Primary
- Claude Fable 5 and Claude Mythos 5 — Anthropic, 2026-06-09. The announcement. Source for every benchmark claim, partner quote, safeguard description, availability date, and chart on this site.
- platform.claude.com/docs — the API reference. Source for model ID, parameters, the 400-causing changes, caching minimums, and beta headers. Always newer than us — verify here before shipping code.
- Models overview — current model IDs, context windows, and pricing in one table.
Secondary
- Discussions & coverage — our curated HN threads and press, each annotated.
- The video charts — the top 20 YouTube takes, ranked by learning value.
How this site handles facts
- Numbers come from the announcement or the API docs — never from model memory or other people's summaries.
- Charts are hot-linked to Anthropic's originals, not redrawn — redrawing introduces errors.
- Date-sensitive facts (the June 22 subscription window) are flagged inline and tracked in News.
- Machine-readable twins of every fact set live in /api/ with a
last_verifieddate.
Moral: a guide is only as good as its bibliography. Ours is short on purpose.