diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..41bbbc7
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "buildrs"
+version = "0.1.0"
+authors = ["Hatter Jiang <jht5945@gmail.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+clap = "2.33.1"
diff --git a/src/cmd.rs b/src/cmd.rs
new file mode 100644
index 0000000..7b40197
--- /dev/null
+++ b/src/cmd.rs
@@ -0,0 +1,12 @@
+use clap::{ ArgMatches, App, };
+
+pub type CommandError = Result<(), Box<dyn std::error::Error>>;
+
+pub trait Command {
+
+    fn subcommand<'a>(&self) -> App<'a, 'a>;
+
+    fn name(&self) -> &str;
+
+    fn run(&self, arg_matches: &ArgMatches, _: &ArgMatches) -> CommandError;
+}
diff --git a/src/cmd_default.rs b/src/cmd_default.rs
new file mode 100644
index 0000000..fd5c96f
--- /dev/null
+++ b/src/cmd_default.rs
@@ -0,0 +1,23 @@
+use clap::{ App, Arg, ArgMatches, };
+use crate::cmd::CommandError;
+
+pub struct CommandDefault;
+
+impl CommandDefault {
+
+    pub fn process_command<'a>(app: App<'a, 'a>) -> App<'a, 'a> {
+        app.arg(Arg::with_name("verbose")
+                    .long("verbose")
+                    .short("v")
+                    .multiple(true)
+                    .help("Show verbose info")
+        )
+    }
+
+    pub fn run(arg_matches: &ArgMatches) -> CommandError {
+        let verbose_count = arg_matches.occurrences_of("verbose");
+        println!("Verbose count: {}", verbose_count);
+        // TODO ...
+        Ok(())
+    }
+}
\ No newline at end of file
diff --git a/src/cmd_sample.rs b/src/cmd_sample.rs
new file mode 100644
index 0000000..b1bd812
--- /dev/null
+++ b/src/cmd_sample.rs
@@ -0,0 +1,20 @@
+use clap::{ ArgMatches, SubCommand, App, };
+use crate::cmd::{ Command, CommandError, };
+
+pub struct CommandSample;
+
+impl Command for CommandSample {
+
+    fn subcommand<'a>(&self) -> App<'a, 'a> {
+        SubCommand::with_name(self.name()).about("Sample subcommand")
+    }
+
+    fn name(&self) -> &str {
+        "sample"
+    }
+
+    fn run(&self, _arg_matches: &ArgMatches, _sub_arg_matches: &ArgMatches) -> CommandError {
+        println!("This is test command!");
+        Ok(())
+    }
+}
diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..ec50fe9
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,31 @@
+use clap::App;
+
+mod cmd;
+mod cmd_sample;
+mod cmd_default;
+
+use cmd::{ Command, CommandError, };
+use cmd_sample::CommandSample;
+use cmd_default::CommandDefault;
+
+fn main() -> CommandError {
+    let commands = vec![
+        CommandSample{},    
+    ];
+    let mut app = App::new(env!("CARGO_PKG_NAME"))
+                    .version(env!("CARGO_PKG_VERSION"))
+                    .about(env!("CARGO_PKG_DESCRIPTION"));
+    app = CommandDefault::process_command(app);
+    for command in &commands {
+        app = app.subcommand(command.subcommand());
+    }
+
+    let matches = app.get_matches();
+    for command in &commands {
+        if let Some(sub_cmd_matches) = matches.subcommand_matches(command.name()) {
+            return command.run(&matches, sub_cmd_matches);
+        }
+    }
+
+    CommandDefault::run(&matches)
+}