AI THREAT TRACKER / EV-041 · Model release

Anthropic launches Claude 4

Hybrid reasoning models target longer coding and agent tasks.

Model labAnthropic

TopicsModel release

OCCURRED22 May 2025

PUBLIC ACCOUNT22 May 2025

EVIDENCEFirst-party account

About these dates

Date of the original developer release announcement.

Anthropic launched Claude Opus 4 and Sonnet 4 as one model generation, combining immediate responses with extended thinking. The developer described improvements in coding and sustained agent work; the two models had different access tiers. Anthropic ↗

Sources & attribution

Organizational disclosure 22 May 2025
claude 4 release announcement ↗
Anthropic. Original developer announcement.