Frequently Asked Questions - fp-appimage-updater

Do I need root or sudo to use fp-appimage-updater?

No. fp-appimage-updater operates entirely in user-space. All files — AppImages, symlinks, desktop entries, and icons — go under ~/.local/. You only need sudo if you choose to install the tool itself system-wide using the --system flag during installation.

Can I use it on an immutable or atomic Linux distribution?

Yes. fp-appimage-updater is designed to work on immutable distributions like Fedora Silverblue and openSUSE MicroOS. All runtime files are written to user-space paths. If you attempt a system-wide install (--system) on a strictly immutable environment, the install script will reject the request.

How do I stop fp-appimage-updater from updating a specific app automatically?

Set ignore: true in the recipe to keep the app in your config while skipping it in check and update.If you want to keep the recipe but skip rate-limit cooldowns, set respect_rate_limits: false globally in config.yml or per-app in the recipe:

respect_rate_limits: false

What happens to my AppImage if an update fails mid-download?

The existing AppImage is not replaced until the download completes successfully. A failed or interrupted download leaves the current version intact.

Does fp-appimage-updater have a GUI?

No — it is an intentional CLI-only tool and will never have a GUI.

How do I update fp-appimage-updater itself?

Run the self-update command:

fp-appimage-updater self-update

To fetch a pre-release version, add --pre-release:

fp-appimage-updater self-update --pre-release

Can I use a custom configuration directory?

Yes. Pass -c or --config before any subcommand to override the default ~/.config/fp-appimage-updater/ path:

fp-appimage-updater -c /path/to/my-config check

This flag works with every command.

Where does fp-appimage-updater remember what I already installed?

It keeps a small cache in ~/.local/state/fp-appimage-updater/cache.json. That file stores the last known version, download metadata, the installed file path, and any rate-limit or capability hints from the previous run.If the cache is missing, fp-appimage-updater rebuilds it the next time you run check or update.

What is the zsync field in an app recipe?

The zsync field enables delta updates, which download only the bytes that changed instead of the full AppImage. Set it to true to derive the .zsync URL from the resolved download URL, or provide an explicit URL:

zsync: true

zsync: "https://example.com/app.AppImage.zsync"

fp-appimage-updater uses its built-in zsync-rs backend for this, so you do not need to install a separate zsync system package. It only uses the delta path when it already has a local AppImage to compare against, and it falls back to the normal download path if the delta update cannot run.

Why is an app being skipped during updates?

The app may have been rate-limited on a previous run. When a rate limit is hit, fp-appimage-updater records the retry window and skips that app on subsequent runs until the window expires.Check the current status of a specific app:

fp-appimage-updater check <app-name>

To disable this behavior globally, set respect_rate_limits: false in your config.yml. You can also set it per-app in the recipe file.

Can I define multiple apps that come from the same repository?

Yes. Each recipe must have a unique name field, but multiple recipes can point to different assets from the same repository. As long as each recipe has a distinct name and its asset_match pattern selects a different file, they are managed independently.

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