diff --git a/Gemfile b/Gemfile
index e876375c..fab74ec3 100644
--- a/Gemfile
+++ b/Gemfile
@@ -11,6 +11,7 @@ gem 'yard-sinatra',   github: 'rkh/yard-sinatra'
 group :test do
   gem 'rspec',        '~> 2.11'
   gem 'factory_girl', '~> 2.4.0'
+  gem 'mocha',        '~> 0.12'
 end
 
 group :development do
diff --git a/Gemfile.lock b/Gemfile.lock
index b1fee1a4..9dafe817 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -20,7 +20,7 @@ GIT
 
 GIT
   remote: git://github.com/travis-ci/travis-core.git
-  revision: 0382e80787319cc496400a2e7cb85feb63e278ec
+  revision: b2f6905573a3b947bc6d3df6802bb03f5dc13bae
   specs:
     travis-core (0.0.1)
       actionmailer (~> 3.2.3)
@@ -129,11 +129,14 @@ GEM
       i18n (>= 0.4.0)
       mime-types (~> 1.16)
       treetop (~> 1.4.8)
+    metaclass (0.0.1)
     metriks (0.9.9.1)
       atomic (~> 1.0)
       avl_tree (~> 1.1.2)
       hitimes (~> 1.1)
     mime-types (1.19)
+    mocha (0.12.3)
+      metaclass (~> 0.0.1)
     multi_json (1.3.6)
     multipart-post (1.1.5)
     net-http-persistent (2.7)
@@ -227,6 +230,7 @@ DEPENDENCIES
   foreman
   hubble!
   micro_migrations!
+  mocha (~> 0.12)
   rake (~> 0.9.2)
   rerun
   rspec (~> 2.11)
diff --git a/lib/travis/api/app.rb b/lib/travis/api/app.rb
index f6820062..b89a1686 100644
--- a/lib/travis/api/app.rb
+++ b/lib/travis/api/app.rb
@@ -7,6 +7,7 @@ require 'backports'
 require 'rack'
 require 'rack/protection'
 require 'active_record'
+require 'redis'
 
 # Rack class implementing the HTTP API.
 # Instances respond to #call.
@@ -15,7 +16,7 @@ require 'active_record'
 #
 # Requires TLS in production.
 class Travis::Api::App
-  autoload :AccessToken,  'travis/api/api/access_token'
+  autoload :AccessToken,  'travis/api/app/access_token'
   autoload :Responder,    'travis/api/app/responder'
   autoload :Endpoint,     'travis/api/app/endpoint'
   autoload :Extensions,   'travis/api/app/extensions'
@@ -57,7 +58,7 @@ class Travis::Api::App
       Middleware.subclasses.each { |m| use(m) }
       endpoints = Endpoint.subclasses
       endpoints -= [Endpoint::Home] if options[:disable_root_endpoint]
-      endpoints.each { |e| map(e.prefix) { run(e) } }
+      endpoints.each { |e| map(e.prefix) { run(e.new) } }
     end
   end
 
diff --git a/lib/travis/api/app/access_token.rb b/lib/travis/api/app/access_token.rb
index c69caaeb..f4944cf9 100644
--- a/lib/travis/api/app/access_token.rb
+++ b/lib/travis/api/app/access_token.rb
@@ -1,9 +1,9 @@
 require 'travis/api/app'
 require 'securerandom'
-require 'redis'
 
 class Travis::Api::App
   class AccessToken
+    DEFAULT_SCOPES = [:public, :private]
     attr_reader :token, :scopes, :user_id
 
     def self.create(options = {})
@@ -16,21 +16,30 @@ class Travis::Api::App
     end
 
