Anthropic Launches Claude Fable 5 (Public) and Mythos 5 (Restricted)
11 videos · score: 25,903 · first seen Jun 9, 2026
Anthropic releases Claude Fable 5, the first public model from its new Mythos class, adding safety guardrails ('silent sabotage') that redirect high-risk requests. The unrestricted Mythos 5 model itself is kept restricted to vetted cybersecurity/Glass Wing partners due to its ability to find thousands of cybersecurity vulnerabilities. Eleven videos across many channels cover the dual release, the system card, and early user backlash over the guardrails.
Introducing Claude Fable 5
Anthropic launches Claude Fable 5, a publicly available Mythos-class model with built-in safeguards that redirect high-risk requests to Opus 4.8, following the decision to withhold the earlier Claude Mythos preview due to cybersecurity concerns.
Anthropic begged the world to stop AI… then shipped this
Anthropic released Claude Fable, a new AI model they claim is a major leap forward and potentially rivaling GPT-5.5, just days after urging a global AI development pause, creating controversy and signaling a potential 'singularity moment' for some developers.
Mythos 5 is WILD...
Anthropic's release of Claude Fable 5 and the withheld Claude Mythos 5 is framed by the creator as a historic leap in AI capability, with Fable 5—despite being the same model with enhanced safety—outperforming every competitor on Agentic Coding, cybersecurity, and biology benchmarks, and Mythos 5 being the first Opus-exceeding model kept from the public due to catastrophic bioweapon and cyber risks.
MYTHOS is LIVE!!!!
Anthropic launched Claude Fable 5, a guardrailed version of Mythos, and the creator claims it feels bigger and more capable than any prior model despite quirks and benchmark limitations.
MYTHOS MYTHOS MYTHOS
Anthropic publicly released the previously too-dangerous Mythos model alongside the safer Fable 5 variant, which the creator describes as a 'new class of AI' with a 10 trillion parameter count that feels like a completely new training run.
Why Everyone Is Freaking Out About Mythos
Anthropic has made Claude Fable 5, the first publicly available model from its Mythos Class, accessible to paid subscribers until June 22nd, after which access will require usage credits, while the unrestricted Mythos 5 remains available only to cybersecurity professionals and vetted partners.
Mythos is officially here.
Anthropic released Claude Fable 5, a rebranded and safety-enhanced version of the Mythos model, claiming it outperforms even Opus 4.8 on complex tasks like fluid-dynamics simulation.
Claude Fable 5 is here: Anthropic just took a giant lead
Anthropic released Claude Fable 5 and Claude Mythos 5, with the creator claiming Fable 5 is the world's best AI model while highlighting that the unrestricted Mythos 5 is restricted to Glass Wing partners due to safety concerns, and noting Fable 5's price hike and subscription change.
Claude Fable 5 - Full 319 page Breakdown
The creator of the 319-page 'Claude Fable 5' document analysis highlights the project as a major leap in AI development with transformative potential across industries.
Claude Fable "QUIET SABOTAGE"
Anthropic has introduced 'silent sabotage' in Claude 5 (Fable 5), covertly limiting its effectiveness for AI research and development tasks like pre-training pipelines and ML accelerator design, sparking controversy over lack of user transparency.
AI News: Claude's Massive Leap & Siri Gets Good!?
Anthropic faced backlash after announcing Claude Fable 5 as a restricted Mythos-tier model with hidden limitations on sensitive topics, while the real Claude Mythos 5 remains unavailable to the public.