diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3b1fbeb58a..2d0c2f8045 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,10 @@
 * [#691](https://github.com/intridea/grape/issues/691): Added `at_least_one_of` parameter validator - [@dblock](https://github.com/dblock).
 * [#687](https://github.com/intridea/grape/pull/687): Fix: `mutually_exclusive` and `exactly_one_of` validation error messages now label parameters as strings, consistently with `requires` and `optional` - [@dblock](https://github.com/dblock).
 * [#698](https://github.com/intridea/grape/pull/698): `error!` sets `status` for `Endpoint` too - [@dspaeth-faber](https://github.com/dspaeth-faber).
+* [#703](https://github.com/intridea/grape/pull/703): Added support for Auth-Middleware extension - [@dspaeth-faber](https://github.com/dspaeth-faber).
+* [#703](https://github.com/intridea/grape/pull/703): Removed `Grape::Middleware::Auth::Basic` - [@dspaeth-faber](https://github.com/dspaeth-faber).
+* [#703](https://github.com/intridea/grape/pull/703): Removed `Grape::Middleware::Auth::Digest` - [@dspaeth-faber](https://github.com/dspaeth-faber).
+* [#703](https://github.com/intridea/grape/pull/703): Removed `Grape::Middleware::Auth::OAuth2` - [@dspaeth-faber](https://github.com/dspaeth-faber).
 * Your contribution here.
 
 0.8.0 (7/10/2014)
diff --git a/README.md b/README.md
index f5b26aa3b2..a74f725f67 100644
--- a/README.md
+++ b/README.md
@@ -1468,7 +1468,8 @@ formatter.
 
 ### Basic and Digest Auth
 
-Grape has built-in Basic and Digest authentication.
+Grape has built-in Basic and Digest authentication (the given `block` 
+is executed in the context of the current `Endpoint`).
 
 ```ruby
 http_basic do |username, password|
@@ -1484,6 +1485,33 @@ http_digest({ realm: 'Test Api', opaque: 'app secret' }) do |username|
 end
 ```
 
+### Register custom middleware for authentication
+
+Grape can use custom Middleware for authentication. How to implement these
+Middleware have a look at `Rack::Auth::Basic` or similar implementations.
+
+
+For registering a Middlewar you need the following options:
+
+* `label` - the name for your authenticator to use it later
+* `MiddlewareClass` - the MiddlewareClass to use for authentication
+* `option_lookup_proc` - A Proc with one Argument to lookup the options at 
+runtime (return value is an `Array` as Paramter for the Middleware).
+
+Example:
+
+```ruby
+
+Grape::Middleware::Auth::Strategies.add(:my_auth, AuthMiddleware, ->(options) { [options[:realm]] } )
+
+
+auth :my_auth ,{ real: 'Test Api'} do |credentials|
+  # lookup the user's password here
+  { 'user1' => 'password1' }[username]
+end
+
+```
+
 Use [warden-oauth2](https://github.com/opperator/warden-oauth2) or [rack-oauth2](https://github.com/nov/rack-oauth2) for OAuth2 support.
 
 ## Describing and Inspecting an API
diff --git a/lib/grape.rb b/lib/grape.rb
index bb151c9e48..41c1980819 100644
--- a/lib/grape.rb
+++ b/lib/grape.rb
@@ -77,10 +77,10 @@ module Middleware
     autoload :Error,             'grape/middleware/error'
 
     module Auth
-      autoload :OAuth2,         'grape/middleware/auth/oauth2'
-      autoload :Base,	          'grape/middleware/auth/base'
-      autoload :Basic,          'grape/middleware/auth/basic'
-      autoload :Digest,	        'grape/middleware/auth/digest'
+      autoload :Base,            'grape/middleware/auth/base'
+      autoload :DSL,             'grape/middleware/auth/dsl'
+      autoload :StrategyInfo,    'grape/middleware/auth/strategy_info'
+      autoload :Strategies,      'grape/middleware/auth/strategies'
     end
 
     module Versioner
diff --git a/lib/grape/api.rb b/lib/grape/api.rb
index 336c9266f0..0a270eb755 100644
--- a/lib/grape/api.rb
+++ b/lib/grape/api.rb
@@ -4,6 +4,7 @@ module Grape
   # class in order to build an API.
   class API
     extend Validations::ClassMethods
+    extend Grape::Middleware::Auth::DSL
 
     class << self
       attr_reader :endpoints, :instance, :routes, :route_set, :settings, :versions
@@ -301,31 +302,6 @@ def helpers(new_mod = nil, &block)
         end
       end
 
