pybrady 0.1.3

Python library for Brady label printers (USB, TCP, Bluetooth Classic, BLE)

pybrady

Python 3.10+ library for communicating with Brady label printers.

Status: pre-alpha. Initial target is the Brady BMP51 over USB. The full framework supports USB, TCP (Wi-Fi / Ethernet), Bluetooth Classic SPP, and BLE across Linux, macOS, and Windows, but only the USB + ESC/BMP path is implemented today.

Supported printers (planned)

Model	Protocol	Transports	v0.1
BMP51, BMP53	ESC/BMP	USB, TCP, Bluetooth Classic	USB only
BMP61	ESC/BMP	USB, TCP	—
M610, M710	ESC/BMP	USB, TCP, BLE	—
M611, i5300, S3700, i7500, i4311, C1-30, MJ811	JSON/PICL	USB, TCP, BLE	—
M211, M511, MM100BT	VGL/STX	BLE	—

Install

pip install 'pybrady[usb]'            # USB support (pyusb)
pip install 'pybrady[ble]'            # BLE support (bleak)
pip install 'pybrady[all]'            # everything

Development

pybrady uses uv for environment management, with ruff for lint/format and pytest for tests.

uv sync --all-extras          # create .venv, install package + all optional deps + dev group
uv run pytest                 # run tests
uv run ruff check             # lint
uv run ruff format            # format
uv run mypy src               # type-check

uv.lock is committed — uv sync produces a reproducible environment across machines. The floor Python version is pinned in .python-version; uv will download it automatically if your system Python doesn't match.

Quick start — CLI

brady-print --list-models                         # see supported printers
brady-print --text HELLO --dry-run                # validate bytes, print nothing
brady-print --text HELLO --dry-run --save out.prn # save raw bytes for replay
brady-print --text HELLO                          # actually print to a BMP51

Quick start — Python API

import asyncio
from PIL import Image, ImageDraw, ImageFont
from pybrady import BradyPrinter
from pybrady.transport import UsbTransport

async def main():
    img = Image.new("1", (600, 200), 1)            # 2" x 0.67" @ 300 DPI, white
    draw = ImageDraw.Draw(img)
    draw.text((20, 20), "HELLO", fill=0)            # 0 = black

    async with UsbTransport.find_bmp51() as t:
        printer = BradyPrinter(t, model="BMP51")
        await printer.print(img)

asyncio.run(main())

Permissions (Linux)

The kernel usblp driver claims Brady printers by default. pybrady detaches it automatically at connection time. To avoid running as root:

sudo cp packaging/99-brady.rules /etc/udev/rules.d/
sudo udevadm control --reload
sudo udevadm trigger

Then replug the printer. The rule uses TAG+="uaccess" — systemd-logind grants the active console user ACL access to any Brady USB device, which works out of the box on RHEL/Fedora/Ubuntu/Arch without needing a plugdev or similar group.

License

MPL 2.0. Modifications to pybrady files must be shared back; importing pybrady from proprietary code is fine.

Acknowledgements

Protocol specification based on reverse-engineering of the Brady Express Labels Android app. See /brady_specification.md for the full byte-level spec used to build this library.