🚨 HUGE NEWS: Claude now embeds an invisible watermark into every piece of text it generates.
Anthropic just documented how it works. Two marks, both machine-readable:
> Text: an imperceptible watermark woven into the words themselves. You can’t see it, and it doesn’t change meaning, quality, or readability.
> Files (.svg, .png, .jpg): signed provenance metadata on the C2PA open standard, so you can tell if a file’s been tampered with.
The watermark is applied at the model level.
That means it shows up no matter where the text comes from: the API, Claude, Claude Code, Cowork, Claude Tag, and even when a supported model runs through AWS, Google Cloud, or Microsoft Foundry.
Models launched on or after August 2, 2026 mark from day one. Older models are getting it during a transition period.
Every sentence Claude writes for you now carries a signature you’ll never see.