-      # Add an authentication type to the API. Currently
-      # only `:http_basic`, `:http_digest` and `:oauth2` are supported.
-      def auth(type = nil, options = {}, &block)
-        if type
-          set(:auth, { type: type.to_sym, proc: block }.merge(options))
-        else
-          settings[:auth]
-        end
-      end
-
-      # Add HTTP Basic authorization to the API.
-      #
-      # @param [Hash] options A hash of options.
-      # @option options [String] :realm "API Authorization" The HTTP Basic realm.
-      def http_basic(options = {}, &block)
-        options[:realm] ||= "API Authorization"
-        auth :http_basic, options, &block
-      end
-
-      def http_digest(options = {}, &block)
-        options[:realm] ||= "API Authorization"
-        options[:opaque] ||= "secret"
-        auth :http_digest, options, &block
-      end
-
       def mount(mounts)
         mounts = { mounts => '/' } unless mounts.respond_to?(:each_pair)
         mounts.each_pair do |app, path|
diff --git a/lib/grape/endpoint.rb b/lib/grape/endpoint.rb
index 2b1f9fd045..9f4271120c 100644
--- a/lib/grape/endpoint.rb
+++ b/lib/grape/endpoint.rb
@@ -456,22 +456,6 @@ def build_middleware
         end
       end
 
-      if settings[:auth]
-        auth_proc         = settings[:auth][:proc]
-        auth_proc_context = self
-        auth_middleware   = {
-          http_basic:   { class: Rack::Auth::Basic,       args: [settings[:auth][:realm]] },
-          http_digest:  { class: Rack::Auth::Digest::MD5, args: [settings[:auth][:realm], settings[:auth][:opaque]] }
-        }[settings[:auth][:type]]
-
-        # evaluate auth proc in context of endpoint
-        if auth_middleware
-          b.use auth_middleware[:class], *auth_middleware[:args] do |*args|
-            auth_proc_context.instance_exec(*args, &auth_proc)
-          end
-        end
-      end
-
       if settings[:version]
         b.use Grape::Middleware::Versioner.using(settings[:version_options][:using]),
               versions: settings[:version] ? settings[:version].flatten : nil,
diff --git a/lib/grape/middleware/auth/base.rb b/lib/grape/middleware/auth/base.rb
index 4fdc485972..246ce620f4 100644
--- a/lib/grape/middleware/auth/base.rb
+++ b/lib/grape/middleware/auth/base.rb
@@ -3,25 +3,41 @@
 module Grape
   module Middleware
     module Auth
-      class Base < Grape::Middleware::Base
-        attr_reader :authenticator
+      class Base
+        attr_accessor :options, :app, :env
 
-        def initialize(app, options = {}, &authenticator)
-          super(app, options)
-          @authenticator = authenticator
+        def initialize(app, options = {})
+          @app = app
+          @options = options || {}
         end
 
-        def base_request
-          raise NotImplementedError, "You must implement base_request."
+        def context
+          env['api.endpoint']
         end
 
-        def credentials
-          base_request.provided? ? base_request.credentials : [nil, nil]
+        def call(env)
+          dup._call(env)
         end
 
