diff --git a/.github/workflows/python-app.yml b/.github/workflows/python-app.yml
new file mode 100644
index 000000000..a746ede12
--- /dev/null
+++ b/.github/workflows/python-app.yml
@@ -0,0 +1,39 @@
+# This workflow will install Python dependencies, run tests and lint with a single version of Python
+# For more information see: https://docs.github.com/en/actions/automating-builds-and-tests/building-and-testing-python
+
+name: Python application
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Set up Python 3.10
+      uses: actions/setup-python@v3
+      with:
+        python-version: "3.10"
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install flake8 pytest
+        if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+    - name: Lint with flake8
+      run: |
+        # stop the build if there are Python syntax errors or undefined names
+        flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
+        # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
+        flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+    - name: Test with pytest
+      run: |
+        pytest -vv
diff --git a/.gitignore b/.gitignore
index c9863bac6..083db109c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 .venv
-secrets.toml
 __pycache__/
+.DS_Store
+secrets.toml
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index d8afdf641..25c8db679 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -10,4 +10,4 @@ repos:
       hooks:
         - id: black
           language_version: python3.11
-          args: ["--line-length", "100"]
+          args: ["--line-length", "105"]
diff --git a/app_test.py b/app_test.py
new file mode 100644
index 000000000..75cf76570
--- /dev/null
+++ b/app_test.py
@@ -0,0 +1,46 @@
+from unittest.mock import patch
+from streamlit.testing.v1 import AppTest
+from openai.openai_object import OpenAIObject
+
+
+# See https://github.com/openai/openai-python/issues/398
+def create_openai_object_sync(response: str, role: str = "assistant") -> OpenAIObject:
+    obj = OpenAIObject()
+    message = OpenAIObject()
+    content = OpenAIObject()
+    content.content = response
+    content.role = role
+    message.message = content
+    obj.choices = [message]
+    return obj
+
+
+@patch("openai.ChatCompletion.create")
+def test_Chatbot(openai_create):
+    at = AppTest.from_file("Chatbot.py").run()
+    assert not at.exception
+    at.chat_input[0].set_value("Do you know any jokes?").run()
+    assert at.info[0].value == "Please add your OpenAI API key to continue."
+
+    JOKE = "Why did the chicken cross the road? To get to the other side."
+    openai_create.return_value = create_openai_object_sync(JOKE)
+    at.text_input(key="chatbot_api_key").set_value("sk-...")
+    at.chat_input[0].set_value("Do you know any jokes?").run()
+    print(at)
+    assert at.chat_message[1].markdown[0].value == "Do you know any jokes?"
+    assert at.chat_message[2].markdown[0].value == JOKE
+    assert at.chat_message[2].avatar == "assistant"
+    assert not at.exception
+
+
+@patch("langchain.llms.OpenAI.__call__")
+def test_Langchain_Quickstart(langchain_llm):
+    at = AppTest.from_file("pages/3_Langchain_Quickstart.py").run()
+    assert at.info[0].value == "Please add your OpenAI API key to continue."
+
+    RESPONSE = "1. The best way to learn how to code is by practicing..."
+    langchain_llm.return_value = RESPONSE
+    at.sidebar.text_input[0].set_value("sk-...")
+    at.button[0].set_value(True).run()
+    print(at)
+    assert at.info[0].value == RESPONSE
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 872abf3b2..8635be6db 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -2,3 +2,4 @@ black==23.3.0
 mypy==1.4.1
 pre-commit==3.3.3
 watchdog
+pytest
diff --git a/requirements.txt b/requirements.txt
index c2737f628..9b90305d8 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-streamlit>=1.26.0
+streamlit>=1.28
 langchain>=0.0.217
 openai
 duckduckgo-search