ModSync 2.0.0-rc1

Install on Steam Deck / Linux

Download the bundle for your machine: ModSync-2.0.0rc1-x86_64.flatpak for the Steam Deck
and other PCs, or ModSync-2.0.0rc1-aarch64.flatpak for ARM machines such as the Steam
Frame. Then in Desktop Mode either open it with Discover, or run:

flatpak install --user ModSync-2.0.0rc1-x86_64.flatpak   # or ModSync-2.0.0rc1-aarch64.flatpak
flatpak run io.github.skjiisa.ModSync

Full instructions, including the from-source route, are in the README.

Changes

Joining a vault now copies the other machine exactly instead of merging both
ways. A machine that already has mods asks whether to copy or merge, and
nothing it has is deleted: what differs is set aside in the instance. Sync also finds files changed on two machines at once
and lets you choose which version to keep. The window is redesigned to feel
native on a Steam Deck. Steam updating a pinned game (a verify, a lost pin, a
library move) was checked on a real install and is handled. Still to do
before 2.0.0: a full Steam Deck pass (#74) and Steam Frame documentation
(#73).

Changed

• "Copy from another machine" copies. Before, joining merged both machines:
  mods only on the joining machine spread to the one being copied, and where
  a file differed the newer one won on both. Now this machine only receives
  until it matches the vault; files that already match aren't downloaded
  again, and what is only here, or different here, moves to
  .modsync-before-join in the instance instead of being sent or deleted.
  The copy carries on across restarts and waits for the other machine to
  connect, and Play is blocked until it finishes. When this machine already
  has mods, joining asks whether to copy or merge (modsync sync join --merge).
• "Stop syncing" can pause instead of leaving the vault. Resuming carries over
  what changed meanwhile, removed mods included, which leaving and joining
  again can't.
• Redesigned the window to look at home on a Steam Deck: a flat matte
  charcoal theme with the app icon's blue as the only accent, in place of the
  painted night sky, glowing teal cards and boxed icons. The real app icon
  sits in the top bar and the section tabs are plain text. The focused row
  lights up white and shows the button that chooses it (A, the PlayStation
  cross, or Enter), and the hint bar's button glyphs match. Status reads as a
  colored dot and a word instead of a chip. Sync progress is a bar instead of
  a ring. While a repair is recommended it is the one blue action on Home and
  Play becomes a plain row. Labels and descriptions are shorter. Controller,
  Steam Input, keyboard, mouse and touch input work as before.
• Button hints no longer guess between a keyboard and a controller, which
  look the same when Steam turns the controller into keys. Wherever a
  controller may be in use, each hint shows the controller button and the
  keyboard key together, such as A / Enter. A machine with no controller
  shows only keys.

Added

• Sync lists files changed on two machines before they synced, anywhere in the
  synced folders (mods and downloads included), describes what differs in a
  mod list, plugin list or INI file, and keeps the version you choose. The
  other moves to .modsync-conflicts in the instance. modsync sync conflicts
  does the same from the command line.
• modsync sync status shows the vault, its machines, a copy under way and
  any conflicts waiting.
• With a vault, Play and Open MO2 first check whether changes from another
  machine haven't arrived yet or conflicts are waiting, and ask before playing.
• When the game needs a version ModSync's list of downgrade patches can't
  reach, the Game version sheet says if that list may be out of date: the
  latest couldn't be downloaded or read, or is for a newer ModSync, so it used
  the one saved last time or the one it came with. modsync game status says the
  same.

Fixed

• Installing SKSE over another build left the other build's scripts in
  Data/Scripts when their names differed only in capitals (2.0.20 has
  ActiveMagicEffect.pex, 2.2.6 activemagiceffect.pex). Wine could load
  either, and Steam refused to move the game to another library ("Content
  file locked"). Installing SKSE now replaces those in every spelling of the
  folder, never through a link out of the game folder, and the Game version
  sheet offers to reinstall SKSE when an older ModSync left them behind.
• A game newer than the downgrade patches (Steam updated past them) no longer
  says "Update Skyrim in Steam first". That advice is now kept for a game older
  than where the patches start.
• modsync game downgrade without a terminal to answer "Proceed?" stops with a
  message instead of a traceback. --yes still skips the question.
• The test suite no longer writes to the developer's own
  ~/.config/modsync/state.json.
• The X and Y keys now do what the controller's X and Y do (for example
  "Check again"), as the keyboard hints already said.