-        def before
-          unless authenticator.call(*credentials)
-            throw :error, status: 401, message: "API Authorization Failed."
+        def _call(env)
+          self.env = env
+
+          if options.key?(:type)
+            auth_proc         = options[:proc]
+            auth_proc_context = context
+
+            strategy_info   = Grape::Middleware::Auth::Strategies[options[:type]]
+
+            throw(:error, status: 401, message: "API Authorization Failed.") unless strategy_info.present?
+
+            strategy = strategy_info.create(@app, options) do |*args|
+              auth_proc_context.instance_exec(*args, &auth_proc)
+            end
+
+            strategy.call(env)
+
+          else
+            app.call(env)
           end
         end
       end
diff --git a/lib/grape/middleware/auth/basic.rb b/lib/grape/middleware/auth/basic.rb
deleted file mode 100644
index 4c815c0332..0000000000
--- a/lib/grape/middleware/auth/basic.rb
+++ /dev/null
@@ -1,13 +0,0 @@
-require 'rack/auth/basic'
-
-module Grape
-  module Middleware
-    module Auth
-      class Basic < Grape::Middleware::Auth::Base
-        def base_request
-          Rack::Auth::Basic::Request.new(env)
-        end
-      end
-    end
-  end
-end
diff --git a/lib/grape/middleware/auth/digest.rb b/lib/grape/middleware/auth/digest.rb
deleted file mode 100644
index 8b2e633861..0000000000
--- a/lib/grape/middleware/auth/digest.rb
+++ /dev/null
@@ -1,13 +0,0 @@
-require 'rack/auth/digest/md5'
-
-module Grape
-  module Middleware
-    module Auth
-      class Digest < Grape::Middleware::Auth::Base
-        def base_request
-          Rack::Auth::Digest::Request.new(env)
-        end
-      end
-    end
-  end
-end
diff --git a/lib/grape/middleware/auth/dsl.rb b/lib/grape/middleware/auth/dsl.rb
new file mode 100644
index 0000000000..06ea4326c6
--- /dev/null
+++ b/lib/grape/middleware/auth/dsl.rb
@@ -0,0 +1,35 @@
+require 'rack/auth/basic'
+
+module Grape
+  module Middleware
+    module Auth
+      module DSL
+        # Add an authentication type to the API. Currently
+        # only `:http_basic`, `:http_digest` are supported.
+        def auth(type = nil, options = {}, &block)
+          if type
+            set(:auth, { type: type.to_sym, proc: block }.merge(options))
+            use Grape::Middleware::Auth::Base, settings[:auth]
+          else
+            settings[:auth]
+          end
+        end
+
+        # Add HTTP Basic authorization to the API.
+        #
+        # @param [Hash] options A hash of options.
+        # @option options [String] :realm "API Authorization" The HTTP Basic realm.
+        def http_basic(options = {}, &block)
+          options[:realm] ||= "API Authorization"
+          auth :http_basic, options, &block
+        end
+
+        def http_digest(options = {}, &block)
+          options[:realm] ||= "API Authorization"
+          options[:opaque] ||= "secret"
+          auth :http_digest, options, &block
+        end
+      end
+    end
+  end
+end
diff --git a/lib/grape/middleware/auth/oauth2.rb b/lib/grape/middleware/auth/oauth2.rb
deleted file mode 100644
index 4120c280bd..0000000000
--- a/lib/grape/middleware/auth/oauth2.rb
+++ /dev/null
@@ -1,83 +0,0 @@
-module Grape
-  module Middleware
-    module Auth
-      # OAuth 2.0 authorization for Grape APIs.
-      class OAuth2 < Grape::Middleware::Base
-        def default_options
-          {
-            token_class: 'AccessToken',
-            realm: 'OAuth API',
-            parameter: %w(bearer_token oauth_token access_token),
-            accepted_headers: %w(HTTP_AUTHORIZATION X_HTTP_AUTHORIZATION X-HTTP_AUTHORIZATION REDIRECT_X_HTTP_AUTHORIZATION),
-            header: [/Bearer (.*)/i, /OAuth (.*)/i],
-            required: true
-          }
-        end
-
-        def before
-          verify_token(token_parameter || token_header)
-        end
-
-        def request