     def initialize(options = {})
-      raise ArgumentError, 'must supply either user_id or user' unless options[:user] ^ options[:user_id]
+      raise ArgumentError, 'must supply either user_id or user' unless options.key?(:user) ^ options.key?(:user_id)
+
       @token    = options[:token] || SecureRandom.urlsafe_base64(64)
-      @scopes   = Array(options[:scopes] || options[:scope])
+      @scopes   = Array(options[:scopes] || options[:scope] || DEFAULT_SCOPES).map(&:to_sym)
       @user     = options[:user]
-      @user_id  = options[:user_id] || @user.id
+      @user_id  = Integer(options[:user_id] || @user.id)
     end
 
     def save
       key = key(token)
       redis.del(key)
-      redis.rpush(key, [user_id, nil, *scopes].map(&))
+      redis.rpush(key, [user_id, '', *scopes].map(&:to_s))
     end
 
     def user
-      @user ||= User.find(user_id)
+      @user ||= User.find(user_id) if user_id
+    end
+
+    def user?
+      !!user
+    end
+
+    def to_s
+      token
     end
 
     module Helpers
diff --git a/lib/travis/api/app/endpoint.rb b/lib/travis/api/app/endpoint.rb
index 7ab1f090..44011042 100644
--- a/lib/travis/api/app/endpoint.rb
+++ b/lib/travis/api/app/endpoint.rb
@@ -4,13 +4,10 @@ class Travis::Api::App
   # Superclass for HTTP endpoints. Takes care of prefixing.
   class Endpoint < Responder
     set(:prefix) { "/" << name[/[^:]+$/].underscore }
-    before { content_type :json }
+    register :scoping
 
+    before { content_type :json }
     error(ActiveRecord::RecordNotFound, Sinatra::NotFound) { not_found }
     not_found { content_type =~ /json/ ? { 'file' => 'not found' } : 'file not found' }
-
-    # TODO: Dummy method.
-    def self.scope(name)
-    end
   end
 end
diff --git a/lib/travis/api/app/endpoint/authorization.rb b/lib/travis/api/app/endpoint/authorization.rb
index a6b9cdd9..6d90e9be 100644
--- a/lib/travis/api/app/endpoint/authorization.rb
+++ b/lib/travis/api/app/endpoint/authorization.rb
@@ -31,7 +31,7 @@ class Travis::Api::App
     # This is the recommended way for the official client. We might improve the
     # authorization flow to support third-party clients in the future, too.
     class Authorization < Endpoint
-      set prefix: '/auth', default_scope: :private
+      set prefix: '/auth'
 
