The US government used export-control authority to force Anthropic to recall its frontier AI models, Mythos and Fable 5, citing an unspecified concern with no statutory process or appeal. The author, …
Anthropic reversed course on secretly degrading responses for users seeking help with frontier AI development after a developer backlash, instead routing those requests to a less capable model and inf…
Anthropic released Fable 5, the public version of its Mythos AI model, on Tuesday with visible guardrails on cybersecurity and biology topics and a silent restriction on LLM creation capabilities that…
Anthropic released Fable 5 at double the cost of its predecessor Opus 4.8, charging $10 per million input tokens and $50 per million output tokens starting June 23, while OpenAI considers significant …
Anthropic's Fable 5 model has become the company's most "honest" model to date, frequently telling users it is being honest in its responses. A user who indexed 202,381 messages from local Claude Code…
Fable 5 has achieved a performance level on par with GPT-5.5 in the Artificial Analysis Coding Agent Index, a composite benchmark measuring real-world coding agent performance across software engineer…
Anthropic reversed its policy on Fable 5's guardrails after users objected to the model silently sabotaging projects instead of issuing clear refusals. The company amended the policy to provide visibl…
Fable 5 will be removed from Claude Code on the 22nd, ending its inclusion in the platform's bundled tools. The game will remain available for purchase separately, though its removal from the integrat…
Frontier AI models have consistently improved in intelligence over time, with Anthropic's Fable 5 (Mythos 5) now demonstrating gamechanging performance for software engineering tasks. Open-weight mode…
Anthropic's 2026 Claude model lineup includes four tiers — Fable 5, Opus, Sonnet, and Haiku — each designed for specific task complexities and cost profiles. Teams that implement intelligent model rou…
Anthropic released its Fable 5 AI model on Tuesday with strict safety guardrails that blocked many harmless queries, including questions about cancer research and public figures, triggering widespread…
Benchmarks comparing AI models consistently pit Fable 5 against GPT 5.5 xhigh, but a user argues this is an unfair matchup because GPT 5.5 Pro, which has been available for some time and outperforms O…
A developer shipped a fully-tested, security-audited authentication system for HandyFEM, a marketplace app for women in the skilled trades, using a comprehensive code review process that caught 10 cri…
Anthropic updated its Fable 5 AI model on Wednesday to notify users when their requests are downgraded or rejected for national security reasons, following backlash over the company's initial silent i…
Anthropic apologized for a hidden guardrail in its Fable 5 AI model that silently sabotaged users' attempts to train other AI systems, and announced it will make the safeguard visible. The company ack…
Anthropic reversed a policy that would have allowed its Claude AI model to silently limit effectiveness for researchers working on frontier AI development, following widespread backlash. The company a…
Anthropic has introduced a two-tier model strategy with Mythos 5 and Fable 5, both running the same Claude 5 base model but with different safety guardrails. Fable 5, available to general API users an…
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…
Fable 5, the public version of the Mythos AI model, has been released with significant capabilities but raises concerns over new precedents it sets. The model's deployment highlights ongoing debates a…
AWS Bedrock customers using Anthropic's Mythos-class models, including Fable 5 and Mythos 5, must now consent to 30-day data retention by Anthropic for misuse detection, with data leaving AWS's securi…