-          @request ||= Grape::Request.new(env)
-        end
-
-        def params
-          @params ||= request.params
-        end
-
-        def token_parameter
-          Array(options[:parameter]).each do |p|
-            return params[p] if params[p]
-          end
-          nil
-        end
-
-        def token_header
-          return false unless authorization_header
-          Array(options[:header]).each do |regexp|
-            return $1 if authorization_header =~ regexp
-          end
-          nil
-        end
-
-        def authorization_header
-          options[:accepted_headers].each do |head|
-            return env[head] if env[head]
-          end
-          nil
-        end
-
-        def token_class
-          @klass ||= eval(options[:token_class]) # rubocop:disable Eval
-        end
-
-        def verify_token(token)
-          token = token_class.verify(token)
-          if token
-            if token.respond_to?(:expired?) && token.expired?
-              error_out(401, 'invalid_grant')
-            else
-              if !token.respond_to?(:permission_for?) || token.permission_for?(env)
-                env['api.token'] = token
-              else
-                error_out(403, 'insufficient_scope')
-              end
-            end
-          elsif !!options[:required]
-            error_out(401, 'invalid_grant')
-          end
-        end
-
-        def error_out(status, error)
-          throw :error,
-                message: error,
-                status: status,
-                headers: {
-                  'WWW-Authenticate' => "OAuth realm='#{options[:realm]}', error='#{error}'"
-                }
-        end
-      end
-    end
-  end
-end
diff --git a/lib/grape/middleware/auth/strategies.rb b/lib/grape/middleware/auth/strategies.rb
new file mode 100644
index 0000000000..8ac3a4889c
--- /dev/null
+++ b/lib/grape/middleware/auth/strategies.rb
@@ -0,0 +1,24 @@
+module Grape
+  module Middleware
+    module Auth
+      module Strategies
+        module_function
+
+        def add(label, strategy, option_fetcher = ->(_) { [] })
+          auth_strategies[label] =  StrategyInfo.new(strategy, option_fetcher)
+        end
+
+        def auth_strategies
+          @auth_strategies ||= {
+            http_basic: StrategyInfo.new(Rack::Auth::Basic, ->(settings) {[settings[:realm]] }),
+            http_digest: StrategyInfo.new(Rack::Auth::Digest::MD5, ->(settings) { [settings[:realm], settings[:opaque]] })
+          }
+        end
+
+        def [](label)
+          auth_strategies[label]
+        end
+      end
+    end
+  end
+end
diff --git a/lib/grape/middleware/auth/strategy_info.rb b/lib/grape/middleware/auth/strategy_info.rb
new file mode 100644
index 0000000000..13ea751ded
--- /dev/null
+++ b/lib/grape/middleware/auth/strategy_info.rb
@@ -0,0 +1,15 @@
+module Grape
+  module Middleware
+    module Auth
+      StrategyInfo = Struct.new(:auth_class, :settings_fetcher) do
+
+        def create(app, options, &block)
+          strategy_args = settings_fetcher.call(options)
+
+          auth_class.new(app, *strategy_args, &block)
+        end
+
+      end
+    end
+  end
+end
diff --git a/spec/grape/middleware/auth/basic_spec.rb b/spec/grape/middleware/auth/basic_spec.rb
deleted file mode 100644
index 0fd0d4cbfb..0000000000
--- a/spec/grape/middleware/auth/basic_spec.rb
+++ /dev/null
@@ -1,31 +0,0 @@
-require 'spec_helper'
-
-require 'base64'
-
-describe Grape::Middleware::Auth::Basic do
-  def app
-    Rack::Builder.new do |b|
-      b.use Grape::Middleware::Error
-      b.use(Grape::Middleware::Auth::Basic) do |u, p|
-        u && p && u == p
-      end
-      b.run lambda { |env| [200, {}, ["Hello there."]] }
-    end
-  end
-
-  it 'throws a 401 if no auth is given' do
-    @proc = lambda { false }
-    get '/whatever'
-    expect(last_response.status).to eq(401)
-  end
-
