Ostrasort

Ostrasort is a mod manager for Ostranauts (Blue Bottle Games). You run it before you launch the game. It reads your whole mod setup, tells you in plain words whether it is healthy, and tries its best to help you fix things if there are any issues.

Why use Ostrasort?

Ostranauts loads mods in the order listed in a file called loading_order.json, and when two mods change the same thing the game keeps only one and drops the other without a word. Nothing tells you it happened. A mod you installed can just not work properly, an item can vanish from a shop, and the only sign is that the game does not behave the way the mod pages promised.

Sorting that out by hand means reading JSON, guessing the right load order, and hoping. Ostrasort does it for you.

What it does

It tells you if you are OK. A health card at the top of the window answers the one question that matters before you play. Green means there is nothing to do. Amber lists each issue in plain language with a one-click fix. Red means the game itself reported a problem from a mod on its last launch, and Ostrasort names the mod responsible and the next step to take.

It sorts your load order. It scans the base game plus every local, Steam Workshop, and BepInEx mod, works out what each one actually contains, and suggests a load order that follows the rules, with the smallest change to what you already have.

It merges conflicts. When two mods change the same thing, Ostrasort can build a small compatibility patch that keeps both. For example, shop inventories are combined so no mod loses its wares, and other game objects are merged field by field against the base game. Anything the two mods genuinely disagree on is yours to decide, through a short guided wizard with one plain question per choice and a suggested answer already selected. The merged results are best-effort, so it is worth a quick look in game.

Around those three jobs it is a full mod manager. It can

• turn any mod on or off, remove it, or install one from a .zip that never came through the Workshop (just drag it onto the window),
• save your setup as a named profile and switch between setups later,
• manage more than one game install, even on different disks,
• show each mod's version and last-updated date, and flag a Workshop mod with a newer copy waiting,
• keep a backup of every change, with full undo and redo,
• read the game's own log after a launch and point each error at the mod that caused it,
• and produce a shareable report, or a pre-filled bug report, in one click.

Everything above is also driven from the command line for scripting. The full walkthrough is in the documentation below.

A note on FFU and non-Workshop mods

Ostrasort supports FFU (Fight for Universe, Beyond Reach) and other mods installed outside the Steam Workshop. It reads FFU's own ordering rules and understands how FFU merges data as the game loads.

That said, Ostrasort recommends Steam Workshop mods only. FFU is built against one exact game version, so installing it stops you taking Ostranauts updates until FFU catches up, and a mismatch usually breaks the game outright. Ostrasort supports FFU so it can spot that for you and offer a reversible, one-click way out. The documentation covers the details.

Early development, use at your own risk

Ostrasort is in active development and not yet stable. It edits your loading_order.json and can create a mod folder (OstrasortPatch) in your game install. It keeps a backup of every load-order write and refuses to run while the game is open, but it can still misbehave in ways that break your mod setup or a save, or leave you needing to verify or reinstall the game.

The author accepts no responsibility for any damage to your game, mods, or saves. Back up your save folder first, and only use Ostrasort if you are comfortable recovering your setup yourself. By using it you accept that risk.

Quick start

Windows only (64-bit), no admin rights needed.

1. Download Ostrasort-win-Setup.exe from the latest release and run it. It installs Ostrasort for your user, adds Desktop and Start Menu shortcuts, and keeps itself up to date. (Prefer no install. Download Ostrasort-win-Portable.zip instead, unzip it anywhere, and run Ostrasort.exe.)
2. Close Ostranauts. Ostrasort will not change anything while the game is running.
3. Open Ostrasort. It finds your install on its own and lists every mod in load order.
4. Read the health card. Apply the suggested order and resolve conflicts if it asks, then launch the game and check the in-game MODS screen.

Your settings, profiles, and backups live in %APPDATA%\Ostrasort, so they survive updates and reinstalls.

Windows SmartScreen may warn on first run because the installer is not code-signed. Choose More info, then Run anyway.

Full walkthrough in docs/usage.md.

Documentation

• Using Ostrasort is the full player guide, covering the window tour, profiles, the conflict resolver, managing the patch, and the command-line reference.
• How it works explains load order in Ostranauts, how mods are classified, what collisions Ostrasort detects, profiles, and the safety model.
• FFU support is the deep dive on Fight for Universe: Beyond Reach — how it loads mods, how Ostrasort recognises and orders them, and the quirks (OstraAutoloader, version pinning, the manual FFU tag).
• Building and developing covers the build and publish steps and the code layout.

Licence and disclaimer

Released under the MIT License. Do what you like with it, just keep the copyright notice. Provided as is, with no warranty and no liability for damage to your game, mods, or saves (see the notice above). Not affiliated with Blue Bottle Games.