Desktop app to print labels on a NIIMBOT B1 over USB serial. Optional logging records each successful print.

The app can also integrate with Pretix to check-in and print badges, see the section below.

TLDR Downloads: GitHub Releases include two GNU/Linux AppImage builds: NIIMBOT-Printer-<version>-<arch>.AppImage (standalone, no Pretix support) and NIIMBOT-Printer-<version>-<arch>-pretix.AppImage (with Pretix support).

Requirements

• Python 3.10+
• System packages often needed for wxPython wheels: GTK3, etc. (on Ubuntu: python3-pip and a desktop environment usually pull these in).
• USB serial access: user must be able to read/write the device (e.g. dialout group on GNU/Linux).

sudo usermod -aG dialout "$USER"
# then log out and back in

Run from source

cd /path/to/niimbot-printer
python3 -m venv .venv
source .venv/bin/activate
pip install -e .
python -m niimbot_printer
# or: niimbot-printer

Configuration is stored under XDG paths:

• ~/.config/niimbot-printer/config.json
• ~/.local/share/niimbot-printer/state.json (next sequence number)
• When logging is enabled, the audit file is always ~/print.log (JSON Lines). The file is created automatically on first logged print.

If you used an older build, config may have lived under ~/.config/niimbot-welcome/; copy or re-enter settings as needed.

Bundled font

The default typeface is Bitter (Latin Ext 600), bundled under src/niimbot_printer/data/fonts/.
Copyright (c) 2011-2020, Sol Matas (www.solmatas.com) Licensed under the SIL Open Font License, Version 1.1 — see src/niimbot_printer/data/fonts/OFL.txt.

You can override it in Settings with any TTF/OTF path.

Log format (JSONL)

Each line is one JSON object, for example:

{"ts":"2026-04-18T14:30:00Z","name":"Ada Lovelace","seq":12,"source":"manual","pretix_event_slug":null,"pretix_order_code":null,"pretix_position_id":null,"label_copies":2}

The name field holds the printed text line. Logging is on by default; disable it in File → Settings if you do not want content written to disk.

Successful Pretix prints set source to "pretix" and fill pretix_event_slug, pretix_order_code, and pretix_position_id when Pretix returns them.

Pretix check-in (optional)

The app can call your Pretix instance’s check-in redeem API, check in a ticket from the scanned secret, then print a name badge. This is off by default and does not contact the network until you enable it in Settings.

1. In Pretix (organizer settings), create an API token with permission to manage check-ins for your events.
2. In File → Settings, under Pretix (optional):
   • Enable Pretix check-in and badge printing.
   • Pretix base URL — HTTPS only, e.g. https://kayit.oyd.org.tr (no trailing slash). If Pretix lives under a subpath, include it (e.g. https://host/pretix).
   • Organizer slug — as in https://…/org/<slug>/.
   • API token — or leave empty and set environment variable PRETIX_API_TOKEN or PRETX_TOKEN (env wins over the saved field).
   • Event slug — used only by Load lists to query check-in lists.
   • Check-in list ID(s) — comma-separated integers for the list(s) you scan against (use Load lists or copy IDs from Pretix admin).
   • Badge text template — Python str.format placeholders: {attendee_name}, {company}, {order}, {item}. Use a real newline in the field, or the two characters \n for a line break.
   • Show and verify each Pretix label before printing — after a successful check-in, a dialog shows the resolved text read-only; Enter confirms and prints (or use Print label). Edit text unlocks the field so you can fix typos before printing. Cancel skips printing (check-in already recorded in Pretix).

QR / barcode: USB scanners in keyboard mode usually type the ticket secret into the Ticket secret field; press Enter or click Check in and print label. Camera-based decoding is not included in the default build.

“Load lists” returns HTTP 404 with an HTML “Not found” page: Your Pretix server is almost certainly fine — that response is what the obsolete API path /organizers/…/checkinlists/?event=… returns. Update this app and reinstall (pip install -e . from the current tree) or use a freshly built full AppImage. The correct path is /api/v1/organizers/{org}/events/{event}/checkinlists/ (see check-in lists API).

Standalone / minimal build: packaging/pyinstaller-minimal.spec excludes the Pretix package so the frozen app stays smaller; the Pretix panel is hidden and the status line notes that Pretix is unavailable. Use the main packaging/pyinstaller.spec (or the full AppImage from releases) for Pretix support.

Packaging (PyInstaller + AppImage)

Build a windowed binary folder with PyInstaller:

pip install -e ".[dev]"
pyinstaller packaging/pyinstaller.spec

The runnable is dist/niimbot-printer/niimbot-printer. The spec bundles the data/fonts directory for the default Bitter font and includes Pretix integration.

For a smaller bundle without Pretix:

pyinstaller packaging/pyinstaller-minimal.spec
# runnable: dist/niimbot-printer-minimal/niimbot-printer

Wrap a bundle as an AppImage (install appimagetool first). Use a plain filename for the minimal bundle and APPIMAGE_VARIANT=pretix for the full bundle so local builds match release names:

chmod +x packaging/build-appimage.sh
# After pyinstaller packaging/pyinstaller-minimal.spec:
DIST_NAME=niimbot-printer-minimal ./packaging/build-appimage.sh
# After pyinstaller packaging/pyinstaller.spec:
APPIMAGE_VARIANT=pretix ./packaging/build-appimage.sh

This produces dist/NIIMBOT-Printer-<version>-<arch>.AppImage (standalone) and dist/NIIMBOT-Printer-<version>-<arch>-pretix.AppImage (with Pretix), or leaves a ready-to-use build/AppDir if appimagetool is not installed.

Release CI builds both AppImages when you push a version tag.

For widest GNU/Linux compatibility, build on the oldest distro you intend to support (glibc on the build machine sets the floor).

Settings

• Serial port — e.g. /dev/ttyACM0 (refresh lists USB serial devices when available).
• Font file — optional; empty uses bundled Bitter. Bold prefers a *-Bold.ttf next to the chosen file or common system bold fonts.
• Label width / height — default 384×240 pixels (width must be a multiple of 8).
• Density / label type — match niimctl defaults (3 and 1); adjust if your media requires it.
• Labels per print — how many identical labels to feed per print action (manual or Pretix); default 1. Jobs are sent in one USB serial session, with a short pause after the last job before closing USB, so every copy completes (closing the port immediately after the last command often drops the final label).
• Logging — toggle only; path is always ~/print.log when enabled.
• Pretix — optional; see Pretix check-in (optional). The API token is stored in config.json; restrict file permissions on shared machines or prefer env vars.

Thanks

• hairymnstr/niimctl for protocol reverse engineering

License

Copyright (C) 2026 Özcan Oğuz

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see https://www.gnu.org/licenses/.