-  it 'authenticates if given valid creds' do
-    get '/whatever', {}, 'HTTP_AUTHORIZATION' => encode_basic_auth('admin', 'admin')
-    expect(last_response.status).to eq(200)
-  end
-
-  it 'throws a 401 is wrong auth is given' do
-    get '/whatever', {}, 'HTTP_AUTHORIZATION' => encode_basic_auth('admin', 'wrong')
-    expect(last_response.status).to eq(401)
-  end
-end
diff --git a/spec/grape/middleware/auth/digest_spec.rb b/spec/grape/middleware/auth/digest_spec.rb
deleted file mode 100644
index f61593b148..0000000000
--- a/spec/grape/middleware/auth/digest_spec.rb
+++ /dev/null
@@ -1,47 +0,0 @@
-require 'spec_helper'
-
-RSpec::Matchers.define :be_challenge do
-  match do |actual_response|
-    actual_response.status == 401 &&
-    actual_response['WWW-Authenticate'] =~ /^Digest / &&
-    actual_response.body.empty?
-  end
-end
-
-class Test < Grape::API
-  http_digest(realm: 'Test Api', opaque: 'secret') do |username|
-    { 'foo' => 'bar' }[username]
-  end
-
-  get '/test' do
-    [{ hey: 'you' }, { there: 'bar' }, { foo: 'baz' }]
-  end
-end
-
-describe Grape::Middleware::Auth::Digest do
-  def app
-    Test
-  end
-
-  it 'is a digest authentication challenge' do
-    get '/test'
-    expect(last_response).to be_challenge
-  end
-
-  it 'throws a 401 if no auth is given' do
-    get '/test'
-    expect(last_response.status).to eq(401)
-  end
-
-  it 'authenticates if given valid creds' do
-    digest_authorize "foo", "bar"
-    get '/test'
-    expect(last_response.status).to eq(200)
-  end
-
-  it 'throws a 401 if given invalid creds' do
-    digest_authorize "bar", "foo"
-    get '/test'
-    expect(last_response.status).to eq(401)
-  end
-end
diff --git a/spec/grape/middleware/auth/oauth2_spec.rb b/spec/grape/middleware/auth/oauth2_spec.rb
deleted file mode 100644
index 026cb11384..0000000000
--- a/spec/grape/middleware/auth/oauth2_spec.rb
+++ /dev/null
@@ -1,135 +0,0 @@
-require 'spec_helper'
-
-describe Grape::Middleware::Auth::OAuth2 do
-  class FakeToken
-    attr_accessor :token
-
-    def self.verify(token)
-      FakeToken.new(token) if !!token && %w(g e).include?(token[0..0])
-    end
-
-    def initialize(token)
-      @token = token
-    end
-
-    def expired?
-      @token[0..0] == 'e'
-    end
-
-    def permission_for?(env)
-      env['PATH_INFO'] == '/forbidden' ? false : true
-    end
-  end
-
-  def app
-    Rack::Builder.app do
-      use Grape::Middleware::Auth::OAuth2, token_class: 'FakeToken'
-      run lambda { |env| [200, {}, [(env['api.token'].token if env['api.token'])]] }
-    end
-  end
-
-  context 'with the token in the query string' do
-    context 'and a valid token' do
-      before { get '/awesome?access_token=g123' }
-
-      it 'sets env["api.token"]' do
-        expect(last_response.body).to eq('g123')
-      end
-    end
-
-    context 'and an invalid token' do
-      before do
-        @err = catch :error do
-          get '/awesome?access_token=b123'
-        end
-      end
-
-      it 'throws an error' do
-        expect(@err[:status]).to eq(401)
-      end
-
-      it 'sets the WWW-Authenticate header in the response' do
-        expect(@err[:headers]['WWW-Authenticate']).to eq("OAuth realm='OAuth API', error='invalid_grant'")
-      end
-    end
-  end
-
-  context 'with an expired token' do
-    before do
-      @err = catch :error do
-        get '/awesome?access_token=e123'
-      end
-    end
-
-    it 'throws an error' do
-      expect(@err[:status]).to eq(401)
-    end
-
-    it 'sets the WWW-Authenticate header in the response to error' do
-      expect(@err[:headers]['WWW-Authenticate']).to eq("OAuth realm='OAuth API', error='invalid_grant'")
-    end
-  end
-
-  %w(HTTP_AUTHORIZATION X_HTTP_AUTHORIZATION X-HTTP_AUTHORIZATION REDIRECT_X_HTTP_AUTHORIZATION).each do |head|
-    context "with the token in the #{head} header" do
-      before do
-        get '/awesome', {}, head => 'OAuth g123'
