Anthropic Watermarks Four Claude Models for EU Compliance — Here's How It Works

Anthropic applied an invisible text watermark to Mythos 5, Opus 4.7, Opus 4.6, and Sonnet 4.6 on Tuesday, using a technique based on Google DeepMind's SynthID-Text — the watermark nudges word choices during generation using a secret key, survives copy-paste and light editing, and can't be seen by readers, but the detection API is currently only available to regulators and researchers. Also: thirty-three of forty-one data center ballot measures passed Tuesday, with Goldman Sachs flagging forty-five percent of planned US capacity at risk, and Apple's 10-K expanded its AI agent risk disclosure to six hundred words, warning that agents may act on systems they're not authorized to reach.