Manus-User user agent
Operated by Butterfly Effect
Manus-User is the user agent reported for Manus, a browser-based AI agent that completes tasks on websites.
The Manus-User bot at a glance
- Manus-User is operated by Butterfly Effect and loads web pages in a browser to complete tasks on behalf of a user.
- The robots.txt token for Manus-User is Manus-User.
- Blocking an AI agent has no effect on search rankings.
- Manus-User robots.txt support: Not documented.
- Recommendation for Generative Engine Optimization (GEO): Your choice.
What is Manus-User?
Manus navigates, reads and acts on websites to finish multi-step tasks for its users.
Its robots.txt behaviour is not documented.
Should you block Manus-User?
Blocking Manus-User is a business decision: it protects your content but can lower how well AI products know your brand.
| Effect on search rankings | Blocking an AI agent has no effect on search rankings. |
|---|---|
| Effect on AI visibility | Blocking stops agents from completing tasks on your website for their users, which can cost bookings or sales that agents would have made. |
| Follows robots.txt | Not documented |
| Recommendation | Your choice |
How to block or allow Manus-User
Put the robots.txt rule in the file at the root of every domain and subdomain, for example https://example.com/robots.txt. The token Manus-User is matched case-insensitively. robots.txt alone may not stop Manus-User, so add the Nginx, Apache or Cloudflare rule as well.
robots.txt: block
# Block Manus-User
User-agent: Manus-User
Disallow: /robots.txt: allow
# Allow Manus-User
User-agent: Manus-User
Allow: /robots.txt: partial
# Keep Manus-User out of private areas only
User-agent: Manus-User
Disallow: /wp-admin/
Disallow: /cart/
Disallow: /checkout/
Disallow: /my-account/
Allow: /Nginx
# Nginx: return 403 to Manus-User
if ($http_user_agent ~* "(Manus\-User)") {
return 403;
}Apache
# Apache .htaccess: return 403 to Manus-User
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} (Manus\-User) [NC]
RewriteRule .* - [F,L]Cloudflare WAF
# Cloudflare > Security > WAF > Custom rule, action: Block
(http.user_agent contains "Manus-User")How to verify real Manus-User traffic
Butterfly Effect publishes no IP list or reverse DNS pattern for Manus-User, so the user agent cannot be verified. Anyone can send the same string. Rate-limit unusual volume instead of trusting the name.
How to find Manus-User in your server logs
Search the web server access log for the token. The command below counts Manus-User requests per URL on Nginx or Apache.
grep -i "Manus-User" access.log | awk '{print $7}' | sort | uniq -c | sort -rn | head -20For a full report per AI bot, upload the log to the AI Log File Analyzer, a free tool by Justin Hà.
Manus-User FAQ
Manus-User uses the robots.txt token "Manus-User". Butterfly Effect does not publish a full user-agent string, so match the token inside the User-Agent header.
Butterfly Effect has not documented how Manus-User treats robots.txt. Add a robots.txt rule and back it with a server rule if the traffic matters to you.
Blocking an AI agent has no effect on search rankings. Blocking stops agents from completing tasks on your website for their users, which can cost bookings or sales that agents would have made.
Add two lines to the robots.txt file at the root of each domain and subdomain: "User-agent: Manus-User" followed by "Disallow: /". The token is case-insensitive. Changes can take up to 24 hours to be picked up.
Not reliably. Butterfly Effect publishes no IP list or reverse DNS pattern for Manus-User, so anyone can send the same user agent. Rate-limit unusual volume instead of trusting the name.
Search your server access log for "Manus-User", for example with: grep -i "Manus-User" access.log. The AI Log File Analyzer by Justin Hà counts visits per AI bot from an uploaded log file.
Sources: Public bot registry. Last reviewed by Justin Hà.
See which of these bots actually reach your website
The AI Log File Analyzer by Justin Hà counts visits from GPTBot, ClaudeBot, PerplexityBot and other AI crawlers in your server log, for free. The GEO Technical Package sets up robots.txt, llms.txt and crawler access for AI search.
