diff --git a/Gemfile b/Gemfile
new file mode 100644
index 00000000..019be792
--- /dev/null
+++ b/Gemfile
@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+# Gemfile
+ruby '3.3.3'
+source 'https://rubygems.org'
+
+gem 'puma'
+gem 'rack'
+gem 'rackup'
+gem 'rubocop', require: false
+gem 'sequel'
+gem 'sqlite3'
diff --git a/Gemfile.lock b/Gemfile.lock
new file mode 100644
index 00000000..8d0d87c3
--- /dev/null
+++ b/Gemfile.lock
@@ -0,0 +1,52 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    ast (2.4.2)
+    bigdecimal (3.2.0)
+    json (2.11.3)
+    nio4r (2.7.4)
+    parallel (1.23.0)
+    parser (3.2.2.1)
+      ast (~> 2.4.1)
+    puma (6.6.0)
+      nio4r (~> 2.0)
+    rack (3.1.15)
+    rackup (2.2.1)
+      rack (>= 3)
+    rainbow (3.1.1)
+    regexp_parser (2.10.0)
+    rexml (3.4.1)
+    rubocop (1.50.2)
+      json (~> 2.3)
+      parallel (~> 1.10)
+      parser (>= 3.2.0.0)
+      rainbow (>= 2.2.2, < 4.0)
+      regexp_parser (>= 1.8, < 3.0)
+      rexml (>= 3.2.5, < 4.0)
+      rubocop-ast (>= 1.28.0, < 2.0)
+      ruby-progressbar (~> 1.7)
+      unicode-display_width (>= 2.4.0, < 3.0)
+    rubocop-ast (1.28.1)
+      parser (>= 3.2.1.0)
+    ruby-progressbar (1.13.0)
+    sequel (5.92.0)
+      bigdecimal
+    sqlite3 (1.7.3-arm64-darwin)
+    unicode-display_width (2.4.2)
+
+PLATFORMS
+  arm64-darwin-24
+
+DEPENDENCIES
+  puma
+  rack
+  rackup
+  rubocop
+  sequel
+  sqlite3
+
+RUBY VERSION
+   ruby 3.3.3p89
+
+BUNDLED WITH
+   2.6.9
diff --git a/app/controllers/tests_controller.rb b/app/controllers/tests_controller.rb
index 1526a689..222884a8 100644
--- a/app/controllers/tests_controller.rb
+++ b/app/controllers/tests_controller.rb
@@ -1,11 +1,21 @@
-class TestsController < Simpler::Controller
+# frozen_string_literal: true
 
+class TestsController < Simpler::Controller
   def index
     @time = Time.now
   end
 
   def create
+    render json: { message: 'Created successfully' }, status: 201
+  end
 
+  def plain
+    headers['X-Time-Header'] = Time.now.to_s
+    render plain: "Time.now: #{Time.now}\n"
   end
 
+  def show
+    @test_id = params[:id]
+    render plain: "Test ID: #{@test_id}"
+  end
 end
diff --git a/app/models/test.rb b/app/models/test.rb
index 86376668..db135e04 100644
--- a/app/models/test.rb
+++ b/app/models/test.rb
@@ -1,8 +1,9 @@
+# frozen_string_literal: true
+
 # Simpler.application.db.create_table(:tests) do
 #   primary_key :id
 #   String :title, null: false
 #   Integer :level, default: 0
 # end
 class Test < Sequel::Model
-
 end
diff --git a/config.ru b/config.ru
index 3060cc20..c92e3187 100644
--- a/config.ru
+++ b/config.ru
@@ -1,3 +1,6 @@
-require_relative 'config/environment'
+# frozen_string_literal: true
 
+require_relative './config/environment'
+
+use Simpler::Middleware::Logger
 run Simpler.application
diff --git a/config/environment.rb b/config/environment.rb
index 7a0d38c3..c037546f 100644
--- a/config/environment.rb
+++ b/config/environment.rb
@@ -1,3 +1,6 @@
+# frozen_string_literal: true
+
+require_relative '../lib/simpler/middleware/logger'
 require_relative '../lib/simpler'
 
 Simpler.application.bootstrap!
diff --git a/config/routes.rb b/config/routes.rb
index 4a751251..55ad3d6f 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -1,4 +1,8 @@
+# frozen_string_literal: true
+
 Simpler.application.routes do
   get '/tests', 'tests#index'
+  get '/tests/plain', 'tests#plain'
   post '/tests', 'tests#create'
+  get '/tests/:id', 'tests#show'
 end
diff --git a/lib/simpler.rb b/lib/simpler.rb
index f9dfe3c4..6fb23105 100644
--- a/lib/simpler.rb
+++ b/lib/simpler.rb
@@ -1,8 +1,9 @@
+# frozen_string_literal: true
+
 require 'pathname'
 require_relative 'simpler/application'
 