       # Parameters:
       #
diff --git a/lib/travis/api/app/endpoint/endpoints.rb b/lib/travis/api/app/endpoint/endpoints.rb
index 588c31fc..5416df99 100644
--- a/lib/travis/api/app/endpoint/endpoints.rb
+++ b/lib/travis/api/app/endpoint/endpoints.rb
@@ -19,7 +19,7 @@ class Travis::Api::App
             'uri'    => (controller.prefix + route.http_path[1..-2]).gsub('//', '/'),
             'verb'   => route.http_verb,
             'doc'    => route.docstring,
-            'scope'  => /scope\W+(\w+)/.match(route.source).try(:[], 1)
+            'scope'  => /scope\W+(\w+)/.match(route.source).try(:[], 1) || controller.default_scope.to_s
           }
           endpoint   = endpoints[controller.prefix] ||= {
             'name'   => namespace.name,
diff --git a/lib/travis/api/app/extensions/scoping.rb b/lib/travis/api/app/extensions/scoping.rb
new file mode 100644
index 00000000..255ab079
--- /dev/null
+++ b/lib/travis/api/app/extensions/scoping.rb
@@ -0,0 +1,44 @@
+require 'travis/api/app'
+
+class Travis::Api::App
+  module Extensions
+    module Scoping
+      module Helpers
+        def access_token
+          env['travis.access_token']
+        end
+
+        def user
+          access_token.user if logged_in?
+        end
+
+        def logged_in?
+          !!access_token
+        end
+
+        def scopes
+          logged_in? ? access_token.scopes : settings.anonymous_scopes
+        end
+      end
+
+      def self.registered(app)
+        app.set default_scope: :public, anonymous_scopes: [:public]
+        app.helpers(Helpers)
+      end
+
+      def scope(name)
+        condition do
+          name = settings.default_scope if name == :default
+          headers['X-OAuth-Scopes'] = scopes.map(&:to_s).join(',')
+          headers['X-Accepted-OAuth-Scopes'] = name.to_s
+          scopes.include? name
+        end
+      end
+
+      def route(verb, path, options = {}, &block)
+        options[:scope] ||= :default
+        super(verb, path, options, &block)
+      end
+    end
+  end
+end
diff --git a/lib/travis/api/app/middleware/access_token.rb b/lib/travis/api/app/middleware/access_token.rb
deleted file mode 100644
index 30db73bd..00000000
--- a/lib/travis/api/app/middleware/access_token.rb
+++ /dev/null
@@ -1,9 +0,0 @@
-require 'travis/api/app'
-
-class Travis::Api::App
-  class Middleware
-    # Checks access tokens and sets appropriate scopes.
-    class AccessToken < Middleware
-    end
-  end
-end
diff --git a/lib/travis/api/app/middleware/scope_check.rb b/lib/travis/api/app/middleware/scope_check.rb
new file mode 100644
index 00000000..94b2f13a
--- /dev/null
+++ b/lib/travis/api/app/middleware/scope_check.rb
@@ -0,0 +1,42 @@
+require 'travis/api/app'
+
+class Travis::Api::App
+  class Middleware
+    # Checks access tokens and sets appropriate scopes.
+    class ScopeCheck < Middleware
+      before do
+        next unless token
+        access_token = AccessToken.find_by_token(token)
+        halt 403, 'access denied' unless access_token
+        env['travis.access_token'] = access_token
+      end
+
+      after do
+        headers['X-OAuth-Scopes'] ||= begin
+          scopes = Array(env['travis.access_token'].try(:scopes))
+          scopes.map(&:to_s).join(',')
+        end
+      end
+
+      def token
+        @token ||= header_token || query_token
+      end
+
+      private
+
+        def query_token
+          params[:access_token] if params[:access_token] and not params[:access_token].empty?
+        end
+
+        def header_token
+          type, payload = env['HTTP_AUTHORIZATION'].to_s.split(" ", 2)
+          return if payload.nil? or payload.empty?
+
+          case type.downcase
+          when 'basic' then payload.unpack("m").first.split(':', 2).first