ModSync 1.1.0-beta2

Install on Steam Deck / Linux

Download the bundle for your machine: ModSync-1.1.0b2-x86_64.flatpak for the Steam Deck
and other PCs, or ModSync-1.1.0b2-aarch64.flatpak for ARM machines such as the Steam
Frame. Then in Desktop Mode either open it with Discover, or run:

flatpak install --user ModSync-1.1.0b2-x86_64.flatpak   # or ModSync-1.1.0b2-aarch64.flatpak
flatpak run io.github.skjiisa.ModSync

Full instructions, including the from-source route, are in the README.

Changes

Install MO2 now works on the Steam Frame. It was tested end to end on a
Frame with the aarch64 Flatpak: Install MO2 with no 7-Zip or cabextract on
the system, a reboot, then Steam's Play button through ModSync to Skyrim's
title screen. The same MO2-LINT fix should let Install MO2 work on a stock
Steam Deck, which is still to be tested. Also brings the consolidated Home.

Changed

• Consolidated navigation into Home, Sync and Settings. Home now offers MO2
  installation and selection, matching SKSE, relevant repairs and launch
  actions. Game and MO2 maintenance open in sheets with a fixed Close button.
  Home shows sync status only when sync is enabled, and includes Steam setup
  with the launch hook's current status. Missing SKSE is an optional suggestion
  that leaves Play primary and keeps controller focus on Play.
  The guided setup prepares MO2, then the game and SKSE, then optional sync.
  An early copy route pairs before checking the incoming setup's game version;
  version-dependent repairs wait for the source's version record to arrive,
  including after closing and reopening ModSync during the first sync.
  Home layouts are checked at the Steam Deck's 1280 × 800 resolution.
• Install MO2 uses MO2-LINT 7.0.3 (was 7.0.1) and works on ARM64 machines
  such as the Steam Frame. ModSync downloads MO2-LINT's aarch64 build there
  and its x86_64 build elsewhere, each checked against its own SHA-256. On
  ARM64, MO2-LINT installs an MO2 2.5.2 build whose USVFS files are the same
  backport "Apply ARM64 fix" installs, so ModSync shows the fix as installed
  right away. Apply is only needed for instances installed before. Other
  machines still need an mo2-lint built for them on PATH.
• On the Steam Frame, where Steam can't be closed, Install MO2 no longer asks
  to close Steam first, and modsync mo2 install no longer refuses while it
  runs. MO2-LINT leaves Steam running there, so a reboot afterwards lets
  Steam's Play button use the new instance.

Fixed

• Install MO2 failed on stock SteamOS, which has no cabextract, and on the
  Steam Frame, which also has no 7-Zip. MO2-LINT 7.0.2 and newer download
  them when the system lacks them.
• ModSync didn't recognize Mod Organizer 2 behind Steam's Play button when
  MO2-LINT 7.0.2 or newer installed it. MO2-LINT renamed its compatibility
  tool to mo2_<appid>_proton_redirector so Steam Cloud syncs saves, and
  ModSync only knew the old mo2_<appid>_redirector. The Play button hook
  now hands off to either one, preferring the new name.

ModSync 1.1.0-beta1

Install on Steam Deck / Linux

Download the bundle for your machine: ModSync-1.1.0b1-x86_64.flatpak for the Steam Deck
and other PCs, or ModSync-1.1.0b1-aarch64.flatpak for ARM machines such as the Steam
Frame. Then in Desktop Mode either open it with Discover, or run:

flatpak install --user ModSync-1.1.0b1-x86_64.flatpak   # or ModSync-1.1.0b1-aarch64.flatpak
flatpak run io.github.skjiisa.ModSync

Full instructions, including the from-source route, are in the README.

Changes

A beta of the controller-first interface, for testing an end-to-end install of
the Flatpak on a Steam Deck before 1.1.0. Also brings Play through MO2 from
Steam's Play button as Steam's own launch, the optional ARM64 USVFS fix and
Visual C++ runtime install, and an aarch64 bundle.

