diff --git a/CHANGELOG.md b/CHANGELOG.md
index e543d47d..f5d0c05e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,9 @@
 master
 ===
 
+* rename `app.add_to_instance` to `Extension.expose_to_application` for adding extension-local methods to the shared app instance.
+* rename `app.add_to_config_context` to `Extension.expose_to_config` for adding extension-local methods to the sandboxed scope of `config.rb`
+* Add `Extension.expose_to_templates`, which auto binds copies of extension-local methods into a Template context.
 * Remove side-loading of CLI tasks from `tasks/`
 * Add the option of naming `config.rb` as `middleman.rb`.
 * Builder extracted from Thor. `after_build` hook now passes an instance of a Builder instead of the Thor CLI.
diff --git a/middleman-core/lib/middleman-core/application.rb b/middleman-core/lib/middleman-core/application.rb
index 02c2ef20..64b36bed 100644
--- a/middleman-core/lib/middleman-core/application.rb
+++ b/middleman-core/lib/middleman-core/application.rb
@@ -305,14 +305,6 @@ module Middleman
       config_context.execute_configure_callbacks(config[:mode])
     end
 
-    def add_to_instance(name, &func)
-      define_singleton_method(name, &func)
-    end
-
-    def add_to_config_context(name, &func)
-      @config_context.define_singleton_method(name, &func)
-    end
-
     # Whether we're in server mode
     # @return [Boolean] If we're in dev mode
     def server?
diff --git a/middleman-core/lib/middleman-core/core_extensions/collections.rb b/middleman-core/lib/middleman-core/core_extensions/collections.rb
index 0a0971b4..f1cea9a5 100644
--- a/middleman-core/lib/middleman-core/core_extensions/collections.rb
+++ b/middleman-core/lib/middleman-core/core_extensions/collections.rb
@@ -18,6 +18,20 @@ module Middleman
 
         attr_accessor :sitemap_collector, :data_collector, :leaves
 
+        # Expose `resources`, `data`, and `collection` to config.
+        expose_to_config resources: :sitemap_collector,
+                         data: :data_collector,
+                         collection: :register_collector
+
+        # Exposes `collection` to templates
+        expose_to_template collection: :collector_value
+
+        helpers do
+          def pagination
+            current_resource.data.pagination
+          end
+        end
+
         def initialize(app, options_hash={}, &block)
           super
 
@@ -29,13 +43,8 @@ module Middleman
           @data_collector = LazyCollectorRoot.new(self)
         end
 
-        Contract Any
         def before_configuration
           @leaves.clear
-
-          app.add_to_config_context :resources, &method(:sitemap_collector)
-          app.add_to_config_context :data, &method(:data_collector)
-          app.add_to_config_context :collection, &method(:register_collector)
         end
 
         Contract Symbol, LazyCollectorStep => Any
@@ -69,16 +78,6 @@ module Middleman
           # Inject descriptors
           resources + ctx.descriptors.map { |d| d.to_resource(app) }
         end
-
-        helpers do
-          def collection(label)
-            extensions[:collections].collector_value(label)
-          end
-
-          def pagination
-            current_resource.data.pagination
-          end
-        end
       end
     end
   end
diff --git a/middleman-core/lib/middleman-core/core_extensions/data.rb b/middleman-core/lib/middleman-core/core_extensions/data.rb
index bc578bff..db2c985e 100644
--- a/middleman-core/lib/middleman-core/core_extensions/data.rb
+++ b/middleman-core/lib/middleman-core/core_extensions/data.rb
@@ -9,6 +9,12 @@ module Middleman
     class Data < Extension
       attr_reader :data_store
 
+      # Make the internal `data_store` method available as `app.data`
+      expose_to_application data: :data_store
+    
+      # Exposes `data` to templates
+      expose_to_template data: :data_store
+
       # The regex which tells Middleman which files are for data
       DATA_FILE_MATCHER = /^(.*?)[\w-]+\.(yml|yaml|json)$/
 
