Anthropic released Claude Fable 5, its most capable Mythos-class model, with new safeguards that silently limit the model's effectiveness for requests related to frontier LLM development without notif…
Anthropic rolled back covert capability limits on its newly released Claude Fable 5 model after AI researchers and developers accused the company of "secret sabotage." The restrictions, buried in the …
Anthropic shipped Claude Fable 5, its first Mythos-class model, this week, posting a more than 10% benchmark improvement over Opus but blocking prompts related to cybersecurity, biology, chemistry, an…
Anthropic Chief Product Officer Mike Krieger used a thread on X to frame the company's June 9 launch of Claude Fable 5 as a product test, asserting the model can handle longer delegated tasks while th…
Anthropic released Claude Fable 5 and Claude Mythos 5 on June 9, 2026, both belonging to a new "Mythos-class" tier above the Opus class in capability. The two models share the same underlying architec…
Anthropic implemented silent safeguards in its Claude Fable 5 model that secretly degrade responses to queries about competing AI development, including ML accelerator design and pretraining pipelines…
Anthropic's Claude Fable 5 model automatically routes biology, cybersecurity, and distillation queries to Opus 4.8 for deeper evaluation, introducing a more aggressive safety classifier than previous …
Anthropic released Claude Fable 5 at $10 per million input tokens and $50 per million output tokens, positioning the model in the premium tier for high-capability reasoning tasks. The model is current…
Claude Fable 5 leads GPT 5.5 in coding benchmarks, long-horizon tasks, and multi-step reasoning, making it the stronger choice for agentic workflows and production use cases. GPT 5.5 excels in multimo…
Anthropic released Claude Fable 5 and Claude Mythos 5, two new large language models with a 1 million token context window and 128,000 maximum output tokens, priced at $10 per million input tokens and…
Simon Willison released version 0.32a3 of his LLM command-line tool on June 9, 2026, with the new release almost entirely written by Anthropic's Claude Fable 5 model. The update adds features to both …
Anthropic released Claude Mythos 5, the most powerful AI model in the world by every major benchmark, but standard users will not have direct access to it. Instead, consumers will use Claude Fable 5, …
Anthropic gave stripe early access to Fable 5, which migrated a 50 million line Ruby codebase in one day — a task that would have taken a full engineering team over two months. The model Anthropic act…
Simon Willison reverse-engineered the AgentsView tool to set a custom price for the newly released Claude Fable 5 model, which was not yet included in the platform's pricing database. The workaround a…
Anthropic launched Claude Fable 5, its most powerful and autonomous AI model to date, now available in Kilo. The model can independently self-prompt, browse, write code, test outputs, and navigate ope…
Anthropic released Claude Fable 5, the first publicly available version of its Mythos model, which University of Pennsylvania AI researcher Ethan Mollick used to generate fully playable video games fr…
Anthropic released Claude Fable 5, its most capable Mythos-class model, on Snowflake Cortex AI in private preview on the same day as the launch. The model is designed for complex, multi-step enterpris…
Anthropic released Claude Fable 5 on Tuesday, its first "Mythos-class" model, but restricted its ability to answer queries on cybersecurity, biology, and chemistry to prevent malicious use. The public…
AI researcher Andrej Karpathy said he feels demand for software growing substantially as working software becomes more accessible, citing the Jevons paradox. He noted users can now request explainers,…
Anthropic released Claude Fable 5, the first generally available Mythos-class intelligence model, and early testers found it crushes benchmarks but is conservative on execution. The model introduces s…