diff --git a/spec/context_spec.cr b/spec/context_spec.cr
index ea1dbb6..1bfb9f7 100644
--- a/spec/context_spec.cr
+++ b/spec/context_spec.cr
@@ -64,7 +64,6 @@ describe "Context" do
     io = IO::Memory.new
     response = HTTP::Server::Response.new(io)
     context = HTTP::Server::Context.new(request, response)
-    context.app = app
     app.filter_handler.call(context)
     app.route_handler.call(context)
     context.store["key"].should eq "value"
diff --git a/spec/dsl_helper.cr b/spec/dsl_helper.cr
index 39a4e91..a636c4c 100644
--- a/spec/dsl_helper.cr
+++ b/spec/dsl_helper.cr
@@ -12,11 +12,11 @@ class CustomLogHandler < Kemal::BaseLogHandler
   end
 end
 
-def create_request_and_return_io(handler, request)
+def create_request_and_return_io(handler, request, app = Kemal.application)
   io = IO::Memory.new
   response = HTTP::Server::Response.new(io)
   context = HTTP::Server::Context.new(request, response)
-  context.app = Kemal.application
+  context.app = app
   handler.call(context)
   response.close
   io.rewind
diff --git a/spec/exception_handler_spec.cr b/spec/exception_handler_spec.cr
index 95df288..dc72b94 100644
--- a/spec/exception_handler_spec.cr
+++ b/spec/exception_handler_spec.cr
@@ -26,9 +26,8 @@ describe "Kemal::ExceptionHandler" do
     app.get "/" do |env|
       env.response.status_code = 403
     end
-    context.app = app
     subject = Kemal::ExceptionHandler.new(app)
-    subject.next = Kemal::RouteHandler.new
+    subject.next = app.route_handler
     subject.call(context)
     response.close
     io.rewind
@@ -50,9 +49,8 @@ describe "Kemal::ExceptionHandler" do
     app.get "/" do |env|
       env.response.status_code = 500
     end
-    context.app = app
     subject = Kemal::ExceptionHandler.new(app)
-    subject.next = Kemal::RouteHandler.new
+    subject.next = app.route_handler
     subject.call(context)
     response.close
     io.rewind
@@ -75,9 +73,8 @@ describe "Kemal::ExceptionHandler" do
       env.response.content_type = "application/json"
       env.response.status_code = 500
     end
-    context.app = app
     subject = Kemal::ExceptionHandler.new(app)
-    subject.next = Kemal::RouteHandler.new
+    subject.next = app.route_handler
     subject.call(context)
     response.close
     io.rewind
@@ -100,9 +97,8 @@ describe "Kemal::ExceptionHandler" do
       env.response.content_type = "application/json"
       env.response.status_code = 500
     end
-    context.app = app
-    subject = Kemal::ExceptionHandler.new(Kemal::Base.new)
-    subject.next = Kemal::RouteHandler.new
+    subject = Kemal::ExceptionHandler.new(app)
+    subject.next = app.route_handler
     subject.call(context)
     response.close
     io.rewind
diff --git a/spec/handler_spec.cr b/spec/handler_spec.cr
index 1b48ccc..85e2001 100644
--- a/spec/handler_spec.cr
+++ b/spec/handler_spec.cr
@@ -69,8 +69,8 @@ end
 
 describe "Handler" do
   it "adds custom handler before before_*" do
-    filter_middleware = Kemal::FilterHandler.new
-    Kemal.application.add_filter_handler filter_middleware
+    app = Kemal::Base.new
+    filter_middleware = Kemal::FilterHandler.new(app)
     filter_middleware._add_route_filter("GET", "/", :before) do |env|
       env.response << " is"
     end
@@ -78,7 +78,6 @@ describe "Handler" do
     filter_middleware._add_route_filter("GET", "/", :before) do |env|
       env.response << " so"
     end
-    app = Kemal::Base.new
     app.add_filter_handler filter_middleware
 
     app.add_handler CustomTestHandler.new
diff --git a/spec/middleware/filters_spec.cr b/spec/middleware/filters_spec.cr
index 65f1d48..6a5596a 100644
--- a/spec/middleware/filters_spec.cr
+++ b/spec/middleware/filters_spec.cr
@@ -5,7 +5,7 @@ describe "Kemal::FilterHandler" do
     test_filter = FilterTest.new
     test_filter.modified = "false"
 
