claude-fable-5-mythos-5)
Claude Mythos 5 (restricted trusted access)
Anthropic says Claude Mythos 5 is restricted to Project Glasswing partners (with cyber safeguards lifted) and “soon” to select biology researchers (with biology/chemistry safeguards lifted) until a broader trusted access program is available. (https://www.anthropic.com/news/claude-fable-5-mythos-5)
Anthropic also says users with access to Claude Mythos Preview can upgrade to Mythos 5 “beginning today.” (https://www.anthropic.com/news/claude-fable-5-mythos-5)
Safety safeguards and fallback to Opus 4.8
Anthropic says Fable 5 ships with safeguards that can route requests related to cybersecurity, biology and chemistry, or distillation to Claude Opus 4.8 instead, and that users will be informed whenever this happens. (https://www.anthropic.com/news/claude-fable-5-mythos-5)
Pricing and API model name
Anthropic lists pricing for Fable 5 and Mythos 5 as $10 per million input tokens and $50 per million output tokens, and says developers can use claude-fable-5 via the Claude API. (https://www.anthropic.com/news/claude-fable-5-mythos-5)
Source
- Anthropic — “Claude Fable 5 and Claude Mythos 5”: https://www.anthropic.com/news/claude-fable-5-mythos-5
Free Resource
2026 AI Coding Tools Comparison Chart
Side-by-side comparison of features, pricing, and capabilities for every major AI coding tool.
No spam, unsubscribe anytime.
Frequently Asked Questions
What is Claude Fable 5 and Mythos 5: Anthropic launches a new frontier model with safeguards and trusted access?
Related Articles
Cursor discloses malicious Claude Code extension in its VS Code marketplace
Cursor says a modified Anthropic.claude-code 2.1.313 extension was available for part of October 29; potentially affected users should follow Cursor's official response.
Read more →Product UpdatesOpenAI adds monthly API credits for eligible Pro and Business plans
Eligible ChatGPT Pro and Business subscribers can claim promotional API credits, with plan-specific amounts and a $500 monthly cap for Business workspaces.
Read more →Product UpdatesGoogle releases the Gemini API CLI in beta for agents and CI
The stateless Gemini API CLI lets coding agents, scripts, and CI pipelines use the Interactions API for generation, file analysis, and managed agents.
Read more →