Now kaminari supports grape gem.

.gitignore

@@ -1,5 +1,6 @@
 *.gem
 .bundle
+.idea
 Gemfile.lock
 pkg/*
 

lib/kaminari.rb

@@ -31,6 +31,9 @@ def self.show_warning
 when Sinatra/Padrino:
     gem 'kaminari', :require => 'kaminari/sinatra'
 
+when Grape:
+    gem 'kaminari', :require => 'kaminari/grape'
+
     EOC
   end
 
@@ -51,6 +54,8 @@ def self.hook!
       require 'kaminari/engine'
     elsif sinatra?
       require 'kaminari/sinatra'
+    elsif grape?
+      require 'kaminari/grape'
     else
       Kaminari::Hooks.init!
     end
@@ -68,6 +73,10 @@ def self.rails?
   def self.sinatra?
     defined?(::Sinatra)
   end
+
+  def self.grape?
+    defined?(::Grape)
+  end
 end
 
 Kaminari.load!

lib/kaminari/grape.rb

@@ -0,0 +1,10 @@
+begin
+  require 'grape'
+rescue LoadError
+  raise LoadError, "couldn't load `grape`, check out if appropriately bundled grape gem?"
+end
+
+require 'kaminari'
+
+Kaminari::Hooks.init!
+