@@ -18,8 +24,6 @@ module Middleman
         @data_store = DataStore.new(app, DATA_FILE_MATCHER)
         app.config.define_setting :data_dir, 'data', 'The directory data files are stored in'
 
-        app.add_to_instance(:data, &method(:data_store))
-
         start_watching(app.config[:data_dir])
       end
 
@@ -42,12 +46,6 @@ module Middleman
         @watcher.update_path(app.config[:data_dir])
       end
 
-      helpers do
-        def data
-          extensions[:data].data_store
-        end
-      end
-
       # The core logic behind the data extension.
       class DataStore
         include Contracts
diff --git a/middleman-core/lib/middleman-core/core_extensions/file_watcher.rb b/middleman-core/lib/middleman-core/core_extensions/file_watcher.rb
index 75d1071c..6a800098 100644
--- a/middleman-core/lib/middleman-core/core_extensions/file_watcher.rb
+++ b/middleman-core/lib/middleman-core/core_extensions/file_watcher.rb
@@ -9,6 +9,12 @@ module Middleman
       Contract IsA['Middleman::Sources']
       attr_reader :sources
 
+      # Make the internal `sources` method available as `app.files`
+      expose_to_application files: :sources
+
+      # Make the internal `sources` method available in config as `files`
+      expose_to_config files: :sources
+
       # The default list of ignores.
       IGNORES = {
         emacs_files: /(^|\/)\.?#/,
@@ -34,10 +40,6 @@ module Middleman
 
         # Watch current source.
         start_watching(app.config[:source])
-
-        # Expose API to app and config.
-        app.add_to_instance(:files, &method(:sources))
-        app.add_to_config_context(:files, &method(:sources))
       end
 
       # Before we config, find initial files.
diff --git a/middleman-core/lib/middleman-core/core_extensions/i18n.rb b/middleman-core/lib/middleman-core/core_extensions/i18n.rb
index bb769faf..c9d74572 100644
--- a/middleman-core/lib/middleman-core/core_extensions/i18n.rb
+++ b/middleman-core/lib/middleman-core/core_extensions/i18n.rb
@@ -7,6 +7,9 @@ class Middleman::CoreExtensions::Internationalization < ::Middleman::Extension
   option :mount_at_root, nil, 'Mount a specific language at the root of the site'
   option :data, 'locales', 'The directory holding your locale configurations'
 
+  # Exposes `langs` to templates
+  expose_to_template :langs
+
   def after_configuration
     # See https://github.com/svenfuchs/i18n/wiki/Fallbacks
     unless options[:no_fallbacks]
@@ -41,12 +44,6 @@ class Middleman::CoreExtensions::Internationalization < ::Middleman::Extension
       ::I18n.t(*args)
     end
 
-    # Access the list of languages supported by this Middleman application
-    # @return [Array<Symbol>]
-    def langs
-      extensions[:i18n].langs
-    end
-
     def locate_partial(partial_name, try_static=false)
       locals_dir = extensions[:i18n].options[:templates_dir]
 
diff --git a/middleman-core/lib/middleman-core/core_extensions/routing.rb b/middleman-core/lib/middleman-core/core_extensions/routing.rb
index 9ffc7fb6..0601d2d0 100644
--- a/middleman-core/lib/middleman-core/core_extensions/routing.rb
+++ b/middleman-core/lib/middleman-core/core_extensions/routing.rb
@@ -6,16 +6,15 @@ module Middleman
       # so it can add metadata to any pages generated by other extensions
       self.resource_list_manipulator_priority = 80
 
+      # Expose the `page` method to config.
+      expose_to_config :page
+
       def initialize(app, options_hash={}, &block)
         super
 
