Anthropic Claude API — Claude Sonnet 5.5 — Event History

Anthropic's official 2026-10-07 Claude Haiku 5.5 announcement states Sonnet 5.5 cache-read rate fell from $0.20 to $0.10 per 1M cached tokens effective 2026-10-07 (native USD, same route and metric, -50%). Base input/output rates remain $2/$10 per 1M. Older Sonnet launch page and Claude Platform pricing docs still show $0.20; newer dated announcement used as authority, with discrepancy recorded in canonical Resource Notes.

New canonical AI API resource. Official Anthropic docs verify active status, 1M-token context, and standard pricing of 2 USD/MTok input, 10 USD/MTok output, and 0.20 USD/MTok cache reads.