diff --git a/Makefile b/Makefile
index 41a5d3d..066525b 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,5 @@
-EXECPATH = ./build/dist
+EXEC_PATH = ./build/dist
+BUILD_CMD = go build -o $(EXEC_PATH) -ldflags="-s -w"
 
 lint:
 	golangci-lint run
@@ -7,13 +8,16 @@ dev:
 	air
 
 build:
-	go build -ldflags="-s -w" -o $(EXECPATH) .
+	$(BUILD_CMD) ./cmd/cli
 
 run: build
-	$(EXECPATH) new
+	$(EXEC_PATH) new
 
-run-web:
-	go run main.go --web=t
+build-web:
+	$(BUILD_CMD) ./cmd/server
+
+run-web: build-web
+	$(EXEC_PATH)
 
 web:
 	cd client && npm run start
@@ -21,4 +25,7 @@ web:
 test:
 	go test -json  -count=1 ./... -coverpkg=./... -coverprofile coverage.out -covermode=atomic | gotestfmt && go tool cover -html coverage.out && rm coverage.out
 
-.PHONY: lint run dev run-web test build
+clean:
+	rm -rf ./build/
+
+.PHONY: lint run dev run-web test build build-web clean web
diff --git a/api/server.go b/api/server.go
index c00afb4..aa8c671 100644
--- a/api/server.go
+++ b/api/server.go
@@ -12,13 +12,11 @@ type Server struct {
 	Router *chi.Mux
 }
 
-func NewServer() *Server {
+func New() *Server {
 	s := &Server{Router: chi.NewRouter()}
 	s.Router.Use(middleware.Logger)
 	s.Router.Use(cors.Handler(cors.Options{
-		// AllowedOrigins:   []string{"https://foo.com"}, // Use this to allow specific origin hosts
-		AllowedOrigins: []string{"https://*", "http://*"},
-		// AllowOriginFunc:  func(r *http.Request, origin string) bool { return true },
+		AllowedOrigins:   []string{"https://*", "http://*"},
 		AllowedMethods:   []string{"GET", "POST", "PUT", "DELETE", "OPTIONS"},
 		AllowedHeaders:   []string{"Accept", "Authorization", "Content-Type", "X-CSRF-Token"},
 		ExposedHeaders:   []string{"Link"},
@@ -29,6 +27,7 @@ func NewServer() *Server {
 	return s
 }
 
+// ServeHTTP implements Handler for Server
 func (s Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	s.Router.ServeHTTP(w, r)
 }
diff --git a/cmd/new.go b/app/new.go
similarity index 70%
rename from cmd/new.go
rename to app/new.go
index dd38872..3973e81 100644
--- a/cmd/new.go
+++ b/app/new.go
@@ -1,4 +1,4 @@
-package cmd
+package app
 
 import (
 	"log"
@@ -9,9 +9,16 @@ import (
 	"github.com/rjNemo/go-pass-gen/passgen"
 )
 
+var (
+	// length of the generated password.
+	length int
+	// withNumbers is set to true if the new password must contain numbers.
+	withNumbers bool
+)
+
 func init() {
-	newPasswordCommand.Flags().IntVarP(&Length, "length", "l", 6, "password length")
-	newPasswordCommand.Flags().BoolVarP(&WithNumbers, "numbers", "n", false, "password should contain numbers")
+	newPasswordCommand.Flags().IntVarP(&length, "length", "l", 6, "password length")
+	newPasswordCommand.Flags().BoolVarP(&withNumbers, "numbers", "n", false, "password should contain numbers")
 	rootCommand.AddCommand(newPasswordCommand)
 }
 
@@ -20,7 +27,7 @@ var newPasswordCommand = &cobra.Command{Use: "new",
 	Short: "New Password",
 	Long:  "Create a secure password",
 	Run: func(cmd *cobra.Command, args []string) {
-		opts := passgen.Options{Length: Length, WithNumbers: WithNumbers}
+		opts := passgen.Options{Length: length, WithNumbers: withNumbers}
 		pg := passgen.New(opts.SetDefaults())
 		password := pg.NewPassword()
 		display(password)
diff --git a/cmd/root.go b/app/root.go
similarity index 87%
rename from cmd/root.go
rename to app/root.go
index 893e1f8..a240be2 100644
--- a/cmd/root.go
+++ b/app/root.go
@@ -1,5 +1,5 @@
-// Package cmd defines the command-line interface to passgen
-package cmd
+// Package app defines the command-line interface to passgen
+package app
 
