qrx

Interactive QR code toolkit. Create plain or encrypted QR codes (text, URL, WiFi, vCard, phone, SMS, email, location, calendar event), save them as .png/.jpg, and read them back — all through a simple terminal menu, no flags or arguments to memorize.

Installation

pip install qrx

or clone this repo and:

pip install -e .

Usage

qrx

or, without installing:

python run.py

or from your own Python code:

from qrx import qr
qr.run()

All three do exactly the same thing — they launch the same interactive menu. Use whichever fits how you're working: a terminal command, a local script, or a single import inside another program.

You'll see:

1) Create QR code
2) Create encrypted QR code (readable only via qrx)
3) Read QR code

1) Create QR code

Asks which type of QR you want:

1) Plain text
2) URL
3) WiFi
4) vCard (contact)
5) Phone number
6) SMS
7) Email
8) Location (geo)
9) Calendar event

Each type asks exactly the fields it needs — pick WiFi and it asks for network name/password/security type; pick vCard and it asks for name/phone/email/organization/title, and so on. You never type a raw QR payload format yourself; qrx builds the correct standard string (WIFI:..., mailto:..., tel:..., smsto:..., geo:..., vCard, iCalendar) for you.

At the end, you're asked for an output filename (.png or .jpg), and the QR code image is saved there.

2) Create encrypted QR code

Exactly the same flow as option 1 (pick a type, answer its questions), but at the end you also set a password. The content is encrypted before being placed into the QR code.

Important: the QR code you get is a completely normal, standard QR code — any phone camera can scan it. But scanning it with a regular camera app just shows unreadable encrypted text. Only qrx (with the correct password) can turn it back into the real content.

3) Read QR code

Asks for the path to a QR code image (.png/.jpg/.jpeg).

• If it's a normal QR code, the decoded content is shown directly.
• If it's a qrx-encrypted QR code, you're asked for the password. Correct password → the real content is shown. Wrong password → you're told it's wrong, nothing is revealed.

Why passwords, not links

A QR code can only hold a few kilobytes of data — nowhere near enough for a real image/photo. So qrx sticks to text-based payloads (the 9 types above), which is also what makes it work completely offline: no server, no internet connection needed to generate or read a qrx QR code (unless the QR itself encodes a URL that points somewhere — the QR always scans fine, but whether the destination page loads depends on that server being up, same as any URL).

Programmatic usage (advanced)

If you want to launch the whole interactive menu from your own code (same as running qrx from the terminal):

from qrx import qr
qr.run()

Or, if you want to skip the interactive menu entirely and call things directly:

from qrx import formats, qr, crypto

# build a payload
payload = formats.build_wifi("MyNetwork", "mypassword", security="WPA")

# generate a QR image from it
qr.generate_qr_image(payload, "wifi.png")

# read it back
decoded = qr.read_qr_image("wifi.png")

# encrypt/decrypt payloads directly
encrypted = crypto.encrypt_payload("secret message", "mypassword")
crypto.is_encrypted(encrypted)  # True
original = crypto.decrypt_payload(encrypted, "mypassword")

Available builders in qrx.formats:

How the encryption works

qrx uses Fernet (AES-128-CBC with HMAC authentication) from the cryptography library. The password is turned into an encryption key using PBKDF2-HMAC-SHA256 with a random 16-byte salt and 390,000 iterations, so the same password produces a different encrypted result every time, and brute-forcing the password is expensive.

The encrypted payload embedded in the QR code looks like:

QRX-ENC-V1:<base64 salt>.<fernet token>

The QRX-ENC-V1: prefix is how qrx recognizes its own encrypted QR codes when reading one back — it's not a secret, just a marker.

Notes

• QR reading is done with OpenCV's built-in QRCodeDetector — no external system libraries (like libzbar) are required, so installation is clean and consistent across Windows, Mac, and Linux with a plain pip install qrx.
• QR error correction is set to level M (up to ~15% of the code can be damaged/obscured and still scan correctly).
• If multiple QR codes exist in one image, only the first one found is read.
• This is a local, offline tool — nothing is sent anywhere. Your data and passwords never leave your machine.