diff --git a/src/nlp4ss/__cli__.py b/src/nlp4ss/__cli__.py
new file mode 100644
index 0000000..b62c0ac
--- /dev/null
+++ b/src/nlp4ss/__cli__.py
@@ -0,0 +1,69 @@
+"""Command line interface for nlp4ss"""
+
+# Importing the libraries
+import os
+import subprocess
+import webbrowser
+
+import click
+import yaml
+
+from nlp4ss._version import __version__
+
+__package_path__ = os.path.abspath(os.path.dirname(__file__))
+__package_name__ = os.path.basename(__package_path__)
+
+
+def load_about() -> dict:
+    """
+    Load the about.yml file.
+    """
+
+    about_path = os.path.join(__package_path__, f"conf/about/{__package_name__}.yaml")
+    if not os.path.isfile(about_path):
+        click.echo(f"The `{about_path}` was not found.")
+        raise click.Abort()
+    with open(about_path, "r", encoding="utf-8") as f:
+        return yaml.load(f, Loader=yaml.Loader)
+
+
+__about__ = load_about()
+
+
+@click.command()
+@click.version_option(__version__)
+@click.option("--build", "-b", is_flag=True, help="Build the book")
+def main(build: bool = False) -> None:
+    """
+    This is the cli function of the package.
+    It opens the book in the browser or builds the book.
+    """
+    if build:
+        click.echo("Building the book...")
+        build_book()
+    else:
+        open_book()
+
+
+def open_book() -> None:
+    """
+    Open the book in the browser.
+    """
+    click.echo("Opening the book...")
+    webbrowser.open_new_tab(__about__["homepage"])
+
+
+def build_book() -> None:
+    """
+    Build the book.
+    """
+    book_path = os.path.join(__package_path__, "book")
+    if not os.path.isdir(book_path):
+        click.echo("The book directory was not found.")
+        return
+    subprocess.run(["jupyter-book", "build", book_path], check=True)
+
+
+# main function for the main module
+if __name__ == "__main__":
+    main()
diff --git a/src/nlp4ss/__init__.py b/src/nlp4ss/__init__.py
new file mode 100644
index 0000000..27d5e3b
--- /dev/null
+++ b/src/nlp4ss/__init__.py
@@ -0,0 +1,13 @@
+from nlp4ss._version import __version__
+
+
+def get_version() -> str:
+    """
+    Get the version of the package. This is the cli function of the package.
+    If you want to check the version of the package you can use this function.
+
+
+    Returns:
+        The version of the package as a string e.g. "0.1.0"
+    """
+    return __version__
diff --git a/src/nlp4ss/_version.py b/src/nlp4ss/_version.py
new file mode 100644
index 0000000..6c8e6b9
--- /dev/null
+++ b/src/nlp4ss/_version.py
@@ -0,0 +1 @@
+__version__ = "0.0.0"
diff --git a/src/nlp4ss/conf/about/nlp4ss.yaml b/src/nlp4ss/conf/about/nlp4ss.yaml
new file mode 100644
index 0000000..f6e408d
--- /dev/null
+++ b/src/nlp4ss/conf/about/nlp4ss.yaml
@@ -0,0 +1,6 @@
+_open_link_: True
+name: "NLP for Social Science"
+authors: "Young Joon Lee <entelecheia@hotmail.com>"
+description: "A course on applying natural language processing (NLP) techniques for social science research."
+homepage: "https://nlp4ss.entelecheia.ai"
+license: "CC-BY-4.0"
diff --git a/src/nlp4ss/py.typed b/src/nlp4ss/py.typed
new file mode 100644
index 0000000..e69de29
diff --git a/tests/nlp4ss/test_cli.py b/tests/nlp4ss/test_cli.py
new file mode 100644
index 0000000..24d9be2
--- /dev/null
+++ b/tests/nlp4ss/test_cli.py
@@ -0,0 +1,22 @@
+"""
+test cli module
+"""
+import subprocess
+from typing import List, Tuple
+
+
+def capture(command: List[str]) -> Tuple[bytes, bytes, int]:
+    proc = subprocess.Popen(
+        command,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+    )
+    out, err = proc.communicate()
+    return out, err, proc.returncode
+
+
+def test_cli() -> None:
+    """Test cli module"""
+    command = ["nlp4ss"]
+    out, err, exitcode = capture(command)
+    assert exitcode == 0
diff --git a/tests/nlp4ss/test_init.py b/tests/nlp4ss/test_init.py
new file mode 100644
index 0000000..ec5cf8a
--- /dev/null
+++ b/tests/nlp4ss/test_init.py
@@ -0,0 +1,12 @@
+from nlp4ss import get_version
+
+
+def test_get_version() -> None:
+    """
+    Test the get_version function.
+
+    version format: major.minor.patch[.devN+g<git hash>]
+    """
+    version = get_version()
+    # check version format
+    assert version.count(".") in range(2, 5)