Text watermarks are machine-readable but should be transparent to humans. “When a supported Claude model generates text, it weaves an imperceptible watermark directly into the text itself. This is done by the model itself, so it doesn’t matter whether you use the Claude API, Claude Code, Cowork or Tag. Note that the watermark will be applied to all text coming out of Claude models, even if the AI wasn’t the original author. But there are benefits for AI companies too – as more and more bots flood the Internet with comments and even whole articles, AI companies might find themselves training new AI models on text written by old AI models.