Added

• An ARM64 USVFS fix for the files shipped with MO2 2.5.2. "Apply ARM64 fix"
  appears under Mod Organizer, also while Steam waits on ModSync. It
  downloads a pinned build with the injection-stub stack-alignment fix,
  verifies the archive and each binary, and backs up the originals. The build comes from ModSync's mirror of
  ndabas's release, which also carries the source, with the original release
  as a fallback. "Restore original USVFS" reverses it.
  Unknown builds are left unchanged. The same actions are available through
  modsync mo2 usvfs status|apply|restore; doctor reports the fix's status.
  Changes are refused while MO2, or any game or tool it started, still has
  the files loaded. Tested on a Steam Frame: modded Skyrim through Steam's
  Play button and MO2, Apply and Restore from the launch hub, and offline
  reapplication from the cache.

• When an instance's USVFS is 0.5.7 or newer and the game's Proton prefix
  only has the old Visual C++ runtime (or Wine's stand-in), the app
  offers to install Microsoft's current runtime into the prefix. USVFS 0.5.7+
  uses the runtime of the programs MO2 starts, so without it nothing started
  from MO2 runs. The pinned, checked redistributable is installed silently
  through the game's Proton after backing up the DLLs it replaces; it never
  happens without a click. modsync doctor shows each instance's USVFS
  version and this check. Tested on a Steam Frame, from the Flatpak too.

• An aarch64 Flatpak bundle next to the x86_64 one, for ARM machines such as
  the Steam Frame. It bundles the arm64 Syncthing build. Not yet tested on an
  ARM device.

Changed

• Steam's Play button now leads to the same Play Skyrim and Open Mod
  Organizer 2 as opening ModSync directly: the selected MO2 profile, SKSE
  when it is installed, and the same checks. Before, Continue only carried on
  to whatever Steam was about to start, which without MO2-LINT's redirector
  was the unmodded game. ModSync hands the MO2 command line back to the
  launch hook, which runs it as Steam's own launch, so Steam still tracks the
  game and syncs its cloud saves when it exits. Verified on the desktop: a
  save written while MO2 ran under Steam was uploaded right after it closed,
  with a matching SHA-1. Continue remains for a machine with no MO2 instance
  chosen. Existing hooks are updated when ModSync opens.

• A new interface, designed for a controller first. The dashboard and its
  dialogs are gone. The window now has five sections (Home, Game, Mod
  Organizer, Sync and System), switched with LB and RB, Q and E, or by moving
  up onto the tabs. Every action is a large tile that shows the description a
  tooltip used to hide. A single outline marks the focused tile, and a hint
  bar shows which button does what, with PlayStation symbols for a
  PlayStation controller. Questions, text entry, PIN entry and folder picking
  open in sheets inside the window instead of separate dialogs, and the hint
  bar names what A does on the focused control. Text entry has an on-screen
  keyboard with a symbols layer, shifted punctuation, cursor movement,
  selection and a Paste key, and the PIN pad works like a combination lock.
  Home recommends a repair when the game version or SKSE does not match, or
  Steam has an update waiting. Play stays available with the consequence
  explained. Home has a readiness checklist (game version, SKSE, Mod
  Organizer 2, sync) next to Play, or Continue when Steam's Play button
  opened ModSync. The setup wizard reuses the same parts. Its last step keeps
  Finish at the top, or "Finish anyway" with the repair focused when the game
  version still doesn't match. System and Game use shorter tile
  descriptions, and System's settings details and controls open in their own
  sheets. B on Home, or "Quit ModSync" under System, asks to quit, so ModSync
  can be closed without a mouse. A mouse or touch screen works on its own
  too: sections scroll with a finger, the hint bar becomes buttons for Back,
  Cancel and Quit, and the PIN sheet has digits to tap. ModSync always uses its dark theme now.

• Controllers work two ways. Outside games, Steam Input's desktop
  configuration turns buttons into keys, and ModSync reads them back as the
  buttons that sent them: Space is Y on a Steam Deck and B on a Steam
  Controller, Xbox or PlayStation pad, Page Up/Down are X/Y on the latter, and
  a tap of Ctrl or Alt is LB or RB. It tells which applies from the hardware
  in /sys. ModSync also reads controllers directly through SDL2, from the
  Flatpak runtime or SteamOS, which covers the virtual pad Steam provides in
  Gaming Mode. A press that arrives both ways counts once, and presses are
  ignored while another window is in front. The Flatpak gains
  --device=input for this. MODSYNC_GAMEPAD=0 turns direct reading off.
  The controls are listed in docs/advanced.md.