-    filter_middleware = Kemal::FilterHandler.new
+    filter_middleware = Kemal::FilterHandler.new(Kemal.application)
     filter_middleware._add_route_filter("GET", "/greetings", :before) { test_filter.modified = "true" }
 
     kemal = Kemal.application.route_handler
@@ -23,7 +23,7 @@ describe "Kemal::FilterHandler" do
     test_filter = FilterTest.new
     test_filter.modified = "false"
 
-    filter_middleware = Kemal::FilterHandler.new
+    filter_middleware = Kemal::FilterHandler.new(Kemal.application)
     filter_middleware._add_route_filter("GET", "/greetings", :before) { test_filter.modified = test_filter.modified == "true" ? "false" : "true" }
 
     kemal = Kemal.application.route_handler
@@ -49,7 +49,7 @@ describe "Kemal::FilterHandler" do
     test_filter = FilterTest.new
     test_filter.modified = "false"
 
-    filter_middleware = Kemal::FilterHandler.new
+    filter_middleware = Kemal::FilterHandler.new(Kemal.application)
     filter_middleware._add_route_filter("ALL", "/greetings", :before) { test_filter.modified = test_filter.modified == "true" ? "false" : "true" }
     filter_middleware._add_route_filter("GET", "/greetings", :before) { test_filter.modified = test_filter.modified == "true" ? "false" : "true" }
     filter_middleware._add_route_filter("POST", "/greetings", :before) { test_filter.modified = test_filter.modified == "true" ? "false" : "true" }
@@ -77,7 +77,7 @@ describe "Kemal::FilterHandler" do
     test_filter = FilterTest.new
     test_filter.modified = "false"
 
-    filter_middleware = Kemal::FilterHandler.new
+    filter_middleware = Kemal::FilterHandler.new(Kemal.application)
     filter_middleware._add_route_filter("GET", "/greetings", :after) { test_filter.modified = "true" }
 
     kemal = Kemal.application.route_handler
@@ -95,7 +95,7 @@ describe "Kemal::FilterHandler" do
     test_filter = FilterTest.new
     test_filter.modified = "false"
 
-    filter_middleware = Kemal::FilterHandler.new
+    filter_middleware = Kemal::FilterHandler.new(Kemal.application)
     filter_middleware._add_route_filter("GET", "/greetings", :after) { test_filter.modified = test_filter.modified == "true" ? "false" : "true" }
 
     kemal = Kemal.application.route_handler
@@ -121,7 +121,7 @@ describe "Kemal::FilterHandler" do
     test_filter = FilterTest.new
     test_filter.modified = "false"
 
-    filter_middleware = Kemal::FilterHandler.new
+    filter_middleware = Kemal::FilterHandler.new(Kemal.application)
     filter_middleware._add_route_filter("ALL", "/greetings", :after) { test_filter.modified = test_filter.modified == "true" ? "false" : "true" }
     filter_middleware._add_route_filter("GET", "/greetings", :after) { test_filter.modified = test_filter.modified == "true" ? "false" : "true" }
     filter_middleware._add_route_filter("POST", "/greetings", :after) { test_filter.modified = test_filter.modified == "true" ? "false" : "true" }
@@ -152,7 +152,7 @@ describe "Kemal::FilterHandler" do
     test_filter_third = FilterTest.new
     test_filter_third.modified = "false"
 
-    filter_middleware = Kemal::FilterHandler.new
+    filter_middleware = Kemal::FilterHandler.new(Kemal.application)
     filter_middleware._add_route_filter("ALL", "/greetings", :before) { test_filter.modified = test_filter.modified == "true" ? "false" : "true" }
     filter_middleware._add_route_filter("ALL", "/greetings", :before) { test_filter_second.modified = test_filter_second.modified == "true" ? "false" : "true" }
     filter_middleware._add_route_filter("ALL", "/greetings", :before) { test_filter_third.modified = test_filter_third.modified == "true" ? "false" : "true" }
diff --git a/spec/websocket_handler_spec.cr b/spec/websocket_handler_spec.cr
index cbcb34e..e89dcc5 100644
--- a/spec/websocket_handler_spec.cr
+++ b/spec/websocket_handler_spec.cr
@@ -1,6 +1,6 @@
 require "./spec_helper"
 
