What you’ll learn

• What the finished AI app looks like and what it can do
• How this course is organized into four parts
• How each lesson works, from slides to the quiz
• How to set up your course folder and check that your computer is ready

What you’ll build

By the end of this course you’ll have your own AI assistant app. You choose what it does: a study buddy, a recipe helper, a writing coach, or your own idea. Your finished app will:

• Talk to a real AI model (OpenAI or Anthropic Claude)
• Have its own personality and rules that you write
• Remember the conversation, so you can ask follow-up questions
• Save chats to a file and load them next time
• Run in a web browser with a simple chat screen
• Handle problems like a bad internet connection without crashing

How the course is organized

• Part 1: How AI Apps Work. You’ll learn what an API is, get an API key, keep it safe, and make your first call to an AI.
• Part 2: Talking to AI with Python. You’ll write better prompts, build a chat loop that remembers, and handle errors.
• Part 3: Adding Anthropic Claude. You’ll connect a second AI provider and write one function that works with both.
• Part 4: Build and Share Your AI App. You’ll plan your app, add a web screen, test it, and share it online.

How each lesson works

Every lesson follows the same pattern, just like in Python for Absolute Beginners:

1. Read the lesson text and watch the narrated slides.
2. Play with the Try it widget right on the page.
3. Do the hands-on exercise with the practice file.
4. Check yourself with the “You’re done when…” line.
5. Take the short quiz. You’ll see the correct answers after you submit.
6. Click through to the next lesson.

What AI costs

AI providers charge a tiny amount each time your program sends a message. For this whole course, most students spend only a few dollars. In Part 1 you’ll set a spending limit, so you can never be surprised by a bill. You don’t need to pay for anything in this lesson.

Get your computer ready

You already installed Python and VS Code in Python for Absolute Beginners. Now you’ll make a home for this course:

1. Create a new folder called ai-app-course (in Documents or on your Desktop).
2. Download setup_check.py and assistant_preview.py from this lesson and move them into that folder.
3. Open the folder in VS Code (File > Open Folder).
4. Open a terminal in VS Code (Terminal > New Terminal). It opens inside your folder.

Example: running a Python file

In the terminal, type this and press Enter:

python setup_check.py

On Mac or Linux, if that doesn’t work, use:

python3 setup_check.py

Common mistakes

• Running the file from the wrong folder. If the terminal says “No such file or directory,” you’re not in ai-app-course. Open the folder in VS Code first, then open a new terminal.
• Typing python when your computer needs python3. On Mac and Linux, try python3 if python isn’t found.
• Forgetting to save. If your changes don’t show up, save the file (Ctrl+S or Cmd+S) and run it again.
• Using curly quotes. If you copy code from a word processor, “smart” quotes break Python. Always type straight quotes in VS Code.
• Worrying about the AI part already. This lesson has no real AI yet. That starts in Part 1.

Pick a personality for your future app and send it a message. Then click “Show the Python behind this.” Watch how each message you send is added to a list. That list is how your app will remember the conversation.

Hands-on exercise

1. Create your ai-app-course folder and put both practice files in it.
2. Open setup_check.py in VS Code.
3. Change MY_NAME to your name and MY_APP_IDEA to one sentence describing the AI app you’d like to build.
4. Save the file and run it with python setup_check.py.
5. Fix any PROBLEM lines and run it again until every check passes.
6. Bonus: run python assistant_preview.py, say hi, send a few messages, then type quit.

Practice files

• Download the Lesson 1 practice files (ZIP): setup_check.py and assistant_preview.py
• setup_check.py checks your Python version (3.10 or newer), that pip is installed, that you’re running from the ai-app-course folder, and that you filled in your name and app idea.
• assistant_preview.py is a pretend chat app with a while loop, input(), and a list that stores the conversation. It has no real AI yet. In Part 1 you’ll replace its pretend brain with a real model.

You’re done when: setup_check.py prints “4 of 4 checks passed.” and the last line says “Ready to build, <your name>!” Example of a finished run:

Python version: 3.13
  OK - your Python is new enough.
pip (the package installer): found
  OK - you'll use pip in Part 1 to install the AI packages.
Current folder: ai-app-course
  OK - you're running this from your course folder.
Your app idea: A study buddy that quizzes me on history
  OK - keep this idea in mind. You'll build it in Part 4.

4 of 4 checks passed.
Ready to build, Maria!

Key takeaways

• You’ll build a browser-based AI assistant with its own personality, memory and saved chats.
• The course has four parts: how AI apps work, chatting with OpenAI, adding Claude, and building and sharing your app.
• Every lesson ends with a “You’re done when…” check and a short quiz.
• AI costs only a few dollars for the whole course, and you’ll set a spending limit in Part 1.
• Your course folder is ai-app-course, and every practice file goes there.

Watch the video lesson