+          when 'token' then payload.gsub(/^"(.+)"$/, '\1')
+          end
+        end
+    end
+  end
+end
diff --git a/spec/endpoint/authorization_spec.rb b/spec/endpoint/authorization_spec.rb
new file mode 100644
index 00000000..79bdc1b7
--- /dev/null
+++ b/spec/endpoint/authorization_spec.rb
@@ -0,0 +1,62 @@
+require 'spec_helper'
+
+describe Travis::Api::App::Endpoint::Authorization do
+  include Travis::Testing::Stubs
+
+  before do
+    add_endpoint '/info' do
+      get '/login', scope: :private do
+        env['travis.access_token'].user.login
+      end
+    end
+
+    User.stubs(:find_by_login).with(user.login).returns(user)
+    User.stubs(:find).with(user.id).returns(user)
+  end
+
+  describe 'GET /auth/authorize' do
+    pending "not yet implemented"
+  end
+
+  describe 'POST /auth/access_token' do
+    pending "not yet implemented"
+  end
+
+  describe 'POST /auth/github' do
+    before do
+      GH.stubs(:with).with(token: 'private repos').returns stub(:[] => user.login, :headers => {'x-oauth-scopes' => 'repo'})
+      GH.stubs(:with).with(token: 'public repos').returns  stub(:[] => user.login, :headers => {'x-oauth-scopes' => 'public_repo'})
+      GH.stubs(:with).with(token: 'no repos').returns      stub(:[] => user.login, :headers => {'x-oauth-scopes' => 'user'})
+      GH.stubs(:with).with(token: 'invalid token').raises(Faraday::Error::ClientError, 'CLIENT ERROR!')
+    end
+
+    def get_token(github_token)
+      post('/auth/github', token: github_token).should be_ok
+      parsed_body['access_token']
+    end
+
+    def user_for(github_token)
+      get '/info/login', access_token: get_token(github_token)
+      last_response.status.should == 200
+      User.find_by_login(body)
+    end
+
+    it 'accepts tokens with repo scope' do
+      user_for('private repos').should == user
+    end
+
+    it 'accepts tokens with public_repo scope' do
+      user_for('public repos').should == user
+    end
+
+    it 'rejects tokens with user scope' do
+      post('/auth/github', token: 'no repos').should_not be_ok
+      body.should_not include('access_token')
+    end
+
+    it 'rejects tokens with user scope' do
+      post('/auth/github', token: 'invalid token').should_not be_ok
+      body.should_not include('access_token')
+    end
+  end
+end
diff --git a/spec/extensions/scoping_spec.rb b/spec/extensions/scoping_spec.rb
new file mode 100644
index 00000000..5b037f58
--- /dev/null
+++ b/spec/extensions/scoping_spec.rb
@@ -0,0 +1,65 @@
+require 'spec_helper'
+
+describe Travis::Api::App::Extensions::Scoping do
+  include Travis::Testing::Stubs
+
+  before do
+    mock_app do
+      register Travis::Api::App::Extensions::Scoping
+      get('/') { 'ok' }
+      get('/private', scope: :private) { 'ok' }
+    end
+
+    User.stubs(:find).with(user.id).returns(user)
+  end
+
+  def with_scopes(url, *scopes)
+    token = Travis::Api::App::AccessToken.create(user: user, scopes: scopes)
+    get(url, {}, 'travis.access_token' => token)
+  end
+
+  it 'uses the default scope if no token is given' do
+    get('/').should be_ok
+    headers['X-Accepted-OAuth-Scopes'].should == 'public'
+    headers['X-OAuth-Scopes'].should == 'public'
+  end
+
+  it 'allows overriding scopes for anonymous users' do
+    settings.set anonymous_scopes: [:foo]
+    get('/').should_not be_ok
+    headers['X-Accepted-OAuth-Scopes'].should == 'public'
+    headers['X-OAuth-Scopes'].should == 'foo'
+  end
+
+  it 'allows overriding default scope' do
+    settings.set default_scope: :foo
+    get('/').should_not be_ok
+    headers['X-Accepted-OAuth-Scopes'].should == 'foo'
+    headers['X-OAuth-Scopes'].should == 'public'
+  end
+
+  it 'allows overriding default scope and anonymous scope' do
+    settings.set default_scope: :foo, anonymous_scopes: [:foo, :bar]