-private def create_ws_request_and_return_io(handler, request, app)
+private def create_ws_request_and_return_io(handler, request, app = Kemal.application)
   io = IO::Memory.new
   response = HTTP::Server::Response.new(io)
   context = HTTP::Server::Context.new(request, response)
@@ -16,8 +16,8 @@ end
 describe "Kemal::WebSocketHandler" do
   it "doesn't match on wrong route" do
     app = Kemal::Base.new
-    handler = Kemal::WebSocketHandler.new
-    handler.next = Kemal::RouteHandler.new
+    handler = app.websocket_handler
+    handler.next = app.route_handler
     app.ws "/" { }
     headers = HTTP::Headers{
       "Upgrade"           => "websocket",
@@ -28,7 +28,6 @@ describe "Kemal::WebSocketHandler" do
     io = IO::Memory.new
     response = HTTP::Server::Response.new(io)
     context = HTTP::Server::Context.new(request, response)
-    context.app = app
 
     expect_raises(Kemal::Exceptions::RouteNotFound) do
       handler.call context
@@ -37,7 +36,7 @@ describe "Kemal::WebSocketHandler" do
 
   it "matches on given route" do
     app = Kemal::Base.new
-    handler = Kemal::WebSocketHandler.new
+    handler =  app.websocket_handler
     app.ws "/" { |socket, context| socket.send("Match") }
     app.ws "/no_match" { |socket, context| socket.send "No Match" }
     headers = HTTP::Headers{
@@ -54,7 +53,7 @@ describe "Kemal::WebSocketHandler" do
 
   it "fetches named url parameters" do
     app = Kemal::Base.new
-    handler = Kemal::WebSocketHandler.new
+    handler =  app.websocket_handler
     app.ws "/:id" { |s, c| c.params.url["id"] }
     headers = HTTP::Headers{
       "Upgrade"               => "websocket",
@@ -69,15 +68,14 @@ describe "Kemal::WebSocketHandler" do
 
   it "matches correct verb" do
     app = Kemal::Base.new
-    handler = Kemal::WebSocketHandler.new
-    handler.next = Kemal::RouteHandler.new
+    handler =  app.websocket_handler
+    handler.next =  app.route_handler
     app.ws "/" { }
     app.get "/" { "get" }
     request = HTTP::Request.new("GET", "/")
     io = IO::Memory.new
     response = HTTP::Server::Response.new(io)
     context = HTTP::Server::Context.new(request, response)
-    context.app = app
     handler.call(context)
     response.close
     io.rewind
diff --git a/src/kemal/base.cr b/src/kemal/base.cr
index db3b078..a4b205d 100644
--- a/src/kemal/base.cr
+++ b/src/kemal/base.cr
@@ -15,18 +15,19 @@ class Kemal::Base
   include Base::Builder
 
   # :nodoc:
-  getter route_handler = Kemal::RouteHandler.new
+  # TODO: These ivars are initialized in the constructor, but their values depend on `self`.
+  getter! route_handler : RouteHandler?
   # :nodoc:
-  getter filter_handler = Kemal::FilterHandler.new
+  getter! filter_handler : FilterHandler?
   # :nodoc:
-  getter websocket_handler = Kemal::WebSocketHandler.new
+  getter! websocket_handler : WebSocketHandler?
 
   getter handlers = [] of HTTP::Handler
   getter error_handlers = {} of Int32 => HTTP::Server::Context, Exception -> String
 
   getter config : Config
 
-  property! logger : Kemal::BaseLogHandler
+  property! logger : BaseLogHandler
   property! server : HTTP::Server
   property? running = false
 
diff --git a/src/kemal/exception_handler.cr b/src/kemal/exception_handler.cr
index 32da24b..98a8643 100644
--- a/src/kemal/exception_handler.cr
+++ b/src/kemal/exception_handler.cr
@@ -19,16 +19,16 @@ module Kemal
         call_exception_with_status_code(context, ex, context.response.status_code)
       rescue ex : Exception
         log("Exception: #{ex.inspect_with_backtrace}")
-        return call_exception_with_status_code(context, ex, 500) if context.app.error_handlers.has_key?(500)
-        verbosity = context.app.config.env == "production" ? false : true
+        return call_exception_with_status_code(context, ex, 500) if app.error_handlers.has_key?(500)
+        verbosity = app.config.env == "production" ? false : true
         return app.render_500(context, ex.inspect_with_backtrace, verbosity)
       end
     end
 
     private def call_exception_with_status_code(context, exception, status_code)
-      if context.app.error_handlers.has_key?(status_code)
+      if !app.error_handlers.empty? && app.error_handlers.has_key?(status_code)
         context.response.content_type = "text/html" unless context.response.headers.has_key?("Content-Type")
-        context.response.print context.app.error_handlers[status_code].call(context, exception)
+        context.response.print app.error_handlers[status_code].call(context, exception)
         context.response.status_code = status_code
         context
       end
diff --git a/src/kemal/filter_handler.cr b/src/kemal/filter_handler.cr
index a135744..f6c5894 100644
--- a/src/kemal/filter_handler.cr
+++ b/src/kemal/filter_handler.cr
@@ -3,17 +3,19 @@ module Kemal
   class FilterHandler
     include HTTP::Handler
 
