On Tuesday, 11 August, Anthropic confirmed a change this column has been expecting for a while: text generated by its newest Claude models now carries an invisible watermark, woven into the words themselves, everywhere Claude is used, worldwide. Supported files such as images get a signed provenance label on top, under the industry C2PA standard. The trigger is European law — the EU AI Act’s transparency rules became enforceable for newly launched AI systems on 2 August — but rather than run a separate European version, Anthropic is applying the marking globally.

Nor is this a Claude quirk. OpenAI, Google, Microsoft, and Meta have signed the same European code of practice, and platforms have begun flagging AI content on their own initiative. The direction is settled: AI-generated content is becoming identifiable. Any business that has built AI into its weekly routine, as this column has been encouraging for ten weeks, should understand what that means before the detection tools land in other people’s hands.

New Claude models watermark their text at the model level, wherever Claude is used — withsigned provenance labels on files beyond text. (Branded graphic by PGH Consulting, LLC)