         @page_configs = Set.new
       end
 
-      def before_configuration
-        app.add_to_config_context(:page, &method(:page))
-      end
-
       # @return Array<Middleman::Sitemap::Resource>
       Contract ResourceList => ResourceList
       def manipulate_resource_list(resources)
diff --git a/middleman-core/lib/middleman-core/extension.rb b/middleman-core/lib/middleman-core/extension.rb
index 210ff016..aba6f4c3 100644
--- a/middleman-core/lib/middleman-core/extension.rb
+++ b/middleman-core/lib/middleman-core/extension.rb
@@ -82,6 +82,24 @@ module Middleman
     #   @return [Array<Module>] a list of all the helper modules this extension provides. Set these using {#helpers}.
     class_attribute :defined_helpers, instance_reader: false, instance_writer: false
 
+    # @!attribute exposed_to_application
+    #   @!scope class
+    #   @api private
+    #   @return [Hash<Symbol, Symbol>] a list of all the methods modules this extension exposes to app. Set these using {#expose_to_application}.
+    class_attribute :exposed_to_application, instance_reader: false, instance_writer: false
+
+    # @!attribute exposed_to_config
+    #   @!scope class
+    #   @api private
+    #   @return [Hash<Symbol, Symbol>] a list of all the methods modules this extension exposes to config. Set these using {#expose_to_config}.
+    class_attribute :exposed_to_config, instance_reader: false, instance_writer: false
+
+    # @!attribute exposed_to_template
+    #   @!scope class
+    #   @api private
+    #   @return [Hash<Symbol, Symbol>] a list of all the methods modules this extension exposes to templates. Set these using {#expose_to_template}.
+    class_attribute :exposed_to_template, instance_reader: false, instance_writer: false
+
     # @!attribute ext_name
     #   @!scope class
     #   @return [Symbol] the name this extension is registered under. This is the symbol used to activate the extension.
@@ -138,6 +156,68 @@ module Middleman
         self.defined_helpers += modules
       end
 
+      # Takes a method within this extension and exposes it globally
+      # on the main `app` instance. Used for very low-level extensions
+      # which many other extensions depend upon. Such as Data and
+      # File watching.
+      # @example with Hash:
+      #   expose_to_application global_name: :local_name
+      # @example with Array:
+      #   expose_to_application :method1, :method2
+      # @param [Array<Sumbol>, Hash<Symbol, Symbol>] symbols An optional list of symbols representing instance methods to exposed.
+      # @return [void]
+      def expose_to_application(*symbols)
+        self.exposed_to_application ||= {}
+
+        if symbols.first && symbols.first.is_a?(Hash)
+          self.exposed_to_application.merge!(symbols.first)
+        elsif symbols.is_a? Array
+          symbols.each do |sym|
+            self.exposed_to_application[sym] = sym
+          end
+        end
+      end
+
+      # Takes a method within this extension and exposes it inside the scope
+      # of the config.rb sandbox. 
+      # @example with Hash:
+      #   expose_to_config global_name: :local_name
+      # @example with Array:
+      #   expose_to_config :method1, :method2
+      # @param [Array<Sumbol>, Hash<Symbol, Symbol>] symbols An optional list of symbols representing instance methods to exposed.
+      # @return [void]
+      def expose_to_config(*symbols)
+        self.exposed_to_config ||= {}
+
+        if symbols.first && symbols.first.is_a?(Hash)
+          self.exposed_to_config.merge!(symbols.first)
+        elsif symbols.is_a? Array
+          symbols.each do |sym|
+            self.exposed_to_config[sym] = sym
+          end
+        end
+      end
+
+      # Takes a method within this extension and exposes it inside the scope
+      # of the templating engine. Like `helpers`, but scoped.
+      # @example with Hash:
+      #   expose_to_template global_name: :local_name
+      # @example with Array:
+      #   expose_to_template :method1, :method2
+      # @param [Array<Sumbol>, Hash<Symbol, Symbol>] symbols An optional list of symbols representing instance methods to exposed.
+      # @return [void]
+      def expose_to_template(*symbols)
+        self.exposed_to_template ||= {}
+
+        if symbols.first && symbols.first.is_a?(Hash)
+          self.exposed_to_template.merge!(symbols.first)
+        elsif symbols.is_a? Array
+          symbols.each do |sym|
+            self.exposed_to_template[sym] = sym
+          end
+        end
+      end
+
       # Reset all {Extension.after_extension_activated} callbacks.
       # @api private
       # @return [void]
@@ -191,6 +271,7 @@ module Middleman
       @_helpers = []
       @app = app
 
