Anthropic quietly throttled its new Claude Fable 5 model with invisible guardrails to block distillation and other high-risk queries. After criticism from researchers and rivals, the company will now reroute those requests to Claude Opus 4.8 and clearly notify users each time a safeguard triggers.

This roundup covers Google’s Gemini 3.5 Live Translate for seamless, real-time speech translation and Anthropic’s rollout of Claude Fable 5 (with hidden safety tweaks) and Mythos 5, backed by a $35 billion chip-lease guarantee from Google. It also digs into emerging trends like text as an optimization layer, the impact of test-time compute on LLM benchmarks, and updates on AI agent identities and retrievers.

Simon Willison runs Claude Fable 5 through its paces, finding it slower and pricier than Opus 4.8 but far more knowledgeable thanks to its 1 million-token context. He tests it on real-world coding tasks—upgrading a MicroPython sandbox to full CPython in WASM and adding pause-resume hooks to Datasette Agent—showing it can build complex features end-to-end.

The author tests Anthropic’s Mythos-class model, Claude 5 Fable, on tasks from epic poems to complex isochrone maps and research calibration software. Fable autonomously delegates work to cheaper agents, executes multi‐hour workflows, and produces sophisticated outputs, but its decision process remains a black box, shifting the user’s role from hands‐on builder to outcome judge.