Reference

Structured, data-led reference tables generated directly from this site's facts module — an all-models pricing table, per-model specs, the retirement calendar, the plans explainer, a dated log of what changed, the minimum-cacheable-prefix table, effort-level definitions, migration diffs between generations, and side-by-side model comparisons. Unlike the how-to guides, these pages are intentionally short on prose and long on the actual numbers, because the value here is the table itself, not an essay around it. Every figure carries its own verification date; see /about/#accuracy for how that's maintained.

This cluster exists as a deliberate two-tier decision. Content that genuinely benefits from explanation — a migration story, a debugging walkthrough, the reasoning behind a cost trade-off — gets full prose in the how-to guides and cost guides. Content that is fundamentally a lookup — "what does Opus 5.5 cost per token," "when can Haiku 4.5 retire," "how does Sonnet 5.5 compare to Sonnet 4.6 on paper" — gets a short, dense table here instead, because padding a lookup out into paragraphs would make the answer slower to find, not more useful. A reference page links out to the relevant guide wherever the number alone doesn't tell the story.

If you only open two pages here, make them the all-models pricing table, which lists the cache-read rate beside every headline price now that the two no longer move together, and the minimum-cacheable-prefix table, the single table on this site that exists nowhere else.