+      expose_methods
       setup_options(options_hash, &block)
 
       # Bind app hooks to local methods
@@ -227,8 +308,28 @@ module Middleman
     #   @param [Array<Sitemap::Resource>] resources A list of all the resources known to the sitemap.
     #   @return [Array<Sitemap::Resource>] The transformed list of resources.
 
+    def add_exposed_to_context(context)
+      (self.class.exposed_to_template || {}).each do |k, v|
+        context.define_singleton_method(k, &method(v))
+      end
+    end
+
     private
 
+    def expose_methods
+      (self.class.exposed_to_application || {}).each do |k, v|
+        app.define_singleton_method(k, &method(v))
+      end
+
+      (self.class.exposed_to_config || {}).each do |k, v|
+        app.config_context.define_singleton_method(k, &method(v))
+      end
+
+      (self.class.defined_helpers || []).each do |m|
+        app.template_context_class.send(:include, m)
+      end
+    end
+
     # @yield An optional block that can be used to customize options before the extension is activated.
     # @yieldparam Middleman::Configuration::ConfigurationManager] options Extension options
     def setup_options(options_hash)
diff --git a/middleman-core/lib/middleman-core/extension_manager.rb b/middleman-core/lib/middleman-core/extension_manager.rb
index 0356f0bd..2fdef893 100644
--- a/middleman-core/lib/middleman-core/extension_manager.rb
+++ b/middleman-core/lib/middleman-core/extension_manager.rb
@@ -68,13 +68,15 @@ module Middleman
       end
 
       instances.each do |ext|
-        # Forward Extension helpers to TemplateContext
-        Array(ext.class.defined_helpers).each do |m|
-          @app.template_context_class.send(:include, m)
-        end
-
         ::Middleman::Extension.activated_extension(ext)
       end
     end
+
+    def add_exposed_to_context(context)
+      @activated.each do |(_, ext)|
+        ext.add_exposed_to_context(context)
+      end
+    end
+
   end
 end
diff --git a/middleman-core/lib/middleman-core/renderers/haml.rb b/middleman-core/lib/middleman-core/renderers/haml.rb
index cde27a70..1ed893ac 100644
--- a/middleman-core/lib/middleman-core/renderers/haml.rb
+++ b/middleman-core/lib/middleman-core/renderers/haml.rb
@@ -48,6 +48,13 @@ module Middleman
         # Add haml helpers to context
         ::Middleman::TemplateContext.send :include, ::Haml::Helpers
       end
+
+      def add_exposed_to_context(context)
+        super
+        
+        context.init_haml_helpers if context.respond_to?(:init_haml_helpers)
+      end
+
     end
   end
 end
diff --git a/middleman-core/lib/middleman-core/sitemap/extensions/ignores.rb b/middleman-core/lib/middleman-core/sitemap/extensions/ignores.rb
index 41d9d88a..58b89776 100644
--- a/middleman-core/lib/middleman-core/sitemap/extensions/ignores.rb
+++ b/middleman-core/lib/middleman-core/sitemap/extensions/ignores.rb
@@ -3,12 +3,15 @@ module Middleman
     module Extensions
       # Class to handle managing ignores
       class Ignores < Extension
+        # Expose `create_ignore` as `app.ignore`
+        expose_to_application ignore: :create_ignore
+
+        # Expose `create_ignore` to config as `ignore`
+        expose_to_config ignore: :create_ignore
+
         def initialize(app, config={}, &block)
           super
 
