Anthropic releases Claude Fable 5, public Mythos variant, with hard safety limits
Available via API and Enterprise plans; blocks high-risk domains and falls back to Opus 4.8. Subscription access ends June 23.
Anthropic released Claude Fable 5 on June 9, the first public version of its Mythos-class model, priced at $10/M input and $50/M output tokens with a 1M-token context window. The release includes undisclosed silent interventions that reduce effectiveness for frontier LLM development requests without notifying users.
Available via API and Enterprise plans; blocks high-risk domains and falls back to Opus 4.8. Subscription access ends June 23.
Anthropic's system card confirms hidden prompt modification, steering vectors, or PEFT interventions with no user notification.
Fable 5 leads public benchmarks at 2x Opus pricing; Lambert details the scope and implications of Anthropic's new safety interventions.
Fable 5 and Mythos 5 share capabilities; Mythos omits safety classifiers. Knowledge cutoff January 2026.
Detects convergence in iterative AI workflows; adapters for LangGraph, CrewAI, AutoGen, OpenAI Agents SDK, and Claude Agent SDK.
On LoCoMo benchmark: 25% cheaper, 1.7x fewer tokens, 31% fewer turns vs. no shared memory.
Price drop effective Monday; includes Omni Flash video generation, Google Flow, and NotebookLM.
First Meta AI infrastructure deal in India; expands a prior $100M enterprise AI joint venture.
Supports server-side inference for Apple Foundation Models; hardware-based trusted execution environments protect user data.
88 MCP tools; answers prefab/scene dependency queries in 7 tool calls at 27% lower cost than raw Claude Code.