 import (
 	"log"
diff --git a/cmd/cli/main.go b/cmd/cli/main.go
new file mode 100644
index 0000000..0a1990d
--- /dev/null
+++ b/cmd/cli/main.go
@@ -0,0 +1,9 @@
+package main
+
+import (
+	"github.com/rjNemo/go-pass-gen/app"
+)
+
+func main() {
+	app.Execute()
+}
diff --git a/cmd/flags.go b/cmd/flags.go
deleted file mode 100644
index 90bb2e6..0000000
--- a/cmd/flags.go
+++ /dev/null
@@ -1,8 +0,0 @@
-package cmd
-
-var (
-	// Length of the generated password.
-	Length int
-	// WithNumbers is set to true if the new password must contain numbers.
-	WithNumbers bool
-)
diff --git a/cmd/server/main.go b/cmd/server/main.go
new file mode 100644
index 0000000..09f84f5
--- /dev/null
+++ b/cmd/server/main.go
@@ -0,0 +1,14 @@
+package main
+
+import (
+	"log"
+
+	"github.com/rjNemo/go-pass-gen/api"
+)
+
+const port = ":8080"
+
+func main() {
+	log.Printf("Start passgen server on http://localhost%s\n", port)
+	log.Fatal(api.New().Start(port))
+}
diff --git a/main.go b/main.go
deleted file mode 100644
index f9ee862..0000000
--- a/main.go
+++ /dev/null
@@ -1,28 +0,0 @@
-package main
-
-import (
-	"flag"
-	"log"
-
-	"github.com/rjNemo/go-pass-gen/api"
-	"github.com/rjNemo/go-pass-gen/cmd"
-)
-
-func main() {
-	web := flag.Bool("web", false, "")
-	flag.Parse()
-
-	if *web {
-		serveWeb()
-		return
-	}
-	cli()
-}
-
-func cli() {
-	cmd.Execute()
-}
-
-func serveWeb() {
-	log.Fatal(api.NewServer().Start(":8080"))
-}
diff --git a/passgen/constants.go b/passgen/constants.go
deleted file mode 100644
index 14aea04..0000000
--- a/passgen/constants.go
+++ /dev/null
@@ -1,10 +0,0 @@
-package passgen
-
-const (
-	// LOWERCASE characters if latin alphabet
-	LOWERCASE string = "abcdefghijklmnopqrstuvwxyz"
-	// UPPERCASE characters if latin alphabet
-	UPPERCASE = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
-	// NUMBERS arabic
-	NUMBERS = "0123456789"
-)
diff --git a/passgen/passgen.go b/passgen/passgen.go
index e795530..d8dfaf0 100644
--- a/passgen/passgen.go
+++ b/passgen/passgen.go
@@ -5,6 +5,17 @@ import (
 	"math/rand"
 )
 
+const (
+	// lowercase characters in latin alphabet
+	lowercase string = "abcdefghijklmnopqrstuvwxyz"
+
+	// uppercase characters in latin alphabet
+	uppercase = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+
+	// numbers arabic
+	numbers = "0123456789"
+)
+
 // PasswordGenerator handles passwords creation.
 type PasswordGenerator struct {
 	characters []rune
@@ -35,9 +46,9 @@ func (p PasswordGenerator) generatePassword(length int) string {
 
 // shuffleCharacters randomizes the characters.
 func (p PasswordGenerator) shuffleCharacters(withNumbers bool) []rune {
-	letters := []rune(UPPERCASE + LOWERCASE)
+	letters := []rune(uppercase + lowercase)
 	if withNumbers {
-		letters = append(letters, []rune(NUMBERS)...)
+		letters = append(letters, []rune(numbers)...)
 	}
 	rand.Shuffle(len(letters), func(i, j int) { letters[i], letters[j] = letters[j], letters[i] })
 	return letters
diff --git a/passgen/passgen_test.go b/passgen/passgen_test.go
index a25bc6e..6be68d2 100644
--- a/passgen/passgen_test.go
+++ b/passgen/passgen_test.go
@@ -34,10 +34,10 @@ func TestGeneratePasswordWithLettersAndNumbers(t *testing.T) {
 	pg := passgen.New(opts)
 
 	if password := pg.NewPassword(); !containNumbers(password) {
-		t.Errorf("Expected password to contain NUMBERS, got %q", password)
+		t.Errorf("Expected password to contain numbers, got %q", password)
 	}
 }
 
 func containNumbers(str string) bool {
-	return strings.ContainsAny(str, passgen.NUMBERS)
+	return strings.ContainsAny(str, "0123456789")
 }