• Steam's Play button opens the regular ModSync window instead of a separate
  launch hub. While Steam waits, Play turns into Continue, which hands the
  launch on to MO2-LINT or the game, and "Cancel launch" returns to Steam.
  Open MO2 is hidden then, so ModSync never starts a second Proton in the
  game's prefix next to Steam's. The Mod Organizer 2 card shows the selected
  profile and its enabled mod count. A warning above Continue says when the
  vault is still syncing. Esc no longer cancels the launch.

• Install MO2 uses MO2-LINT 7.0.1 (was 7.0.0-rc7). The download is checked
  against the release's SHA-256, and the cached copy is named by version so
  a new pin replaces the old binary instead of reusing it.

• On ARM64 machines such as the Steam Frame, the Play button hook finds
  Valve's ARM64 Proton builds and hands off to the one Steam would run.

• On machines other than x86_64, Install MO2 says up front that MO2-LINT
  only ships an x86_64 build. It no longer tries to run that build.

• When a game is left on "Default" in Steam, the Play button hook now hands
  off to the Proton Steam would pick: Valve's recommendation for the game on a
  Steam Deck or Steam Frame, then your global choice, then Proton stable. It
  used to prefer Proton Experimental.

• On the Steam Frame, where Steam can't be restarted, queued changes (the
  Play button switch, the update pin) tell you to reboot instead. The background
  service applies them before Steam starts. Tested on a Frame.

Fixed

• Play refuses an MO2 instance that hasn't been told which game it manages,
  and says to finish setting it up in MO2. MO2 would otherwise stop at
  "Select the game managed by this instance".

• Steam Cloud stopped syncing Skyrim saves while the Play button switch was
  on. Steam maps a game's Windows save folders into its Proton prefix only
  for a compatibility tool whose internal name contains "proton", and the
  hook was named modsync_489830_hub. Steam couldn't resolve the save folder,
  so it skipped every save while still reporting the sync as complete. The
  hook is now modsync_489830_proton. When ModSync opens or the
  background service starts, an existing hook is moved to the new name and
  Steam is switched over to it, after a Steam restart if Steam is running.
  Saves made under the old name are still in the prefix, where Steam finds
  them again once the game launches through the new name.

• In the Flatpak, modsync doctor and modsync diagnostics pointed at a
  launch hook log inside the sandbox that is never written. Steam runs the
  hook on the host, so they now read the host's ~/.local/state/modsync/launch-hook.log.

• When Steam couldn't be closed and you picked the Play button switch under
  Properties, then Compatibility yourself, ModSync kept saying it was waiting
  for Steam to close, and would have re-applied the switch the next time
  Steam closed, undoing any choice made since. A queued switch that is
  already in place is now dropped. Tested on a Steam Frame.

• With MO2-LINT's tool selected and the Play button switch off, the status
  now says Play opens Mod Organizer 2 (MO2-LINT), not the game directly.

• The Flatpak didn't recognise SteamOS: inside the sandbox /etc/os-release
  describes the Flatpak runtime. ModSync now reads the host's
  /run/host/os-release, so on a Steam Frame it says to reboot instead of
  restarting Steam, and Valve's Steam Deck/Frame Proton recommendations apply.
  Tested on a Frame.

• modsync service install failed in the Steam Frame's desktop terminal,
  because the nested Plasma session's XDG_RUNTIME_DIR has no systemd user
  bus. ModSync now falls back to the login session's. The Flatpak failed the
  same way, since flatpak-spawn --host runs systemctl in that nested
  session, and now passes the login session's directory to the host.

• On ARM64, ModSync no longer picks one of Valve's x86_64 Protons, which can't
  run there. When Skyrim is set to a Proton with no ARM64 build, the launch
  hook and Open MO2 use Steam's ARM64 default, as Steam does.

• MO2 2.5 crashed at start-up, writing hundreds of crash dumps, when Skyrim's
  Proton prefix had only the 2016 Visual C++ runtime that the game installs.
  When the prefix's runti...