+    get('/').should be_ok
+    headers['X-Accepted-OAuth-Scopes'].should == 'foo'
+    headers['X-OAuth-Scopes'].should == 'foo,bar'
+  end
+
+  it 'takes the scope from the access token' do
+    with_scopes('/', :foo).should_not be_ok
+    headers['X-Accepted-OAuth-Scopes'].should == 'public'
+    headers['X-OAuth-Scopes'].should == 'foo'
+  end
+
+  it 'accepts the scope from the condition' do
+    with_scopes('/private', :foo, :bar, :private).should be_ok
+    headers['X-Accepted-OAuth-Scopes'].should == 'private'
+    headers['X-OAuth-Scopes'].should == 'foo,bar,private'
+  end
+
+  it 'rejects if scope from condition is missing' do
+    with_scopes('/private', :foo, :bar).should_not be_ok
+    headers['X-Accepted-OAuth-Scopes'].should == 'private'
+    headers['X-OAuth-Scopes'].should == 'foo,bar'
+  end
+end
diff --git a/spec/middleware/access_token_spec.rb b/spec/middleware/access_token_spec.rb
deleted file mode 100644
index 355e37b6..00000000
--- a/spec/middleware/access_token_spec.rb
+++ /dev/null
@@ -1,16 +0,0 @@
-require 'spec_helper'
-
-describe Travis::Api::App::Middleware::AccessToken do
-  before do
-    mock_app do
-      use Travis::Api::App::Middleware::AccessToken
-      get('/check_cors') { 'ok' }
-    end
-  end
-
-  it 'sets associated scope properly'
-  it 'lets through requests without a token'
-  it 'reject requests with an invalide token'
-  it 'rejects expired tokens'
-  it 'checks that the token corresponds to Origin'
-end
\ No newline at end of file
diff --git a/spec/middleware/scope_check_spec.rb b/spec/middleware/scope_check_spec.rb
new file mode 100644
index 00000000..3e6649aa
--- /dev/null
+++ b/spec/middleware/scope_check_spec.rb
@@ -0,0 +1,63 @@
+require 'spec_helper'
+
+describe Travis::Api::App::Middleware::ScopeCheck do
+  include Travis::Testing::Stubs
+
+  let :access_token do
+    Travis::Api::App::AccessToken.create(user: user, scope: :foo)
+  end
+
+  before do
+    mock_app do
+      use Travis::Api::App::Middleware::ScopeCheck
+      get('/') { 'ok' }
+      get('/token') { env['travis.access_token'].to_s }
+    end
+
+    User.stubs(:find).with(user.id).returns(user)
+  end
+
+  it 'lets through requests without a token' do
+    get('/').should be_ok
+    body.should == 'ok'
+    headers['X-OAuth-Scopes'].should_not == 'foo'
+  end
+
+  describe 'sets associated scope properly' do
+    it 'accepts Authorization token header' do
+      get('/', {}, 'HTTP_AUTHORIZATION' => "token #{access_token}").should be_ok
+      headers['X-OAuth-Scopes'].should == 'foo'
+    end
+
+    it 'accepts basic auth' do
+      authorize access_token.to_s, 'x'
+      get('/').should be_ok
+      headers['X-OAuth-Scopes'].should == 'foo'
+    end
+
+    it 'accepts query parameters' do
+      get('/', access_token: access_token.to_s).should be_ok
+      headers['X-OAuth-Scopes'].should == 'foo'
+    end
+  end
+
+  describe 'reject requests with an invalide token' do
+    it 'rejects Authorization token header' do
+      get('/', {}, 'HTTP_AUTHORIZATION' => "token foo").should_not be_ok
+    end
+
+    it 'rejects basic auth' do
+      authorize 'foo', 'x'
+      get('/').should_not be_ok
+    end
+
+    it 'rejects query parameters' do
+      get('/', access_token: 'foo').should_not be_ok
+    end
+  end
+
+  it 'sets env["travis.access_token"]' do
+    authorize access_token.to_s, 'x'
+    get('/token').body.should == access_token.to_s
+  end
+end
\ No newline at end of file
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index accd27bb..bc8a121e 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -4,14 +4,46 @@ require 'rspec'
 require 'travis/api/app'
 require 'sinatra/test_helpers'
 require 'logger'
+require 'gh'
+require 'multi_json'
 