-          @app.add_to_config_context(:ignore, &method(:create_ignore))
-          @app.define_singleton_method(:ignore, &method(:create_ignore))
-
           # Array of callbacks which can ass ignored
           @ignored_callbacks = Set.new
 
diff --git a/middleman-core/lib/middleman-core/sitemap/extensions/proxies.rb b/middleman-core/lib/middleman-core/sitemap/extensions/proxies.rb
index da23c9e9..0ad0a512 100644
--- a/middleman-core/lib/middleman-core/sitemap/extensions/proxies.rb
+++ b/middleman-core/lib/middleman-core/sitemap/extensions/proxies.rb
@@ -7,12 +7,15 @@ module Middleman
       # Manages the list of proxy configurations and manipulates the sitemap
       # to include new resources based on those configurations
       class Proxies < Extension
+        # Expose `create_proxy` as `app.proxy`
+        expose_to_application proxy: :create_proxy
+
+        # Expose `create_proxy` to config as `proxy`
+        expose_to_config proxy: :create_proxy
+
         def initialize(app, config={}, &block)
           super
 
-          @app.add_to_config_context(:proxy, &method(:create_proxy))
-          @app.define_singleton_method(:proxy, &method(:create_proxy))
-
           @proxy_configs = Set.new
           @post_config = false
         end
diff --git a/middleman-core/lib/middleman-core/sitemap/extensions/redirects.rb b/middleman-core/lib/middleman-core/sitemap/extensions/redirects.rb
index 418f5d73..c002a0b2 100644
--- a/middleman-core/lib/middleman-core/sitemap/extensions/redirects.rb
+++ b/middleman-core/lib/middleman-core/sitemap/extensions/redirects.rb
@@ -7,11 +7,13 @@ module Middleman
       # Manages the list of proxy configurations and manipulates the sitemap
       # to include new resources based on those configurations
       class Redirects < Extension
+
+        # Expose `create_redirect` to config as `redirect`
+        expose_to_config redirect: :create_redirect
+
         def initialize(app, config={}, &block)
           super
 
-          @app.add_to_config_context(:redirect, &method(:create_redirect))
-
           @redirects = {}
         end
 
diff --git a/middleman-core/lib/middleman-core/sitemap/extensions/request_endpoints.rb b/middleman-core/lib/middleman-core/sitemap/extensions/request_endpoints.rb
index 63de03c7..9b976fdd 100644
--- a/middleman-core/lib/middleman-core/sitemap/extensions/request_endpoints.rb
+++ b/middleman-core/lib/middleman-core/sitemap/extensions/request_endpoints.rb
@@ -4,13 +4,15 @@ module Middleman
   module Sitemap
     module Extensions
       class RequestEndpoints < Extension
+
+        # Expose `create_endpoint` to config as `endpoint`
+        expose_to_config endpoint: :create_endpoint
+
         # Manages the list of proxy configurations and manipulates the sitemap
         # to include new resources based on those configurations
         def initialize(app, config={}, &block)
           super
 
-          @app.add_to_config_context(:endpoint, &method(:create_endpoint))
-
           @endpoints = {}
         end
 
diff --git a/middleman-core/lib/middleman-core/template_renderer.rb b/middleman-core/lib/middleman-core/template_renderer.rb
index 34692b49..c77efcbb 100644
--- a/middleman-core/lib/middleman-core/template_renderer.rb
+++ b/middleman-core/lib/middleman-core/template_renderer.rb
@@ -58,8 +58,8 @@ module Middleman
       # Sandboxed class for template eval
       context = @app.template_context_class.new(@app, locals, options)
 
-      # TODO: Only for HAML files
-      context.init_haml_helpers if context.respond_to?(:init_haml_helpers)
+      # Add extension helpers to context.
+      @app.extensions.add_exposed_to_context(context)
 
       content = _render_with_all_renderers(path, locs, context, opts, &block)