 module Simpler
-
   class << self
     def application
       Application.instance
@@ -12,5 +13,4 @@ def root
       Pathname.new(File.expand_path('..', __dir__))
     end
   end
-
 end
diff --git a/lib/simpler/application.rb b/lib/simpler/application.rb
index 711946a9..f763233a 100644
--- a/lib/simpler/application.rb
+++ b/lib/simpler/application.rb
@@ -1,3 +1,6 @@
+# frozen_string_literal: true
+
+require 'rack'
 require 'yaml'
 require 'singleton'
 require 'sequel'
@@ -6,7 +9,6 @@
 
 module Simpler
   class Application
-
     include Singleton
 
     attr_reader :db
@@ -28,10 +30,13 @@ def routes(&block)
 
     def call(env)
       route = @router.route_for(env)
-      controller = route.controller.new(env)
-      action = route.action
-
-      make_response(controller, action)
+      if route.nil?
+        not_found_response
+      else
+        controller = route.controller.new(env)
+        action = route.action
+        make_response(controller, action)
+      end
     end
 
     private
@@ -50,9 +55,20 @@ def setup_database
       @db = Sequel.connect(database_config)
     end
 
+    def not_found_response
+      build_error_response(404, 'Not Found')
+    end
+
+    def build_error_response(status, body)
+      Rack::Response.new do |res|
+        res.status = status
+        res['Content-Type'] = 'text/plain'
+        res.write(body)
+      end.finish
+    end
+
     def make_response(controller, action)
       controller.make_response(action)
     end
-
   end
 end
diff --git a/lib/simpler/controller.rb b/lib/simpler/controller.rb
index 9383b035..7a514d70 100644
--- a/lib/simpler/controller.rb
+++ b/lib/simpler/controller.rb
@@ -1,14 +1,17 @@
+# frozen_string_literal: true
+
+require 'json'
 require_relative 'view'
 
 module Simpler
   class Controller
-
     attr_reader :name, :request, :response
 
     def initialize(env)
       @name = extract_name
       @request = Rack::Request.new(env)
       @response = Rack::Response.new
+      @env = env
     end
 
     def make_response(action)
@@ -22,6 +25,10 @@ def make_response(action)
       @response.finish
     end
 
+    def headers
+      @response.headers
+    end
+
     private
 
     def extract_name
@@ -29,26 +36,67 @@ def extract_name
     end
 
     def set_default_headers
-      @response['Content-Type'] = 'text/html'
+      @response['Content-Type'] ||= 'text/html'
     end
 
     def write_response
-      body = render_body
-
-      @response.write(body)
+      @response.write(render_body)
     end
 
     def render_body
-      View.new(@request.env).render(binding)
+      return render_json   if json_response?
+      return render_plain  if plain_response?
+
+      render_template
     end
 
-    def params
-      @request.params
+    def plain_response?
+      @env.key?('simpler.plain')
+    end
+
+    def json_response?
+      @env.key?('simpler.json')
     end
 
-    def render(template)
-      @request.env['simpler.template'] = template
+    def render_plain
+      @response['Content-Type'] = 'text/plain'
+      @env['simpler.plain']
     end
 
+    def render_json
+      @response['Content-Type'] = 'application/json'
+      JSON.generate(@env['simpler.json'])
+    end
+
+    def render_template
+      View.new(@env).render(binding)
+    end
+
+    def params
+      return @params if @params
+
+      @params = @request.params.transform_keys(&:to_sym)
+      route_params = @env['simpler.route_params']&.transform_keys(&:to_sym)
+      @params.merge!(route_params) if route_params
+      @params
+    end
+
+    def render(options)
+      case options
+      when String, Symbol
+        @env['simpler.template'] = options.to_s
+      when Hash
+        @response.status = options.delete(:status) if options.key?(:status)
+        if options[:plain]
+          @env['simpler.plain'] = options[:plain].to_s
+        elsif options[:json]
+          @env['simpler.json'] = options[:json]
+        else
+          raise ArgumentError, "Unknown render option: #{options.keys.join(', ')}"
+        end
+      else
+        raise ArgumentError, "Invalid argument for render: #{options.inspect}"
+      end
+    end
   end
 end
diff --git a/lib/simpler/middleware/logger.rb b/lib/simpler/middleware/logger.rb
new file mode 100644
index 00000000..48f57c5e
--- /dev/null
+++ b/lib/simpler/middleware/logger.rb
@@ -0,0 +1,74 @@
+# frozen_string_literal: true
+
+require 'logger'
+require 'fileutils'
+
+module Simpler
+  module Middleware
+    class Logger
+      LOG_FILE = 'log/app.log'
+
+      def initialize(app)
+        @app = app
+        ensure_log_directory
+        @logger = setup_logger
+      end
+
+      def call(env)
+        start = Time.now
+        status, headers, body = @app.call(env)
+
+        log_request(env)
+        log_response(status, headers, env)
+
+        [status, headers, body]
+      end
+
+      private
+
+      def ensure_log_directory
+        FileUtils.mkdir_p(File.dirname(LOG_FILE))
+      end
+
+      def setup_logger
+        ::Logger.new(LOG_FILE, 'daily')
+      end
+
+      def log_request(env)
+        request = Rack::Request.new(env)
+        controller = env['simpler.controller']
+        action = env['simpler.action']
+
+        message = []
+        message << "Request: #{env['REQUEST_METHOD']} #{env['PATH_INFO']}#{env['QUERY_STRING'].empty? ? '' : "?#{env['QUERY_STRING']}"}"
+        message << "Handler: #{controller.class.name}##{action}" if controller && action
+        message << "Parameters: #{collect_parameters(request, env)}"
+
+        @logger.info(message.join("\n"))
+      end
+
+      def log_response(status, headers, env)
+        message = "Response: #{status} #{Rack::Utils::HTTP_STATUS_CODES[status]}"
+        message << " [#{headers['Content-Type']}]"
+        message << " #{env['simpler.template']}" if env['simpler.template']
+
+        @logger.info(message)
+      end
+
+      def collect_parameters(request, env)
+        params = {}
+
+        # Query parameters
+        params.merge!(request.GET)
+
+        # POST parameters
+        params.merge!(request.POST) if request.post?
+
+        # Route parameters
+        params.merge!(env['simpler.route_params'] || {})
+
+        params
+      end
+    end
+  end
+end
diff --git a/lib/simpler/router.rb b/lib/simpler/router.rb
index 14b3415c..816ed98a 100644
--- a/lib/simpler/router.rb
+++ b/lib/simpler/router.rb
@@ -1,8 +1,9 @@
+# frozen_string_literal: true
+
 require_relative 'router/route'
 
