From November 7, Grok's API quietly watermarks the text it writes. Here's what changes and how admins can turn it off
xAI's developer docs say that from November 7, 2026, text from grok-4.7, grok-4.6, grok-4.5, grok-4.3 and the grok-4.20 reasoning, non-reasoning and multi-agent models will carry an invisible statistical watermark by default. It covers the Responses and Chat Completions APIs, including structured outputs and tool-call arguments. xAI says it's for EU AI Act transparency rules, needs no code changes and doesn't affect quality or speed. Watermarked responses carry an x-watermark: true header, team admins can opt out per model in the Console, and access to the detection API is by application.
Why it matters
If you ship Grok-written text to customers or must meet EU AI Act rules, you'll want to know it's marked, and decide per model whether to keep it on.
Who it's for
Developers and team admins using the xAI API in products, especially those serving users in the EU.
What it means for you
- List which Grok models your app calls and check them against the models in xAI's watermarking doc.
- After November 7, log the x-watermark response header to confirm what's marked.
- If you need it off for a model, have a team admin change it in Console > Team settings > Model output watermarking.
Applies to: On by default for the listed models from November 7, 2026, at no extra cost. Opt-out is per model in Console > Team settings > Model output watermarking and takes effect within about 5 minutes. Detection is statistical and the detection API is by application only. Checked November 1, 2026.
Source: xAI docs on docs.x.ai
Written by AgentStackList from the original post. Checked Nov 1, 2026. Features, plans and availability can change, so confirm on the source before you rely on it.
xai-apiwatermarkeu-ai-actdevelopersgrok
More Grok Bot tricks
- Grok Bot on Mac can now read your texts, draft your emails and fill your calendar, with your OK app by app · Nov 12
- Grok Bot 1.0 turns your AI into a coworker: it sits in Slack and Teams, joins your calls and offers to pick up work before anyone asks · Nov 11
- Tell Grok Bot "grab me ice cream and chips for movie night" and Gopuff delivers it: checkout now happens inside the chat · Nov 11
- Grok Bot can now get inside your private network (safely): it joins your Tailscale tailnet to reach internal tools · Nov 10