Build it yourself · Flask + SQLite

Build your first database app.

You'll clone a small guestbook app, run it on your own computer, leave a message that's saved for real, change something, and put it online. Step by step — no experience needed.

Open the repo on GitHub ↗ ← Back to all tutorials
What you're building

A guestbook that remembers

hibot-flask-guestbook is a web app where visitors leave a message and see everyone else's. The new idea here is a database: the messages are saved to a file with SQLite, so they're still there after you close the app or refresh the page. Flask is the small Python framework that ties the web page and the database together.

This is the moment an app stops being a toy and starts remembering things — the core of almost every real product. By the end you'll have it running, saving data, and live online.

Flask SQLite Your first database Open source
Before you start

Three things to have ready

  • Python 3.10 or newerGet it from python.org. To check what you have, open a terminal and type python --version.
  • A terminalThe text window where you type commands. It's called Terminal on Mac/Linux and PowerShell on Windows — both work.
  • A code editor (recommended: Cursor)Any editor opens the files. We like Cursor because its built-in AI can explain each line and help when you get stuck.
The easy-mode way to follow along

Let an AI editor sit beside you

Cursor is a code editor with an AI built in. Open the project in it and you can highlight any line and ask "what does this do?", or describe a change in plain English and watch it edit the file. New builders get 50% off their first month through our link.

Start with Cursor — 50% off →

ⓘ Affiliate disclosure

The walkthrough

From clone to live, one step at a time

  1. Get the code onto your computer

    In your terminal, "clone" the repo — that just means download a copy you can edit. Then step into the new folder.

    # copy the project to your computer git clone https://github.com/Cartooli/hibot-flask-guestbook.git cd hibot-flask-guestbook

    No Git installed? On the repo page, click the green Code button → Download ZIP, then unzip it.

  2. Install what it needs

    The app depends on a few Python packages (Flask among them). This one command installs them all.

    pip install -r requirements.txt

    If pip isn't found, try pip3 or python -m pip instead.

  3. Run it on your own machine

    Start the app. It will keep running and print a web address.

    python app.py

    Open http://localhost:5000 in your browser. Type a message and submit it — then refresh the page. It's still there. That's your database at work.

  4. Look around the files

    Open the folder in your editor. The important pieces:

    app.py — the app: the routes, plus the code that reads from and writes to the database.
    templates/ — the HTML pages Flask fills in with your data.
    sanitize.py — cleans up messages so they're safe to store and show.
    guestbook.db — the SQLite database file, created automatically. This is where messages live.

  5. Make your first change

    Open templates/ and find the page heading. Change the guestbook's title to your own:

    <!-- before --> <h1>Guestbook</h1> <!-- after --> <h1>Alex's Guestbook</h1>

    Save, then refresh http://localhost:5000 — your title is live. (Flask reloads automatically while running.) For a bigger step, look at how app.py saves a message and try adding a second field, like the visitor's city.

  6. Save your work with Git

    Lock in your change. Make your own empty repo on GitHub first, then:

    git add . git commit -m "Make the guestbook mine" git remote set-url origin https://github.com/YOUR-USERNAME/YOUR-REPO.git git push -u origin main

    New to this? Our guide to pull requests walks through saving and publishing work on GitHub.

  7. Put it on the internet

    Because this app keeps a database file on disk, the cleanest home is Railway — it runs always-on Python apps and gives you persistent storage. Connect your GitHub repo, deploy, and you'll get a public address. Want to understand the difference between hosts? Read Vercel vs Railway →

When something breaks

Totally normal — here's the fix

Where to go next

Keep building

Try another starter, or dig into the tools you just used.

Static Site →A web page with HTML, CSS & JS — no build step. FastAPI Starter →Your first backend server, in Python. Streamlit Tool →Build a web app in pure Python. Python CLI →A terminal app with zero dependencies. All EdTech Tutorials →Ten worked example apps to learn from. The AI Build Stack →The full toolkit, tool by tool.

You built a database app. What's next?

Open the live sample, see how it behaves, then keep going. New builders: let Cursor write the next version with you — 50% off your first month through our link.

Get Cursor — 50% off your first month → Open the repo ↗

ⓘ Affiliate disclosure

Disclosure: Some links on this page (Cursor, Railway) are referral or affiliate links — new Cursor users get 50% off their first month, and code.hibot.space may earn a commission at no additional cost to you. This helps keep these guides free. Every other link on this page is a clean URL with no referral code.