Append HMI Desktop

Append HMI Desktop runs HMI applications (.ahmi projects) made with Append HMI Studio on operator PCs. It's the Studio's runtime without the editor: nothing can be edited, saved, exported or published, which makes it smaller and simpler to deploy.

• Run from the command line: append-hmi-desktop project.ahmi runs a project.
• Run from the launcher: with no project, a window opens where you pick an .ahmi file, then:
  • Run now;
  • create a desktop shortcut or a Start menu / applications menu entry that runs it;
  • tick Run automatically when I log in.
• Each project runs as its author set it up in Studio (HMI > Application Settings):
  • kiosk, full screen or a window at the project's resolution;
  • exit with Ctrl+Alt+Shift+Q, by closing the window as any program's (its close button or Alt+F4), with Ctrl+Alt+Shift+Q and a password, or not at all.
• Several projects at once, one window each (for example one per monitor). Starting a project that is already running brings its window forward.
• Everything the Studio's Run does comes with it:
  • live PLC data through the bundled hmi-comms server (EtherNet/IP ControlLogix/CompactLogix, SLC 5/05 and MicroLogix, Modbus TCP, simulator);
  • alarms with daily CSV history;
  • retentive tags;
  • users and access levels;
  • recipes, with CSV export and import;
  • trends, with 7 days of history;
  • list boxes the operator picks from, filled by the List* script functions;
  • the date and time: the clock system tags, Now(format) and _Now in the format _TimeFormat holds;
  • popup windows the operator moves by dragging their title bar, drawn in the height, font and colors the project sets;
  • the project's touch background color, which every object with a touch animation is drawn in while the operator holds it down;
  • databases: the SQL* script functions against Microsoft SQL Server and SQLite, with the data sources the project carries.
  • Each project keeps its own alarm and trend history, retentive values, runtime user changes, saved recipes and database credentials.

Command line

append-hmi-desktop [options] [project.ahmi]

  --create-shortcut <where>  Create a shortcut that runs the project, then exit
                             (<where>: desktop or menu).
  --startup <on|off>         Run the project when the user logs in, or stop, then exit.
  --disable-acceleration     Turn off GPU acceleration.
  -h, --help                 Show help.
  -v, --version              Show the version.

• Exit codes: 0 on success, 1 when the project can't be used, 2 for a usage error.
• Windows executable: C:\Program Files\Append HMI Desktop\Append HMI Desktop.exe.

Shortcuts and startup entries are per user and need no administrator rights:

	Windows	Linux
Desktop shortcut	Desktop\<project>.lnk	~/Desktop/append-hmi-desktop-<project>-<id>.desktop
Menu entry	Start menu > Programs > Append HMI Desktop	~/.local/share/applications/
Run at login	Start Menu\Programs\Startup\<project>.lnk	~/.config/autostart/

Opening .ahmi files

• Windows installer:
  • adds Run with Append HMI Desktop to the right-click menu of every .ahmi file;
  • makes double-click run the project only when nothing else opens .ahmi files. With Append HMI Studio installed, double-click still opens the project in the Studio for editing.
• Linux packages: Append HMI Desktop is offered under Open With for .ahmi files.

Download

Releases are published at github.com/AppendAutomation/AppendHMIDesktop/releases:

• Append-HMI-Desktop-<version>-Setup.exe
  • Windows 10/11 x64, for all users.
  • Silent install: /S. Silent uninstall: "C:\Program Files\Append HMI Desktop\Uninstall.exe" /S.
• Append-HMI-Desktop-<version>-x86_64.AppImage: Linux, runs without installing.
• Append-HMI-Desktop-<version>-amd64.deb: Debian and Ubuntu.

The installers are not code-signed yet, so Windows SmartScreen asks for confirmation on first run.

Settings, logs and project data are kept in:

• %APPDATA%\Append HMI Desktop on Windows;
• ~/.config/Append HMI Desktop on Linux.

The log is logs/main.log. Inside that folder each project has its alarm history (alarms/), trend history (trends/), retentive values (retentive/), runtime users (users/), saved recipes (recipes/) and the credentials this PC holds for its data sources (datasources/). A project whose data source is a SQLite file keeps it in databases/ there, or in the user's Documents folder, whichever the data source names — the same two places Append HMI Studio uses. See HMI_SQL.md.

Desktop or Publish?

Append HMI Studio's HMI > Publish builds a Windows installer for one project, with its own name and icon, that starts straight into that project. Append HMI Desktop is installed once and runs any project file you give it. Use Publish for a locked-down, single-purpose station; use Desktop when projects are copied around or change often, or on Linux.

What's left out

Append HMI Desktop reuses Append HMI Studio's run-only renderer, comms server and data stores unchanged, from the studio/ submodule. Everything only the editor needs is left out:

• Web app: 46 MB of the editor's 156 MB (app.asar 40 MB instead of 106 MB).
  • Out: the unminified editor sources, stencil XML, templates, the viewer and embed bundles, translations and source maps.
  • In: the image libraries a project's images may use.
• Studio's main process: replaced by a small one.
  • Out: file editing, drafts, PDF/SVG export, the Publish template and NSIS, the automation CLI, the settings and context-menu libraries.
  • The runtime dependencies are electron-log and tedious, the SQL Server driver the SQL* script functions need (SQLite is Node's own node:sqlite). Its Azure AD packages, 56 MB of it, are replaced by stubs: Azure authentication is not an option a data source offers.
• Chromium translations: English only.

Result: installers of about 130 MB instead of 166 MB (Windows), and a 150 MB AppImage instead of 348 MB. Most of what remains is Electron itself.

Building

With Node.js 22.12+ and the .NET 8 SDK:

git clone --recursive https://github.com/AppendAutomation/AppendHMIDesktop.git
cd AppendHMIDesktop
npm install
npm run build-comms       # the hmi-comms server, into studio/comms/publish/
npm start                 # the launcher; npm start -- path/to/project.ahmi runs one
npm test
npm run dist-win          # Windows installer (on Linux too, no wine)
npm run dist-linux        # AppImage and deb

• Dev tools: HMI_ENV=dev npm start opens DevTools.
• Updating the Studio: move the studio submodule to a newer AppendHMIStudio commit to pick up runtime changes, then rebuild: git -C studio pull && git submodule update --init --recursive.

Path	Contents
src/main/	Main process: command line, launcher and project windows, shortcuts, the runtime's IPC
src/launcher/	The launcher window (plain HTML, no editor code)
studio/	Submodule: AppendHMIStudio, with its drawio fork and comms server
scripts/	Build scripts: installers, NSIS download, icons
build/	Icons and the Electron fuses hook
src/test/	Unit tests (npm test)

License and attribution

Append HMI Desktop is © 2026 Append Automation and is licensed under the Apache License 2.0 (see LICENSE).

It is built on Append HMI Studio, which is built on the draw.io diagram editor and drawio-desktop by JGraph Ltd, used and modified under the Apache License 2.0. NOTICE lists the third-party works. Append HMI Desktop is not affiliated with or endorsed by JGraph Ltd; "draw.io" is a trademark of its owner.