-      end
-
-      it 'sets env["api.token"]' do
-        expect(last_response.body).to eq('g123')
-      end
-    end
-  end
-
-  context 'with the token in the POST body' do
-    before do
-      post '/awesome', 'access_token' => 'g123'
-    end
-
-    it 'sets env["api.token"]' do
-      expect(last_response.body).to eq('g123')
-    end
-  end
-
-  context 'when accessing something outside its scope' do
-    before do
-      @err = catch :error do
-        get '/forbidden?access_token=g123'
-      end
-    end
-
-    it 'throws an error' do
-      expect(@err[:status]).to eq(403)
-    end
-
-    it 'sets the WWW-Authenticate header in the response to error' do
-      expect(@err[:headers]['WWW-Authenticate']).to eq("OAuth realm='OAuth API', error='insufficient_scope'")
-    end
-  end
-
-  context 'when authorization is not required' do
-    def app
-      Rack::Builder.app do
-        use Grape::Middleware::Auth::OAuth2, token_class: 'FakeToken', required: false
-        run lambda { |env| [200, {}, [(env['api.token'].token if env['api.token'])]] }
-      end
-    end
-
-    context 'with no token' do
-      before { post '/awesome' }
-
-      it 'succeeds anyway' do
-        expect(last_response.status).to eq(200)
-      end
-    end
-
-    context 'with a valid token' do
-      before { get '/awesome?access_token=g123' }
-
-      it 'sets env["api.token"]' do
-        expect(last_response.body).to eq('g123')
-      end
-    end
-  end
-end
diff --git a/spec/grape/middleware/auth/strategies_spec.rb b/spec/grape/middleware/auth/strategies_spec.rb
new file mode 100644
index 0000000000..13003582ed
--- /dev/null
+++ b/spec/grape/middleware/auth/strategies_spec.rb
@@ -0,0 +1,81 @@
+require 'spec_helper'
+
+require 'base64'
+
+describe Grape::Middleware::Auth::Strategies do
+  context 'Basic Auth' do
+    def app
+      proc = ->(u, p) { u && p && u == p }
+      Rack::Builder.new do |b|
+        b.use Grape::Middleware::Error
+        b.use(Grape::Middleware::Auth::Base, type: :http_basic, proc: proc)
+        b.run lambda { |env| [200, {}, ["Hello there."]] }
+      end
+    end
+
+    it 'throws a 401 if no auth is given' do
+      @proc = lambda { false }
+      get '/whatever'
+      expect(last_response.status).to eq(401)
+    end
+
+    it 'authenticates if given valid creds' do
+      get '/whatever', {}, 'HTTP_AUTHORIZATION' => encode_basic_auth('admin', 'admin')
+      expect(last_response.status).to eq(200)
+    end
+
+    it 'throws a 401 is wrong auth is given' do
+      get '/whatever', {}, 'HTTP_AUTHORIZATION' => encode_basic_auth('admin', 'wrong')
+      expect(last_response.status).to eq(401)
+    end
+  end
+
+  context 'Digest MD5 Auth' do
+    RSpec::Matchers.define :be_challenge do
+      match do |actual_response|
+        actual_response.status == 401 &&
+            actual_response['WWW-Authenticate'] =~ /^Digest / &&
+            actual_response.body.empty?
+      end
+    end
+
+    module StrategiesSpec
+      class Test < Grape::API
+        http_digest(realm: 'Test Api', opaque: 'secret') do |username|
+          { 'foo' => 'bar' }[username]
+        end
+
+        get '/test' do
+          [{ hey: 'you' }, { there: 'bar' }, { foo: 'baz' }]
+        end
+      end
+    end
+
+    def app
+      StrategiesSpec::Test
+    end
+
+    it 'is a digest authentication challenge' do
+      get '/test'
+      expect(last_response).to be_challenge
+    end
+
+    it 'throws a 401 if no auth is given' do
+      get '/test'
+      expect(last_response.status).to eq(401)
+    end
+
+    it 'authenticates if given valid creds' do
+      digest_authorize "foo", "bar"
+      get '/test'
+      expect(last_response.status).to eq(200)
+    end
+
+    it 'throws a 401 if given invalid creds' do
+      digest_authorize "bar", "foo"
+      get '/test'
+      expect(last_response.status).to eq(401)
+    end
+  end
+
+end