diff --git a/src/kemal.cr b/src/kemal.cr
index 84155f6..088e897 100644
--- a/src/kemal.cr
+++ b/src/kemal.cr
@@ -2,6 +2,8 @@ require "./kemal/*"
 require "./kemal/middleware/*"
 
 module Kemal
+
+  # The command to run a `Kemal` application.
   def self.run
     Kemal::CLI.new
     config = Kemal.config
@@ -11,6 +13,7 @@ module Kemal
     config.server = HTTP::Server.new(config.host_binding.not_nil!, config.port, config.handlers)
     config.server.not_nil!.ssl = config.ssl
 
+    # Test environment doesn't need to have signal trap, built-in images, and logging.
     unless config.env == "test"
       Signal::INT.trap {
         config.logger.write "Kemal is going to take a rest!\n"
diff --git a/src/kemal/base_log_handler.cr b/src/kemal/base_log_handler.cr
index 040bab2..b2180e3 100644
--- a/src/kemal/base_log_handler.cr
+++ b/src/kemal/base_log_handler.cr
@@ -1,5 +1,6 @@
 require "http"
 
+# All loggers must inherit from `Kemal::BaseLogHandler`.
 class Kemal::BaseLogHandler < HTTP::Handler
   def initialize(@env : String)
   end
diff --git a/src/kemal/cli.cr b/src/kemal/cli.cr
index c74a9b2..5d235b0 100644
--- a/src/kemal/cli.cr
+++ b/src/kemal/cli.cr
@@ -1,6 +1,7 @@
 require "option_parser"
 
 module Kemal
+  # Handles all the initialization from the command line.
   class CLI
     @config : Kemal::Config
     @key_file : String
diff --git a/src/kemal/helpers.cr b/src/kemal/helpers.cr
index 9c1a411..6e3f7d1 100644
--- a/src/kemal/helpers.cr
+++ b/src/kemal/helpers.cr
@@ -5,7 +5,6 @@ require "kilt"
 # get '/' do
 #   render 'hello.ecr'
 # end
-
 macro render(filename, layout)
   content = render {{filename}}
   render {{layout}}
@@ -21,6 +20,7 @@ macro return_with(env, status_code = 200, response = "")
   next
 end
 
+# Adds given HTTP::Handler+ to handlers.
 def add_handler(handler)
   Kemal.config.add_handler handler
 end
@@ -31,6 +31,8 @@ def basic_auth(username, password)
   add_handler auth_handler
 end
 
+# Sets public folder from which the static assets will be served.
+# By default this is `/public` not `src/public`.
 def public_folder(path)
   Kemal.config.public_folder = path
 end
diff --git a/src/kemal/null_log_handler.cr b/src/kemal/null_log_handler.cr
index 07d9665..a69f5a5 100644
--- a/src/kemal/null_log_handler.cr
+++ b/src/kemal/null_log_handler.cr
@@ -1,2 +1,3 @@
+# This is here to represend the logger corresponding to Null Object Pattern.
 class Kemal::NullLogHandler < Kemal::BaseLogHandler
 end
diff --git a/src/kemal/websocket_handler.cr b/src/kemal/websocket_handler.cr
index 28e39ae..e570834 100644
--- a/src/kemal/websocket_handler.cr
+++ b/src/kemal/websocket_handler.cr
@@ -1,4 +1,4 @@
-# Kemal::WebSocketHandler is used for each define WebSocket route.
+# Kemal::WebSocketHandler is used for building a WebSocket route.
 # For each WebSocket route a new handler is created and registered to global handlers.
 class Kemal::WebSocketHandler < HTTP::WebSocketHandler
   def initialize(@path : String, &@proc : HTTP::WebSocket, HTTP::Server::Context -> Void)