Staying safe
Fusion runs other programs and changes games, so it's worth knowing exactly what it does.
What Fusion does to your games¶
- It starts them for you, the way their router says (usually through Steam), hidden behind Fusion's window.
- Setup changes files only through a recipe with undo. One-click setup writes down every file it adds or replaces; Undo setup in My Games puts them back. Close the game first.
- It talks to a game through a small kit inside the game (a mod, or Fusion's guest SDK). The kit only answers Fusion's questions on your own PC; nothing goes over the internet.
- It never copies a game's files out of the game, and never shares them. Share and publishing compare every file against your installed games and refuse a package that holds one.
Your saves¶
A router may load a save of its own (The Long Dark's router plays a save named "Fusion", never yours). Routers are new, so back up your saves before you try a game the first time.
Signatures and tiers¶
Every update of Fusion and every hub package is signed. Fusion checks each signature itself:
| Tier | Who signed it | May contain |
|---|---|---|
| Official | SteonMod | anything |
| Verified | an author SteonMod checked | anything, after review |
| Community | its author | text, Lua, pictures, sounds, models: no program files |
| Unsigned | nobody | the same as community, with a stronger warning |
Lua in routers, addons and Devices runs in a sandbox with time and memory limits: it can't open your files or the internet.
Anti-cheat and online games¶
Fusion is for single-player games. It refuses to attach to a game whose anti-cheat is running, and a game with anti-cheat only works through its own official offline mode. Never use Fusion online against other players.
What leaves your PC¶
- Update checks: Fusion asks steonmod.com for its release list (Settings → Updates).
- Content hubs: it reads their lists and downloads packages you install.
- Compatibility reports, only if you turn them on (Settings): the router, its version, the game's build, worked or broke, and Fusion's own words about what went wrong. No names, paths or files.
Nothing else. No account, no tracking.
If something looks wrong¶
A router asking for something strange, a package Fusion warns about, a crash: tell us in the Help forum. If a router is harmful we take it down for everyone through the signed feed.