EU AI Act’s Transparency Code, which took effect on August 2, requires AI companies to mark AI-generated or edited content in a way other systems can identify them.

Anthropic said that all models released after August 2 will automatically have tech to watermark both computer-generated text and files. For files, the company is using the C2PA open standard.

The company said it will extend support for older models as well, adding that the watermark will travel when users copy and paste the text.

“Because the watermark is part of the text, it will travel with the text when it’s copied and pasted elsewhere, and may persist through some editing. Watermarking will be applied at the model level, which means it will be present no matter which Claude product or surface the text comes from,” the support page reads.

It’s not clear how much editing users need to do to remove the watermark. We have asked Anthropic to clarify and will update the story if we hear back.

The company noted that watermarking will apply to different products like Claude platform API, Claude, Claude Code, Claude Cowork, and Claude Tag.

Platforms are now rushing to watermark AI-generated content after backlash from users and to avoid regulatory scrutiny. Last week, AI music platform Suno said it will mark tracks created on its platform after a spate of legal challenges. Last month, newsletter service Substack teamed up with Pangram to flag AI-generated content. The company’s CEO, Chris Best, called out Claudefishing, a term used for people using AI to generate content.

Apart from Anthropic, other companies like Black Forest Labs, Google, Meta, Microsoft, OpenAI, and Synthesia have committed to adhering to the EU’s code.