Multron Updater

Multron Updater keeps a Windows program up to date straight from a GitHub repository. It watches a file or folder in a repo, and when it changes it downloads the new version, closes the running program, replaces the files and starts the program again — automatically, from the system tray.

Built with C# / WPF on .NET 8.

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Features

• Multiple targets – add as many repo → program pairs as you like, each with its own settings. Enable, duplicate or remove them from the list.
• GitHub as the update source – pick any owner, repository, branch and path (a single file or a whole folder).
• After-update actions per target – start the program again and/or refresh the active Microsoft Edge tab (F5).
• Windows and console programs – start arguments, and for console apps: show the window, keep it open after exit, or run hidden with the output written to a log file. Console apps are closed with Ctrl+C before an update.
• Paste-a-link setup – paste a GitHub link and the fields fill themselves in.
• Safe update flow – download → verify → close the program → replace files → restart. If replacing fails, the previous version is restored automatically.
• Only changed files are downloaded – local files are compared with GitHub's blob hashes (the same hash git uses).
• Automatic updates (optional) – turn it on with one switch and choose how often to check (in minutes).
• Runs in the background – closing the window keeps it running in the system tray.
• Download animation – a popup slides in at the bottom-right, the taskbar button shows a progress bar and the tray icon spins while an update downloads.
• Log system – color-coded log levels (Info / Success / Warning / Error) with filtering and search, also written to a log file.
• Backups – replaced files from the last 3 updates are kept.
• Private repositories – optional personal access token, stored encrypted (Windows DPAPI) for the current user.
• Start with Windows – registered as a logon task, so it starts without a UAC prompt.
• Auto-saving settings – every change is saved as you type.
• Updates itself – every push to main builds a new release, and Multron Updater installs it and restarts.

Requirements

• Windows 10 / 11 (x64)
• .NET 8 Desktop Runtime
• Administrator rights (the app asks for them on start, so it can close and replace programs that run elevated)

Getting started

1. Download MultronUpdater.exe from the latest release and run it.
2. In the Targets tab, select a target (or click + Add) and give it a name.
3. GitHub source – paste a link such as https://github.com/user/repo/blob/main/bin/Release/App.exe and click Fill from link, or enter Owner, Repository, Branch and Path in repository by hand.
4. Program on this computer – choose the target folder and, optionally, the .exe that should be closed while the files are replaced.
5. After updating – choose whether to start the program again and/or refresh the active Edge tab.
6. Click Check this target to run the first update. Repeat for more targets.
7. In the General tab, turn on Update automatically to keep every enabled target updated in the background.

Update source

Each target chooses where updates come from (GitHub source → Update source):

Option	What it does
Repository files + releases (default)	Files under Path in repository are kept in sync with the branch, so a push is seen right away. New releases install the files the repository does not have; a file that exists in both is taken from the repository.
Repository files only	Raw files from the branch. Each file is checked with its git hash; if a <file>.sha256 sits next to it in the repository, the SHA-256 is verified too.
Releases only	Installs the file(s) of the latest GitHub release, verified with the SHA-256 GitHub publishes for every asset.

Release file(s) to install takes a file name, wildcards (MyApp-*-win64.zip) or several names separated by ;. When it is empty, the name of the program (or of the file in Path in repository) is used. A single .exe asset is installed under the program's name, and .zip assets are extracted into the target folder (a single top folder inside the zip is skipped). Show latest release lists the files of the latest release and marks the ones that match.

Checking for a new commit or a new release tag does not use the GitHub API, so frequent checks do not run into the 60 requests/hour limit; the API is only called when something actually changed.

Console programs

In Program on this computer, choose Console app (it is detected automatically when you pick the .exe with Browse...) and, optionally, Start arguments such as --port 8080 --silent. Then choose how the console window behaves:

Option	What happens
Show the console window	The program opens in its own console window.
Show it and keep it open after the program exits	Runs inside cmd /k, so the window stays open to read errors.
Run hidden in the background	No window; output and errors go to %AppData%\MultronUpdater\console-logs\<target>.log (Open console log).

Before replacing files, Multron Updater sends Ctrl+C so the program can shut down cleanly and terminates it only if it is still running after 5 seconds. Use Start now to try the settings without waiting for an update.

File groups

Turn on Update only the checked files, in groups to pick exactly which files are updated:

• Load from GitHub lists the files under the path and marks them: yellow • changed, green + new, grey ✓ up to date, red − not found on GitHub.
• Drag files or folders from File Explorer onto a group (or use Add files...). They must be inside the target folder. Dropping a file that is already listed onto a group moves it there.
• Create groups with + New group, rename them by clicking the name, and drag files between groups (or right-click a file → Move to group).
• Each group has its own Enabled, Restart the program and Refresh Edge (F5) options. A group's actions run only when one of its files changed.

Refreshing Microsoft Edge

With Refresh the active Microsoft Edge tab (F5) enabled, Multron Updater brings the most recently used Edge window to the front after the update, presses F5 and then gives focus back to the window you were using. This is handy when the target is a web page or a local web app.

File or folder?

Path in repository	What is synced
bin/Release/App.exe	Only that file
bin/Release	Every file inside the folder (sub-folders included)

Tip: For .NET apps that are not published as a single file, the .exe is only a small launcher and the real code lives in the .dll next to it. Use the folder path in that case.

How it works

1. Asks GitHub for the latest commit of the branch. This request uses an ETag, so when nothing has changed it does not count against GitHub's rate limit.
2. If the commit changed, reads the file list and compares each file with the local copy.
3. Downloads the changed files (pinned to the exact commit) and verifies their hashes.
4. Closes the program (gracefully first, forcefully after 5 seconds).
5. Backs up and replaces the files, then runs the after-update actions (restart the program, refresh Edge).

Targets are checked one after another.

Where things are stored

What	Location
Settings	%AppData%\MultronUpdater\settings.json
Log file	%AppData%\MultronUpdater\log.txt
Backups	%AppData%\MultronUpdater\backups\<target id>\
Console output (hidden console apps)	%AppData%\MultronUpdater\console-logs\

GitHub rate limit

Without a token GitHub allows 60 API requests per hour. Unchanged checks are free (HTTP 304), so a 5-minute interval works fine. If you hit the limit, or the repository is private, add a personal access token (read-only Contents permission is enough).

Updating Multron Updater itself

1. A push to the main branch starts the Build and release GitHub Actions workflow (.github/workflows/release.yml). Pushes that only change *.md, LICENSE or .gitignore are skipped.
2. The workflow builds the single-file exe and publishes it as a release named v<major>.<minor>.<run number>. Major and minor come from <Version> in MultronUpdater.csproj, so change it there to start a new series (e.g. 1.2.0).
3. Multron Updater checks the latest release 20 seconds after it starts and then every 3 hours (or on General → Check for updates). When a newer version exists it downloads it, checks its size and SHA-256, swaps its own exe and restarts in the same state (window open or in the tray).

Turn off Update Multron Updater automatically in the General tab to only get a notification and install the update with the Install button. Development builds (running from bin\) never update themselves.

Building from source

Requires the .NET 8 SDK (or newer).

build.bat

build.bat publishes a single-file exe to publish\MultronUpdater.exe. If Multron Updater is running, it closes it first (it may ask for administrator permission).

Or manually:

dotnet publish -c Release -o publish

Do not publish into a folder that contains the project folder — the SDK then excludes the source files from compilation and produces a broken exe.

Limitations

• Files deleted from the repository are not deleted locally.
• Files stored with Git LFS are not supported.
• Very large repositories (100,000+ files) may return a truncated file list from GitHub.