 Travis.logger = Logger.new(StringIO.new)
 Travis::Api::App.setup
 
 Backports.require_relative_dir 'support'
 
-RSpec.configure do |config|
-  config.expect_with :rspec, :stdlib
-  config.include Sinatra::TestHelpers
-  config.before(:each) { set_app Travis::Api::App.new }
+module TestHelpers
+  include Sinatra::TestHelpers
+
+  def custom_endpoints
+    @custom_endpoints ||= []
+  end
+
+  def add_endpoint(prefix, &block)
+    endpoint = Sinatra.new(Travis::Api::App::Endpoint, &block)
+    endpoint.set(prefix: prefix)
+    set_app Travis::Api::App.new
+    custom_endpoints << endpoint
+  end
+
+  def parsed_body
+    MultiJson.decode(body)
+  end
+end
+
+RSpec.configure do |config|
+  config.mock_framework = :mocha
+  config.expect_with :rspec, :stdlib
+  config.include TestHelpers
+
+  config.before :each do
+    ::Redis.connect(url: Travis.config.redis.url).flushdb
+    set_app Travis::Api::App.new
+  end
+
+  config.after :each do
+    custom_endpoints.each do |endpoint|
+      endpoint.superclass.direct_subclasses.delete(endpoint)
+    end
+  end
 end
diff --git a/travis-api.gemspec b/travis-api.gemspec
index 76792ae9..aa4cf14c 100644
--- a/travis-api.gemspec
+++ b/travis-api.gemspec
@@ -25,6 +25,7 @@ Gem::Specification.new do |s|
     "README.md",
     "Rakefile",
     "config.ru",
+    "config/database.yml",
     "lib/travis/api/app.rb",
     "lib/travis/api/app/access_token.rb",
     "lib/travis/api/app/endpoint.rb",
@@ -33,6 +34,36 @@ Gem::Specification.new do |s|
     "lib/travis/api/app/endpoint/branches.rb",
     "lib/travis/api/app/endpoint/builds.rb",
     "lib/travis/api/app/endpoint/documentation.rb",
+    "lib/travis/api/app/endpoint/documentation/css/bootstrap-responsive.css",
+    "lib/travis/api/app/endpoint/documentation/css/bootstrap-responsive.min.css",
+    "lib/travis/api/app/endpoint/documentation/css/bootstrap.css",
+    "lib/travis/api/app/endpoint/documentation/css/bootstrap.min.css",
+    "lib/travis/api/app/endpoint/documentation/css/prettify.css",
+    "lib/travis/api/app/endpoint/documentation/img/glyphicons-halflings-white.png",
+    "lib/travis/api/app/endpoint/documentation/img/glyphicons-halflings.png",
+    "lib/travis/api/app/endpoint/documentation/img/grid-18px-masked.png",
+    "lib/travis/api/app/endpoint/documentation/js/bootstrap.js",
+    "lib/travis/api/app/endpoint/documentation/js/bootstrap.min.js",
+    "lib/travis/api/app/endpoint/documentation/js/jquery.js",
+    "lib/travis/api/app/endpoint/documentation/js/lang-apollo.js",
+    "lib/travis/api/app/endpoint/documentation/js/lang-clj.js",
+    "lib/travis/api/app/endpoint/documentation/js/lang-css.js",
+    "lib/travis/api/app/endpoint/documentation/js/lang-go.js",
+    "lib/travis/api/app/endpoint/documentation/js/lang-hs.js",
+    "lib/travis/api/app/endpoint/documentation/js/lang-lisp.js",
+    "lib/travis/api/app/endpoint/documentation/js/lang-lua.js",
+    "lib/travis/api/app/endpoint/documentation/js/lang-ml.js",
+    "lib/travis/api/app/endpoint/documentation/js/lang-n.js",
+    "lib/travis/api/app/endpoint/documentation/js/lang-proto.js",
+    "lib/travis/api/app/endpoint/documentation/js/lang-scala.js",
+    "lib/travis/api/app/endpoint/documentation/js/lang-sql.js",
+    "lib/travis/api/app/endpoint/documentation/js/lang-tex.js",
+    "lib/travis/api/app/endpoint/documentation/js/lang-vb.js",
+    "lib/travis/api/app/endpoint/documentation/js/lang-vhdl.js",
+    "lib/travis/api/app/endpoint/documentation/js/lang-wiki.js",
+    "lib/travis/api/app/endpoint/documentation/js/lang-xq.js",
+    "lib/travis/api/app/endpoint/documentation/js/lang-yaml.js",
+    "lib/travis/api/app/endpoint/documentation/js/prettify.js",
     "lib/travis/api/app/endpoint/endpoints.rb",
     "lib/travis/api/app/endpoint/home.rb",
     "lib/travis/api/app/endpoint/hooks.rb",