diff --git a/.DS_Store b/.DS_Store
index dd5f517..fcd4247 100644
Binary files a/.DS_Store and b/.DS_Store differ
diff --git a/src/openenergyid/__init__.py b/openenergyid/__init__.py
similarity index 100%
rename from src/openenergyid/__init__.py
rename to openenergyid/__init__.py
diff --git a/src/openenergyid/main.py b/openenergyid/main.py
similarity index 58%
rename from src/openenergyid/main.py
rename to openenergyid/main.py
index 202ba75..d3e5d79 100644
--- a/src/openenergyid/main.py
+++ b/openenergyid/main.py
@@ -1,2 +1,6 @@
-if __name__ == '__main__':
+def main():
     print('Hello World!')
+    return 0
+
+if __name__ == '__main__':
+    main()
diff --git a/pyproject.toml b/pyproject.toml
index dbf4425..fd74e16 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -31,4 +31,7 @@ classifiers = [
 ]
 
 [project.urls]
-homepage = "www.energyid.eu"
\ No newline at end of file
+homepage = "www.energyid.eu"
+
+[tool.hatch.version]
+path = "openenergyid/__init__.py"
\ No newline at end of file
diff --git a/src/.DS_Store b/src/.DS_Store
deleted file mode 100644
index 4c5d51c..0000000
Binary files a/src/.DS_Store and /dev/null differ
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/test_main.py b/tests/test_main.py
new file mode 100644
index 0000000..d37482d
--- /dev/null
+++ b/tests/test_main.py
@@ -0,0 +1,8 @@
+from openenergyid import __version__
+from openenergyid.main import main
+
+def test_version():
+    assert __version__ == '0.0.1'
+
+def test_main():
+    assert main() == 0