ModSync 1.0.0

Install on Steam Deck / Linux

Download ModSync-1.0.0-x86_64.flatpak, then in Desktop Mode either
open it with Discover, or run:

flatpak install --user ModSync-1.0.0-x86_64.flatpak
flatpak run io.github.skjiisa.ModSync

Full instructions, including the from-source route, are in the README.

Changes

First stable release. Everything in the two release candidates, now tested end
to end on a Steam Deck and on a fresh Linux user account: the guided Mod
Organizer 2 install, game version detection with downgrade and Steam pin,
SKSE installation, the Steam Play button hook, and optional sync between
machines.

Changed

• Rewrote the README and moved the technical detail into docs/advanced.md.
• Plainer wording throughout the app: shorter tooltips and dialogs, no
  decorative symbols, and the launch hook status no longer says "off" twice.

ModSync 0.1.0-rc2

Install on Steam Deck / Linux

Download ModSync-0.1.0rc2-x86_64.flatpak, then in Desktop Mode either
open it with Discover, or run:

flatpak install --user ModSync-0.1.0rc2-x86_64.flatpak
flatpak run io.github.skjiisa.ModSync

Full instructions, including the from-source route, are in the README.

Changes

Everything the first real desktop ↔ Steam Deck pass turned up. Pairing through
a desktop firewall, a receiving machine that syncs before it checks the game
version, SKSE installed from the Game card, and MO2 installs from the Flatpak.
Not yet exercised on the Deck itself: the join-then-auto-refresh flow and the
desktop-hosts pairing direction — this build is for that.

Fixed

• Joining a vault no longer carries this machine's own game-version record into
  it. Choosing an instance records the local runtime in modsync-vault.json;
  on a machine about to copy its mods from another one that file was newer than
  the vault's and won Syncthing's conflict resolution, so the two machines could
  end up disagreeing about the version the setup was built for.

• "Install MO2…" works from the Flatpak. It refused with "protontricks is not
  installed" because it looked inside the sandbox, and would then have run
  MO2-LINT inside the sandbox, where Steam and Proton aren't visible. The
  check now asks the host for what MO2-LINT really needs (pgrep, xdg-mime;
  protontricks is bundled in MO2-LINT) and the install runs on the host.

• Reinstalling MO2 into a folder MO2-LINT still lists (after "Reset setup" and
  deleting the instance) no longer fails with "An instance with the specified
  directory already exists": ModSync has MO2-LINT forget the stale entry first.
  A folder that really holds a registered instance is refused with a pointer
  to "Use" instead, and a failed install no longer leaves an empty folder.

• Network pairing behind a firewall. The PIN handshake now listens on a fixed
  port (TCP 21029, the same number as the UDP discovery port) instead of a
  random one, so a single firewall rule covers pairing. Announcements also go
  to each interface's own broadcast address, not only 255.255.255.255.

Changed

• The setup wizard asks about sync before the game version, and a machine that
  copies its mods from another one finishes there: it can't know which version
  the mods need until they've arrived. The dashboard's Game card now re-checks
  by itself when the vault's version record changes and when the folder first
  finishes syncing, so the downgrade / SKSE advice appears without a manual
  refresh.
• Network pairing is harder to get lost in: the machine with the mods shows
  the PIN large inside the Sync card (with the joiner's steps and its own
  address) instead of only in the status line, and on the other machine
  picking a listed machine opens a "Pair with …" dialog that asks for that
  PIN. The first-run wizard numbers the same two steps.

Added

• On this machine detects a running ufw/firewalld at launch and reads
  whether ModSync's ports are allowed (firewall-cmd --query-port /
  /etc/ufw/user.rules, falling back to the rules file's mtime where it isn't
  readable). Allow in firewall… adds the rules through pkexec; once
  they're in, the same button becomes Remove firewall rules… so the ports
  can be closed again after a sync or before uninstalling. Also
  modsync firewall status | allow | remove.
• After LAN pairing, Syncthing is told the peer's address directly instead of
  relying on its own LAN discovery, so a firewalled machine only needs to dial
  out.
• The joiner can type the host's address when the scan finds nothing (the host
  shows its address next to the PIN), and "No machines found" / "could not
  reach" messages now say which ports to open. The README documents the ports.
• Pairing logs what it announces, receives and connects to, so a bug report
  can show where discovery broke.

