diff --git a/cmd.go b/cmd.go
new file mode 100644
index 0000000..1218e6d
--- /dev/null
+++ b/cmd.go
@@ -0,0 +1,46 @@
+package main
+
+import "fmt"
+
+type Cmd struct {
+	Name    string
+	Desc    string
+	Args    []string
+	Aliases []string
+	Fn      func(args []string) error
+}
+
+var CmdList []*Cmd
+
+func init() {
+	CmdList = []*Cmd{
+		CmdVersion,
+		CmdInit,
+	}
+}
+
+func CommandDispatch(args []string) error {
+	var command *Cmd
+	var commandName string
+	var commandArgs = make([]string, 0)
+
+	if len(args) < 2 {
+		commandName = "version"
+	} else {
+		commandName = args[1]
+	}
+
+	for _, cmd := range CmdList {
+		if cmd.Name == commandName {
+			command = cmd
+			break
+		}
+	}
+
+	if command == nil {
+		return fmt.Errorf("Command \"%s\" not found", commandName)
+	}
+
+	err := command.Fn(commandArgs)
+	return err
+}
diff --git a/cmd_init.go b/cmd_init.go
new file mode 100644
index 0000000..b5e0ff1
--- /dev/null
+++ b/cmd_init.go
@@ -0,0 +1,23 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+)
+
+var CmdInit = &Cmd{
+	Name: "init",
+	Fn: func(args []string) error {
+		// check if configuration file already exists.
+		if CheckFileExistence(CONF_FILENAME) {
+			return fmt.Errorf("%s is already exists... ;)", CONF_FILENAME)
+		}
+		// creates new configuration file.
+		err := ioutil.WriteFile(CONF_FILENAME, []byte(INIT_FILE_MESSAGE), 0666)
+		if err != nil {
+			return err
+		}
+		fmt.Println("erk initialized!")
+		return nil
+	},
+}
diff --git a/cmd_version.go b/cmd_version.go
new file mode 100644
index 0000000..1ff686e
--- /dev/null
+++ b/cmd_version.go
@@ -0,0 +1,9 @@
+package main
+
+var CmdVersion = &Cmd{
+	Name: "version",
+	Fn: func(args []string) error {
+		println(VERSION)
+		return nil
+	},
+}
diff --git a/constants.go b/constants.go
new file mode 100644
index 0000000..c56001f
--- /dev/null
+++ b/constants.go
@@ -0,0 +1,8 @@
+package main
+
+const (
+	CONF_FILENAME     = "erkconf.json"
+	INIT_FILE_MESSAGE = `{
+  "write_your_configuration": "here!"
+}`
+)
diff --git a/erk.go b/erk.go
new file mode 100644
index 0000000..d3a4985
--- /dev/null
+++ b/erk.go
@@ -0,0 +1,28 @@
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+func LoadConfig() error {
+	if !CheckFileExistence(CONF_FILENAME) {
+		return fmt.Errorf("Configuration file: %s is not found. please run \"erk init\" first.", CONF_FILENAME)
+	}
+	return nil
+}
+
+func exitIfError(err error) {
+	if err != nil {
+		log_error("error %v", err)
+		os.Exit(1)
+	}
+}
+
+func main() {
+	var args = os.Args
+	// err := LoadConfig()
+	// exitIfError(err)
+	err := CommandDispatch(args)
+	exitIfError(err)
+}
diff --git a/file_existence.go b/file_existence.go
new file mode 100644
index 0000000..548721f
--- /dev/null
+++ b/file_existence.go
@@ -0,0 +1,11 @@
+package main
+
+import "os"
+
+// http://stackoverflow.com/questions/12518876/how-to-check-if-a-file-exists-in-go
+func CheckFileExistence(filename string) bool {
+	if _, err := os.Stat(filename); os.IsNotExist(err) {
+		return false
+	}
+	return true
+}
diff --git a/flag.go b/flag.go
new file mode 100644
index 0000000..1107c57
--- /dev/null
+++ b/flag.go
@@ -0,0 +1,14 @@
+package main
+
+import (
+// "flag"
+// "os"
+)
+
+func SetArgs() {
+
+}
+
+func LoadArgs() {
+	SetArgs()
+}
diff --git a/log.go b/log.go
new file mode 100644
index 0000000..4443ff3
--- /dev/null
+++ b/log.go
@@ -0,0 +1,37 @@
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+const (
+	defaultLogFormat = "erk: %s"
+	errorLogFormat   = "\033[31merk: %s\033[0m"
+)
+
+var logFormat = ""
+
+func formatLog(msg string) string {
+	if logFormat == "" {
+		logFormat = os.Getenv("DIRENV_LOG_FORMAT")
+		if logFormat == "" {
+			logFormat = defaultLogFormat
+		}
+	}
+	return fmt.Sprintf(logFormat, msg)
+}
+
+func log_error(msg string, a ...interface{}) {
+	msg = fmt.Sprintf(errorLogFormat, msg)
+	log(msg, a...)
+}
+
+func log_status(msg string, a ...interface{}) {
+	log(formatLog(msg), a...)
+}
+
+func log(msg string, a ...interface{}) {
+	msg = fmt.Sprintf(msg, a...)
+	fmt.Fprintf(os.Stderr, "%s\n", msg)
+}
diff --git a/version.go b/version.go
new file mode 100644
index 0000000..365e6cb
--- /dev/null
+++ b/version.go
@@ -0,0 +1,3 @@
+package main
+
+const VERSION = "0.0.1"