+    getter app : Kemal::Base
+
     # This middleware is lazily instantiated and added to the handlers as soon as a call to `after_X` or `before_X` is made.
-    def initialize
+    def initialize(@app)
       @tree = Radix::Tree(Array(FilterBlock)).new
     end
 
-    # The call order of the filters is `before_all -> before_x -> X -> after_x -> after_all`.
+    # The call order of the filters is before_all -> before_x -> X -> after_x -> after_all
     def call(context : HTTP::Server::Context)
-      return call_next(context) unless context.route_found?
+      return call_next(context) unless app.route_handler.route_defined?(context.request)
       call_block_for_path_type("ALL", context.request.path, :before, context)
       call_block_for_path_type(context.request.override_method, context.request.path, :before, context)
-      if context.app.error_handlers.has_key?(context.response.status_code)
+      if !app.error_handlers.empty? && app.error_handlers.has_key?(context.response.status_code)
         raise Kemal::Exceptions::CustomException.new(context)
       end
       call_next(context)
diff --git a/src/kemal/helpers/file_helpers.cr b/src/kemal/helpers/file_helpers.cr
index 375439c..b0a5636 100644
--- a/src/kemal/helpers/file_helpers.cr
+++ b/src/kemal/helpers/file_helpers.cr
@@ -49,7 +49,7 @@ module Kemal::FileHelpers
   end
 
   def send_file(env, path : String, mime_type : String? = nil)
-    send_file(env, path, env.app.config, mime_type)
+    send_file(env, path, config, mime_type)
   end
 
   private def multipart(file, env : HTTP::Server::Context)
diff --git a/src/kemal/route_handler.cr b/src/kemal/route_handler.cr
index fd2f672..ca7f3c8 100644
--- a/src/kemal/route_handler.cr
+++ b/src/kemal/route_handler.cr
@@ -8,7 +8,9 @@ module Kemal
     CACHED_ROUTES_LIMIT = 1024
     property routes, cached_routes
 
-    def initialize
+    getter app : Kemal::Base
+
+    def initialize(@app)
       @routes = Radix::Tree(Route).new
       @cached_routes = Hash(String, Radix::Result(Route)).new
     end
@@ -42,12 +44,20 @@ module Kemal
       route
     end
 
+    def lookup_route(request)
+      lookup_route request.override_method.as(String), request.path
+    end
+
+    def route_defined?(request)
+      lookup_route(request).found?
+    end
+
     # Processes the route if it's a match. Otherwise renders 404.
     private def process_request(context)
       raise Kemal::Exceptions::RouteNotFound.new(context) unless context.route_found?
       content = context.route.handler.call(context)
 
-      if context.app.error_handlers.has_key?(context.response.status_code)
+      if !app.error_handlers.empty? && app.error_handlers.has_key?(context.response.status_code)
         raise Kemal::Exceptions::CustomException.new(context)
       end
 
diff --git a/src/kemal/websocket_handler.cr b/src/kemal/websocket_handler.cr
index da81b2f..a2515d3 100644
--- a/src/kemal/websocket_handler.cr
+++ b/src/kemal/websocket_handler.cr
@@ -4,13 +4,17 @@ module Kemal
 
     property routes
 
-    def initialize
+    getter app : Kemal::Base
+
+    def initialize(@app)
       @routes = Radix::Tree(WebSocket).new
     end
 
     def call(context : HTTP::Server::Context)
-      return call_next(context) unless context.ws_route_found? && websocket_upgrade_request?(context)
-      content = context.websocket.call(context)
+      route = lookup_ws_route(context.request.path)
+      return call_next(context) unless route.found? && websocket_upgrade_request?(context)
+      context.request.url_params ||= route.params
+      content = route.payload.call(context)
       context.response.print(content)
       context
     end