diff --git a/.github/workflows/flake8.yml b/.github/workflows/flake8.yml
new file mode 100644
index 0000000..a8d203f
--- /dev/null
+++ b/.github/workflows/flake8.yml
@@ -0,0 +1,25 @@
+# https://github.com/marketplace/actions/run-flake8-with-reviewdog
+
+name: flake8 Lint
+
+on: [push, pull_request]
+
+jobs:
+  flake8-lint:
+    runs-on: ubuntu-latest
+    name: flake8 Lint
+    steps:
+      - name: Check out source repository
+        uses: actions/checkout@v4
+      - name: Set up Python environment
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+      # Install specific flake8 version (this step is not required. Default is "latest").
+      - run: pip install flake8==6.0.0
+      # Install flake8 extensions (this step is not required. Default is "None").
+      - run: pip install flake8-docstrings flake8-simplify flake8-unused-arguments flake8-quotes
+      - name: flake8 Lint
+        uses: reviewdog/action-flake8@v3
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
diff --git a/__pycache__/subtotxt.cpython-310-pytest-8.3.2.pyc b/__pycache__/subtotxt.cpython-310-pytest-8.3.2.pyc
new file mode 100644
index 0000000..5205006
Binary files /dev/null and b/__pycache__/subtotxt.cpython-310-pytest-8.3.2.pyc differ
diff --git a/pyproject.toml b/pyproject.toml
index 23650bc..1a7ad54 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -21,4 +21,11 @@ exclude = '''
   | venv
   | test/resources
 )/
-'''
\ No newline at end of file
+'''
+
+[tool.pytest.ini_options]
+minversion = "6.0"
+addopts = "-ra -q"
+testpaths = [
+    "tests"
+]
\ No newline at end of file
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/tests/__init__.py
@@ -0,0 +1 @@
+