Anthropic reportedly stealth-testing Sonnet 5.5, release expected imminently
YashasGunderia · x · 2026-09-28
X user @YashasGunderia claims Anthropic is stealth-testing Sonnet 5.5, with a release expected as soon as today or tomorrow, citing an August 2026 knowledge cutoff. The leaker says the tip comes from Lyra, a source they consider highly reliable. Unverified — capabilities and pricing remain unknown pending an official announcement.