For a long time, the original Steamtools was popular for manifest sideloading, but it was closed-source, proprietary, and eventually abandoned.
The community created OpenSteamTool (and now the actively maintained BetterSteamTools fork) to replace it with a transparent, open-source C++ engine. However, these tools are bare DLLs without a user interface—forcing people to manually extract files, edit .toml configs, and dig through Steam folders.
TOST is the missing open-source GUI: it brings back the dead-simple floating drag-and-drop icon, powered entirely by open-source community tools under the hood.
- One-click engine setup: Right-click the floating icon → Apply OST to automatically fetch and configure the latest unlocker.
- Drag-and-drop routing: Drop
.manifest,.lua, or.zipfiles onto the icon to install them into Steam. - Game Manager: View and remove installed games and manifests cleanly.
- Windows: Download
TOST-Setup.exe(orTOST-Portable.zip) from the Releases page. - Linux: Run the one-line install command:
(Or grab the
curl -sSL https://raw.githubusercontent.com/sadabx/TOST/main/install.sh | bash.AppImage,.deb, or.pkg.tar.zstmanually from Releases).
- Launch TOST. A small floating icon will appear on your desktop.
- Right-click the icon and click Apply OST (Windows) or Apply SLSsteam (Linux) to set up the engine.
- Drag and drop your
.manifest,.lua, or.zipfiles onto the icon. - Restart Steam and you're good to go!
Tip
Important: Whenever you first install TOST, update TOST, or after a major Steam client update, always open the menu and click Apply OST to ensure the latest hook files are active inside Steam.
Note
Linux Users: Active Linux development on TOST is currently on pause. For a complete automated Linux setup to download and unlock games, we recommend checking out Enter the Wired (Accela + SLSsteam combo installer).
Requires .NET 8.0 SDK.
git clone https://github.com/sadabx/TOST.git
cd TOST
dotnet run --project desktop/TOST.Desktop.csproj(Architecture and technical details are in docs/ARCHITECTURE.md.)
- BetterSteamTools by madoiscool — The actively maintained Windows backend engine.
- OpenSteamTool — The original open-source Windows hook foundation.
- SLSsteam by AceSLS — Linux Steam client modding & backend.
This project is for research and educational purposes only. TOST is not affiliated with, endorsed by, or connected to Valve, Steam, OpenSteamTool, or SLSsteam.
Distributed under the GNU General Public License v3.0. See LICENSE for details.