Scan a QR code to pair your laptop with an Android phone for wireless debugging. You don't need Android Studio, and you don't have to squint at the phone and type adb pair 10.0.0.5:37755 314159 by hand.

Run it, then on the phone go to Developer options, Wireless debugging, "Pair device with QR code", and scan. adbqr spots the phone over mDNS and does the pairing for you.

Install

brew install kristjan/tap/adbqr

You also need adb, which isn't bundled:

# macOS
brew install --cask android-platform-tools

On Linux, install platform-tools (or android-tools) from your package manager.

Not a Homebrew person? ./install.sh copies the script onto your PATH and leaves adb and qrencode up to you.

Usage

adbqr                 # show the QR, pair when the phone appears
adbqr --timeout 120   # wait longer for the phone
adbqr --help

How the QR renders

adbqr asks the terminal what it can handle and shows the best QR it'll display:

• Terminals with the Kitty graphics protocol (Ghostty, kitty, WezTerm, Konsole) get a real image.
• iTerm2 and WezTerm get one via the iTerm2 image protocol.
• Anything else, including macOS Terminal, VSCode, and piped output, gets a block-character QR from qrencode that scans fine.

It works this out at runtime by querying the terminal, so there's no list of terminal names to keep current.

The public Wi-Fi problem

Pairing depends on mDNS to locate the phone. The QR carries the pairing code but not the phone's address, and that address shows up over mDNS. Lots of public and guest networks run client isolation, which blocks mDNS between devices, so the phone spins forever and nothing pairs.

You can't fix that from the laptop. Use a phone hotspot instead, or go over USB with adb tcpip. adbqr warns you when the network looks like one of these, and again if it's been waiting too long.

What the QR actually contains

Android's pairing format:

WIFI:T:ADB;S:<service-name>;P:<pairing-code>;;

The WIFI: prefix is a red herring. There's no Wi-Fi network involved: S is an mDNS service name rather than an SSID, and P is the pairing code rather than a password. It never reads your SSID and never asks for Location permission.

Hacking on it

The tests want bats-core and zbar (brew install bats-core zbar). They build a QR, decode it again with zbarimg, and confirm the pairing string makes it through, including the Kitty and iTerm2 image renderers.

License

MIT