 module Simpler
   class Router
-
     def initialize
       @routes = []
     end
@@ -19,15 +20,18 @@ def route_for(env)
       method = env['REQUEST_METHOD'].downcase.to_sym
       path = env['PATH_INFO']
 
-      @routes.find { |route| route.match?(method, path) }
+      route = @routes.find { |r| r.match?(method, path) }
+      return unless route
+
+      env['simpler.route_params'] = route.extract_params(path)
+      route
     end
 
     private
 
     def add_route(method, path, route_point)
-      route_point = route_point.split('#')
-      controller = controller_from_string(route_point[0])
-      action = route_point[1]
+      controller_name, action = route_point.split('#')
+      controller = controller_from_string(controller_name)
       route = Route.new(method, path, controller, action)
 
       @routes.push(route)
@@ -36,6 +40,5 @@ def add_route(method, path, route_point)
     def controller_from_string(controller_name)
       Object.const_get("#{controller_name.capitalize}Controller")
     end
-
   end
 end
diff --git a/lib/simpler/router/route.rb b/lib/simpler/router/route.rb
index 4c66b4b7..12a4abcc 100644
--- a/lib/simpler/router/route.rb
+++ b/lib/simpler/router/route.rb
@@ -1,20 +1,53 @@
+# frozen_string_literal: true
+
 module Simpler
   class Router
     class Route
-
-      attr_reader :controller, :action
+      attr_reader :controller, :action, :params_pattern
 
       def initialize(method, path, controller, action)
         @method = method
-        @path = path
+        @path = normalize_path(path)
         @controller = controller
         @action = action
+        @params_pattern = build_params_pattern(path)
+      end
+
+      def match?(method, request_path)
+        @method == method && path_match?(normalize_path(request_path))
       end
 
-      def match?(method, path)
-        @method == method && path.match(@path)
+      def extract_params(request_path)
+        return {} unless @params_pattern
+
+        matches = normalize_path(request_path).match(@params_pattern)
+        return {} unless matches
+
+        matches.named_captures.transform_keys(&:to_sym)
       end
 
+      private
+
+      def normalize_path(path)
+        path.chomp('/')
+      end
+
+      def build_params_pattern(path)
+        return nil unless path.include?(':')
+
+        pattern = normalize_path(path).gsub(%r{:[^/]+}) do |match|
+          param_name = match[1..]
+          "(?<#{param_name}>[^\/]+)"
+        end
+
+        Regexp.new("^#{pattern}$")
+      end
+
+      def path_match?(request_path)
+        return request_path == @path unless @params_pattern
+
+        request_path.match?(@params_pattern)
+      end
     end
   end
 end
diff --git a/lib/simpler/view.rb b/lib/simpler/view.rb
index 19a73b34..5c6e7a25 100644
--- a/lib/simpler/view.rb
+++ b/lib/simpler/view.rb
@@ -1,9 +1,10 @@
+# frozen_string_literal: true
+
 require 'erb'
 
 module Simpler
   class View
-
-    VIEW_BASE_PATH = 'app/views'.freeze
+    VIEW_BASE_PATH = 'app/views'
 
     def initialize(env)
       @env = env
@@ -34,6 +35,5 @@ def template_path
 
       Simpler.root.join(VIEW_BASE_PATH, "#{path}.html.erb")
     end
-
   end
 end