Baidu · Other AI
YiyanBot
The product this token is named after no longer carries the name. 文心一言 ("Yiyan", the consumer brand over Baidu's ERNIE models) had `yiyan.baidu.com` as its front door; that hostname now 302s to `wenxin.baidu.com`, where the product is titled 百度文心助手 running 文心5.1 and the canonical `og:url` points at `chat.baidu.com`. Whether the crawler is genuinely distinct from `ERNIEBot` or the same fetcher wearing the consumer badge cannot be settled, because Baidu documents neither token and lists neither in its user-agent table: the split that third-party directories draw between the two is coherent and unattributable. A token named after a retired surface is a fair candidate for quiet deprecation, and equally fairly may persist untouched because changing a crawler's user agent breaks every robots.txt that references it; both readings are speculation, and only the redirect is verified.
- Operated by
- Baidu
- Purpose
- Other AI
- robots.txt token
- YiyanBot
- Verification
- User agent only
AI-adjacent traffic that does not fit the three purposes above.
How to verify YiyanBot
Baidu publishes no list of IP addresses for YiyanBot, so nobody (us included) can prove that a request carrying this user agent really came from Baidu. The name is trivial to copy. Treat it as a claim the visitor is making about itself, not as an identity anyone has checked.
There is no range list to confirm. This entry was last reviewed against Baidu's own documentation on .
User agent
Baidu has not published a full user-agent string for YiyanBot. Requests are identified by the YiyanBot product token appearing in the User-Agent header; we match that token rather than a whole string, because the rest of the header varies and matching it would miss real traffic.
robots.txt for YiyanBot
Block
User-agent: YiyanBot
Disallow: /Allow
User-agent: YiyanBot
Allow: /robots.txt is a request, not an enforcement mechanism. It is honoured by convention, and a crawler that ignores it is stopped at your edge, not in a text file.
What blocking YiyanBot costs you
No vendor statement exists to price this against. Structurally, if the token is live it would be serving retrieval for Baidu's consumer assistant, so what is at risk is being drawn on and cited in that assistant's answers for Chinese-speaking users: a genuine surface inside China, an irrelevance to a site with a Western-market audience. Since Baidu neither names the token nor commits to reading a rule addressed to it, an operator who writes one is buying a possibility rather than a control. Free to add, unverifiable in effect, and pointed at a brand Baidu has already moved on from.
Vendor documentation
Baidu does not publish documentation for YiyanBot that we could find. Everything on this page comes from what they do publish elsewhere and from observed behaviour, so treat it accordingly.