Anthropic moves the Bedrock watermark rollout date to 17 October

Published 9 October 2026

Anthropic's help article on how Claude marks generated content now says the text watermark rollout on Amazon Bedrock for Claude Fable 5, Opus 4.8 and Sonnet 5 will complete by 17 October. The same footnote said 12 October from 1 October, when it appeared, until an edit late on 8 October. Nothing else in the article changed[1].

What changed

The table headed "Which Claude models support watermarking" lists nine models with the text watermark on Anthropic's own surfaces and through the cloud partners AWS, Google Cloud and Microsoft Foundry. For three of them, Fable 5, Opus 4.8 and Sonnet 5, the cloud-partner tick carries a footnote. The copy we read on the morning of 8 October said "Rollout on Amazon Bedrock will complete by October 12." The live article, whose modification time is 23:39 UTC on 8 October, says "Rollout on Amazon Bedrock will complete by October 17." The footnote still gives no year and names no other cloud partner[1].

What it means

If you reach Fable 5, Opus 4.8 or Sonnet 5 through Amazon Bedrock, Anthropic's own statement is that their text may not yet carry the watermark, and the date by which it will has moved five days later. On Anthropic's own surfaces the three are listed as marked without a footnote, and marking applies wherever Claude is offered, worldwide[1]. The other six text-watermarked models carry plain ticks in the cloud-partner column[1]. What Anthropic marks, and how.

What is still not known

Anthropic does not say why the date moved, whether the rollout is partly complete, or whether the Google Cloud and Microsoft Foundry rollouts for these models are finished; the footnote names only Amazon Bedrock. The detector is still in private preview for organisations obliged to check under EU law, and Anthropic has published no detection accuracy figures[1]. What this means for developers.

Last verified against primary sources: 2026-10-09