diff --git a/commands/build.v b/commands/build.v
index f45de6d..3b0351f 100644
--- a/commands/build.v
+++ b/commands/build.v
@@ -1,15 +1,12 @@
 module commands
 
 import os
-import cli
 import log
 import time
 import markdown
 import internal.template
 import internal.config
 
-const default_config = 'config.toml'
-
 const default_template = 'layouts/index.html'
 
 const defautl_static = 'static'
@@ -18,7 +15,7 @@ const default_index = 'index.md'
 
 const default_dist = 'dist'
 
-struct Builder {
+struct BuildCommand {
 mut:
 	config           config.Config
 	logger           log.Log
@@ -28,29 +25,14 @@ mut:
 	config_map       map[string]string
 }
 
-fn new_builder(logger log.Log) Builder {
-	return Builder{
+// new_build_cmd create new build command instance.
+pub fn new_build_cmd(conf config.Config, logger log.Log) BuildCommand {
+	return BuildCommand{
+		config: conf
 		logger: logger
 		dist: commands.default_dist
 		static_dir: commands.defautl_static
-	}
-}
-
-// new_build_cmd returns a cli.Command for build command
-pub fn new_build_cmd() cli.Command {
-	return cli.Command{
-		name: 'build'
-		description: 'build your site'
-		usage: 'vss build'
-		execute: fn (cmd cli.Command) ! {
-			mut logger := log.Log{}
-			logger.set_level(log.Level.info)
-			conf := load_config(commands.default_config)!
-			build(conf, mut logger) or {
-				logger.error(err.msg())
-				println('Build failed')
-			}
-		}
+		config_map: conf.as_map()
 	}
 }
 
@@ -89,7 +71,7 @@ fn check_layout(path string) bool {
 	return true
 }
 
-fn (mut b Builder) md2html(md_path string) ! {
+fn (mut b BuildCommand) md2html(md_path string) ! {
 	// get html body content from md
 	b.logger.info('start md to html: ${md_path}')
 	content := get_content(md_path)!
@@ -119,21 +101,15 @@ fn (mut b Builder) md2html(md_path string) ! {
 	os.write_file(dist_path, html)!
 }
 
-// load_config loads a toml config file
-fn load_config(toml_file string) !config.Config {
-	toml_text := os.read_file(toml_file)!
-	return config.load(toml_text)
-}
-
 // copy_static copy static files to dist
-fn (b Builder) copy_static() ! {
+fn (b BuildCommand) copy_static() ! {
 	if os.exists(b.static_dir) {
 		os.cp_all(b.static_dir, b.dist, false)!
 	}
 }
 
 // create_dist_dir create build output destination
-fn (mut b Builder) create_dist_dir() ! {
+fn (mut b BuildCommand) create_dist_dir() ! {
 	if os.exists(b.dist) {
 		b.logger.info('re-create dist dir')
 		os.rmdir_all(b.dist)!
@@ -144,7 +120,7 @@ fn (mut b Builder) create_dist_dir() ! {
 	}
 }
 
-fn (mut b Builder) is_ignore(path string) bool {
+fn (mut b BuildCommand) is_ignore(path string) bool {
 	// e.g. README.md
 	file_name := os.file_name(path)
 	// notify user that build was skipped
@@ -154,30 +130,33 @@ fn (mut b Builder) is_ignore(path string) bool {
 	return false
 }
 
-fn build(conf config.Config, mut logger log.Log) ! {
+fn (mut b BuildCommand) set_base_url(url string) {
+	b.config.base_url = url
+	b.config_map['base_url'] = url
+}
+
+// run build command main process
+pub fn (mut b BuildCommand) run() ! {
 	println('Start building')
 	mut sw := time.new_stopwatch()
-	mut b := new_builder(logger)
 	template_content := os.read_file(commands.default_template)!
 	b.template_content = template_content
-	b.config = conf
-	b.config_map = conf.as_map()
 
 	b.create_dist_dir()!
 	// copy static dir files
-	logger.info('copy static files')
+	b.logger.info('copy static files')
 	b.copy_static()!
 
 	mds := normalise_paths(os.walk_ext('.', '.md'))
-	logger.info('start md to html')
+	b.logger.info('start md to html')
 	for path in mds {
 		if b.is_ignore(path) {
-			logger.info('${path} is included in ignore_files, skip build')
+			b.logger.info('${path} is included in ignore_files, skip build')
 			continue
 		}
 		b.md2html(path)!
 	}
-	logger.info('end md to html')
+	b.logger.info('end md to html')
 
 	sw.stop()
 	println('Total in ' + sw.elapsed().milliseconds().str() + ' ms')
diff --git a/commands/serve.v b/commands/serve.v
index 6faf90d..dc8627c 100644
--- a/commands/serve.v
+++ b/commands/serve.v
@@ -1,6 +1,5 @@
 module commands
 
