opcua-client

Simple OPC-UA GUI client built on asyncua and PyQt6.

PRs welcome for any wished improvements.

Features

• Connect / disconnect, with automatic reconnect when the transport drops: views grey out and a status-bar banner is shown while the supervisor re-establishes the session.
• Browse the address space with per-node-type icons.
• Show attributes and references for the selected node.
• Subscribe to variable data changes and to events.
• Write variable values.
• GUI for application certificates and per-server security mode / policy.
• Call methods (with dialog).
• Live-plot subscribed variables (pyqtgraph).
• Persist connection history, the last-browsed node per server, and window layout via QSettings.
• Context menu with handy helpers: copy NodeId, or copy the full browse path so you can paste it into your own code: client.nodes.root.get_child(['0:Objects', '2:MyNode']).

Install

PyQt6 is required. Python 3.14 or newer.

pip install opcua-client
opcua-client

pip install opcua-client --upgrade to update.

Development

The project uses uv for environment and build management.

uv sync             # install deps + dev tools into .venv
uv run python app.py
uv run python tests.py           # integration tests need a free port
uv run mypy uaclient uawidgets   # type check

After editing any .ui or .qrc source, run make to regenerate uaclient/*_ui.py, uaclient/theme/breeze_resources.py, and uawidgets/resources.py. Targets:

• make — regenerate UI / resource Python from Qt sources.
• make run — launch the GUI.
• make edit — open the main .ui in Qt Creator.

Cutting a release:

uv run python release.py    # bumps pyproject.toml, tags, uv build, uv publish

asyncua is currently consumed via a local path source ([tool.uv.sources] asyncua = { path = "../opcua-asyncio", editable = true }) because the 2.x line is still in pre-release. Drop the source entry once asyncua>=2.0 is on PyPI.

TODO

• History read.