Legitbot

Ruby gem to make sure that an IP really belongs to a bot, typically a search engine.

Usage

Suppose you have a Web request and you would like to check it is not diguised:

bot = Legitbot.bot(userAgent, ip)

bot will be nil if no bot signature was found in the User-Agent. Otherwise, it will be an object with methods

bot.detected_as # => :google
bot.valid? # => true
bot.fake? # => false

Sometimes you already know which search engine to expect. For example, you might be using rack-attack:

Rack::Attack.blocklist("fake Googlebot") do |req|
  req.user_agent =~ %r(Googlebot) && Legitbot::Google.fake?(req.ip)
end

Or if you do not like all those ghoulish crawlers stealing your content, evaluating it and getting ready to invade your site with spammers, then block them all:

Rack::Attack.blocklist 'fake search engines' do |request|
  Legitbot.bot(request.user_agent, request.ip)&.fake?
end

Versioning

Semantic versioning with the following clarifications:

• MINOR version is incremented when support for new bots is added.
• PATCH version is incremented when validation logic for a bot changes (IP list updated, for example).

Supported

• Ahrefs
• Amazonbot
• Amazon AdBot
• Applebot
• Baidu spider
• Bingbot
• BLEXBot (WebMeUp)
• DataForSEO
• DuckDuckGo bot
• Google crawlers
• IAS
• OpenAI GPTBot
• Oracle Data Cloud Crawler
• Marginalia
• Meta / Facebook Web crawlers
• Petal search engine
• Pinterest
• Twitterbot, the list of IPs is in the Troubleshooting page
• Yandex robots

License

Apache 2.0

Other projects

• Play Framework variant in Scala: play-legitbot
• Article When (Fake) Googlebots Attack Your Rails App
• Voight-Kampff is a Ruby gem that detects bots by User-Agent
• crawler_detect is a Ruby gem and Rack middleware to detect crawlers by few different request headers, including User-Agent
• Project Honeypot's http:BL can not only classify IP as a search engine, but also label them as suspicious and reports the number of days since the last activity. My implementation of the protocol in Scala is here.
• CIDRAM is a PHP routing manager with built-in support to validate bots.