ModSync 0.1.0-rc1

Install on Steam Deck / Linux

Download ModSync-0.1.0rc1-x86_64.flatpak, then in Desktop Mode either
open it with Discover, or run:

flatpak install --user ModSync-0.1.0rc1-x86_64.flatpak
flatpak run io.github.skjiisa.ModSync

Full instructions, including the from-source route, are in the README.

Changes

First public pre-release. Ships as a Flatpak bundle attached to the GitHub
release; there is no Flathub listing. Tested on a desktop Linux install
(native and Flatpak Steam); the Steam Deck pass is what this release candidate
is for.

Added

• modsync --version.
• Release workflow: pushing a v* tag builds the Flatpak bundle and the
  Python wheel/sdist and publishes them as a GitHub (pre-)release.

Changed

• Add a prominent Play Skyrim button that launches through the chosen MO2
  instance and selected profile, preferring SKSE. Add a separate Open MO2 button.

• Use the updated inset Canva icon with deeper transparent rounded corners,
  preserving the supplied artwork in both the scalable SVG and 512px PNG.

• Shorten Skyrim version warnings and show the next action in
  plain language. Keep technical version details in a tooltip.

• Refresh the dashboard, setup wizard and launch hub with shared light/dark
  styling, readable secondary text, larger controls, visible keyboard focus
  and padded warnings. Replace all uses of Qt's border color for text.

• Wrap game actions and stack dashboard cards in narrower windows; keep wizard
  navigation outside its scrolling content. Show sync progress before pairing.

• Clarify that the Steam shortcut button adds ModSync as a non-Steam shortcut.

• Open the installation step directly from “Install MO2…”, add wizard step
  labels, and allow returning to the dashboard from any idle setup step.

Fixed

• Install files that the downgrade archives ship whole, such as 1.5.97's
  binkw64.dll and Skyrim - Patch.bsa. Without them the downgraded game exited
  at startup. Restoring a downgrade removes them again.

• Show SKSE mismatch and pending Steam update warnings at normal text contrast,
  including before an MO2 instance is chosen.

• Keep the dashboard, setup wizard and launch hub open while a downgrade,
  restore or MO2 install is running. Restore now blocks competing game actions
  and launching the game until it finishes; controls recover after failures.

• Stop dashboard polling and network pairing when opening the setup wizard.

• Clear old network pairing results when rescanning, so selecting a scanning
  or failure message cannot join a machine from the previous scan. The setup
  wizard disables Finish until a machine from the new results is selected.

Added

• Discovery (modsync doctor, stdlib only): finds Steam libraries, the
  Skyrim SE install and its Proton prefix, and existing MO2 instances.
• Guided Mod Organizer 2 install as a portable instance wired into the
  game's Proton prefix, using MO2-LINT as the backend (modsync mo2 ...).
• Game version management: detects the installed Skyrim SE runtime and the
  SKSE runtime, downgrades the game natively with community xdelta patches from
  a bundled, auto-refreshed recipe index, and pins Steam so the downgraded
  install keeps launching (modsync game status | downgrade | pin).
• Optional sync between machines with a bundled Syncthing daemon:
  vault create/join, PIN-based LAN pairing, per-machine ModOrganizer.ini
  (modsync sync create | join).
• Background service (modsync serve, modsync service install [--linger]) that runs as a systemd --user unit and works without a vault.
• PySide6 UI: first-run wizard (instance, game version, optional sync) and a
  dashboard with independent Game, Mod Organizer 2 and Sync cards.
• Steam integration: add ModSync as a non-Steam game for Gaming Mode
  (modsync steam shortcut) and a launch hook that opens ModSync when Skyrim
  is launched from Steam (modsync launch enable | disable | status).
• Flatpak packaging under packaging/flatpak/ (manifest, desktop entry,
  AppStream metainfo, icon) with bundled Syncthing, xdelta3 and 7zz.
• App logo and window icon; GPL-3.0-or-later license.
• Scheduled workflow that keeps the downgrade recipe index in step with
  Mulderland's recipe.
• CI (unit tests, desktop/AppStream validation, flatpak-builder-lint),
  CHANGELOG, CONTRIBUTING guide and issue templates.