01 · Operator
Who operates FDSE robot
- Company
- xav.com
- Type
- Other bot
- Official docs
- the-art-of-web.com
02 · Behavior
What FDSE robot does
Site owners install FDSE to add search to their own or remote sites. Its crawler fetches pages to build that search index. Each installation is run by a different site owner.
03 · Impact
Why FDSE robot matters for your site
If you allow it
- May index your pages for a site that links to you
If you block it
- No traffic from a major search engine
- Old software with no central operator
04 · Allow
How to allow FDSE robot
robots.txt
User-agent: FDSE
Allow: /Cloudflare
# Security › WAF › Custom rules › Create rule
Expression: (http.user_agent contains "FDSE")
Action: Skip › All Super Bot Fight Mode rules
# Also check Security › Bots: "Block AI bots" can block it regardless of robots.txt.WordPress
# WordPress serves a virtual robots.txt. Edit it with your SEO plugin:
# Yoast: SEO › Tools › File editor · Rank Math: General Settings › Edit robots.txt
User-agent: FDSE
Allow: /nginx
# nginx serves every user agent by default.
# Make sure no rule like this blocks it:
# if ($http_user_agent ~* "FDSE") { return 403; }Apache
# Apache serves every user agent by default.
# Make sure .htaccess has no rule like this:
# RewriteCond %{HTTP_USER_AGENT} FDSE [NC]
# RewriteRule .* - [F,L]05 · Block
How to block FDSE robot
Start with robots.txt. If FDSE robot keeps showing up in your logs, block it at your CDN or web server.
robots.txt
User-agent: FDSE
Disallow: /Cloudflare
# Security › WAF › Custom rules › Create rule
Expression: (http.user_agent contains "FDSE")
Action: BlockWordPress
# WordPress serves a virtual robots.txt. Edit it with your SEO plugin:
# Yoast: SEO › Tools › File editor · Rank Math: General Settings › Edit robots.txt
User-agent: FDSE
Disallow: /nginx
# In your server { } block:
if ($http_user_agent ~* "FDSE") {
return 403;
}Apache
# .htaccess
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} FDSE [NC]
RewriteRule .* - [F,L]
</IfModule>06 · User agents
User agents we see for FDSE robot
The operator does not publish a full user agent string. Requests contain the token “FDSE”.
07 · Verification
Is it really FDSE robot?
FDSE robot’s operator publishes no IP ranges or hostnames, so requests cannot be verified. Treat the user agent as a claim, and watch your logs for unusual request rates.
FAQ
Questions about FDSE robot
What is FDSE robot?
It is the crawler of FDSE, a search engine script for local and remote sites from xav.com.
Should I block FDSE robot?
It is usually harmless. Block it if it causes unwanted load.
Last reviewed Oct 7, 2026