OpenAI and Google back a shared robots.txt signal for AI training preferences
The proposal uses the __usage_ai-training token to reduce provider-specific rules, but it remains a voluntary draft and does not block crawling on its own.
R42 / SUMMARY
OpenAI and Google have announced support for a shared robots.txt signal that lets websites express preferences about the use of content for generative AI training. The mechanism uses the __usage_ai-training token, but it remains an Internet-Draft, is not fully implemented and does not replace crawler-specific controls.
KEY POINTS
- The __usage_ai-training token lets websites express a general path-based preference in robots.txt.
- OpenAI aims to implement the signal in the coming months, while Google targets 2027.
- The proposal is a developing Internet-Draft, not a final IETF standard.
- The signal concerns content use for training and is not a technical crawling block.
- Provider-specific controls such as GPTBot and Google-Extended remain relevant.
OpenAI and Google have announced support for a shared signal in robots.txt that lets websites communicate preferences about using their content to train generative models. Published on October 30, 2026, the proposal addresses a practical source of fragmentation: publishers currently need to identify crawlers and maintain separate rules for different companies.
The mechanism treats __usage_ai-training as a policy token in robots.txt. A website can use it to express a broad preference while making exceptions for specific paths. The Internet-Draft provides an example that rejects training across the site but permits it for a press-kit directory:
User-Agent: __usage_ai-training
Disallow: /
Allow: /press-kit/
The syntax is simple, but its effect needs careful interpretation. The token is not an access barrier, does not prevent copying by agents that ignore it and does not automatically change crawling behavior. It communicates a preference about a particular purpose: using content to modify the learned parameters of a generative model.
What OpenAI and Google have promised
OpenAI says it aims to honor the signal in the coming months. The company also says its existing controls will remain in place. Rules for GPTBot, which covers crawling that may be used for training, therefore remain separate from OAI-SearchBot, which makes pages eligible to appear in ChatGPT search results.
Google plans to support the signal in 2027. When the shared token expresses a preference against training and no explicit Google-Extended instruction is present, the company plans to interpret it as though Google-Extended had been disallowed. Website owners will still be able to use provider-specific rules to customize that choice.
This difference reveals an important consequence: a shared signal reduces operational work, but it does not make every provider’s policy identical. Each participant still needs to document when support begins, which products are covered and how the common preference interacts with proprietary settings.
A draft is not an approved standard
The specification was submitted by Kevin Kelley, identified in the document as affiliated with Anthropic, as part of work around AI usage preferences at the IETF. However, the text is still an Internet-Draft. It can be updated, replaced or allowed to expire, and does not by itself represent a final standard approved by the organization.
The draft also separates two ideas that are often combined. Rules aimed at a crawler concern automated access to pages. The proposed policy token concerns the intended use of content after it has been obtained. A provider may use the preference as a reason not to retrieve a page, but the document does not require the signal to operate as a traffic-blocking command.
In practice, administrators should not remove current configurations on the assumption that the new line already works. OpenAI maintains distinct controls for training and search, and Google will continue to offer Google-Extended. During the transition, the safer approach is to retain provider-specific rules and add the shared token only with a clear understanding of each provider’s documented behavior.
Interoperability improves, but the limits remain
The proposal’s significance lies less in creating a new right than in offering a common language. A small publisher could communicate one preference to several providers without tracking a growing list of bot names. Path-based exceptions would also make it possible to restrict articles while allowing a press kit, for example.
At the same time, robots.txt remains a public file of voluntary instructions, not authentication or copy protection. Its effectiveness depends on adoption and transparency from content consumers. The issue also sits within a wider dispute over how platforms use third-party materials, illustrated by the recent publisher response to Meta’s commercial terms.
The coordinated announcement signals technical convergence, but it does not resolve legal or economic questions about training. Until real implementations can be tested, the token is best understood as a promise of interoperability under construction: useful for expressing intent, but not sufficient as a website’s only control.
R42 / SOURCES CONSULTED
References used to verify facts and provide context for this story.
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Machine-Readable Training Preference Signal
IETF Datatracker
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Supporting a shared AI training control for websites
Google Search Central
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Google, Microsoft & OpenAI Plan To Honor Shared AI Training Opt-Out
Search Engine Journal
Gabriel Silva
Credited author of this story. Visit the profile for other publications.
R42 / FAQ
Does the new AI training signal already work with every provider?
No. OpenAI says it aims to implement the signal in the coming months, while Google targets support in 2027. Other providers can adopt their own timelines and interpretations.
What is the proposed robots.txt syntax?
The draft uses User-Agent: __usage_ai-training with path-based Allow and Disallow rules. Disallow: / expresses a preference against training on the entire site.
Does the signal stop bots from crawling a website?
No. Training-use preferences are separate from crawler rules. A website still needs to configure specific user agents if it wants to manage crawling.
Does the token replace GPTBot or Google-Extended?
Not immediately. OpenAI and Google say their provider-specific controls will remain available, including for making different choices about training, search and other uses.
Is the proposal already an official IETF standard?
No. The document published on October 30, 2026 is a developing Internet-Draft and may change before any final standardization.