-import cli
 import log
 import net.http
 import os
@@ -8,20 +7,19 @@ import internal.config
 
 const cport = 8080
 
-// new_serve_cmd returns a cli.Command for serve command
-pub fn new_serve_cmd() cli.Command {
-	return cli.Command{
-		name: 'serve'
-		description: 'serve dist'
-		usage: 'vss serve'
-		execute: fn (cmd cli.Command) ! {
-			mut logger := log.Log{}
-			logger.set_level(log.Level.info)
-			serve(mut logger) or {
-				logger.error(err.msg())
-				println('serve failed')
-			}
-		}
+struct ServeCommand {
+mut:
+	logger   log.Log
+	port     int
+	buildcmd BuildCommand
+}
+
+// new_serve_cmd creates a new ServeCommand instance.
+pub fn new_serve_cmd(conf config.Config, logger log.Log) ServeCommand {
+	return ServeCommand{
+		logger: logger
+		port: commands.cport
+		buildcmd: new_build_cmd(conf, logger)
 	}
 }
 
@@ -74,7 +72,7 @@ mut:
 	time_stamp i64
 }
 
-fn watch(path string, conf config.Config, mut logger log.Log) {
+fn (mut s ServeCommand) watch(path string) {
 	mut res := []string{}
 	os.walk_with_context(path, &res, fn (mut res []string, fpath string) {
 		res << fpath
@@ -100,8 +98,8 @@ fn watch(path string, conf config.Config, mut logger log.Log) {
 				println('modified file: ${w.path}')
 				w.time_stamp = now
 
-				build(conf, mut logger) or {
-					logger.error(err.msg())
+				s.build() or {
+					s.logger.error(err.msg())
 					println('Build failed')
 				}
 			}
@@ -109,7 +107,12 @@ fn watch(path string, conf config.Config, mut logger log.Log) {
 	}
 }
 
-fn serve(mut logger log.Log) ! {
+fn (mut s ServeCommand) build() ! {
+	s.buildcmd.run()!
+}
+
+// run serve command main process.
+pub fn (mut s ServeCommand) run() ! {
 	mut handler := MyHttpHandler{
 		root: 'dist'
 	}
@@ -118,18 +121,18 @@ fn serve(mut logger log.Log) ! {
 		port: commands.cport
 	}
 
+	// base_url を localhost にする
 	local_base_url := 'http://localhost:${commands.cport}/'
-	mut conf := load_config(default_config)!
-	conf.base_url = local_base_url
-	println(local_base_url)
+	s.buildcmd.set_base_url(local_base_url)
 
-	// build before server startup
-	build(conf, mut logger) or {
-		logger.error(err.msg())
-		println('Build failed')
+	// build
+	s.build() or {
+		s.logger.error(err.msg())
+		println('build failed')
 	}
 
-	w := spawn watch('.', conf, mut logger)
+	println(local_base_url)
+	w := spawn s.watch('.')
 	server.listen_and_serve()
 
 	w.wait()
diff --git a/main.v b/main.v
index 4898211..617a96c 100644
--- a/main.v
+++ b/main.v
@@ -2,26 +2,69 @@ module main
 
 import os
 import cli
+import log
 import commands
+import internal.config
 
 const version = '0.3.0'
 
-fn main() {
-	mut app := cli.Command{
+const default_config = 'config.toml'
+
+// load_config loads a toml config file
+fn load_config(toml_file string) !config.Config {
+	toml_text := os.read_file(toml_file)!
+	return config.load(toml_text)
+}
+
+fn init_logger() log.Log {
+	return log.Log{
+		level: log.Level.info
+	}
+}
+
+fn init_commands() cli.Command {
+	return cli.Command{
 		name: 'vss'
 		version: version
 		description: 'static site generator'
 		execute: fn (cmd cli.Command) ! {
 			println(cmd.help_message())
 		}
+		commands: [
+			cli.Command{
+				name: 'build'
+				description: 'build your site'
+				usage: 'vss build'
+				execute: fn (cmd cli.Command) ! {
+					mut logger := init_logger()
+					conf := load_config(default_config)!
+					mut c := commands.new_build_cmd(conf, logger)
+					c.run() or {
+						logger.error(err.msg())
+						println('build failed')
+					}
+				}
+			},
+			cli.Command{
+				name: 'serve'
+				description: 'serve dist'
+				usage: 'vss serve'
+				execute: fn (cmd cli.Command) ! {
+					mut logger := init_logger()
+					conf := load_config(default_config)!
+					mut c := commands.new_serve_cmd(conf, logger)
+					c.run() or {
+						logger.error(err.msg())
+						println('serve failed')
+					}
+				}
+			},
+		]
 	}
+}
 
-	// add commands
-	app.add_command(commands.new_build_cmd())
-	app.add_command(commands.new_serve_cmd())
-
+fn main() {
+	mut app := init_commands()
 	app.setup()
-
-	// run the app
 	app.parse(os.args)
 }