The company says supported new Claude models will embed machine-readable watermarks in generated text, while supported files can carry signed provenance metadata. What Claude Will MarkAnthropic says Claude models launched in the EU on or after August 2, 2026 support machine-readable marking from launch. Anthropic says it therefore applies across supported Claude products, including its API, Claude, Claude Code, Claude Cowork and Claude Tag. That makes the immediate significance less about suddenly being able to identify every AI-written sentence and more about establishing infrastructure for content provenance. For now, Anthropic’s announcement marks another step toward that model: AI content may no longer need to announce itself visibly, but its origin could increasingly be designed to remain machine-readable.