Installation
Download, install, and set up Polymerium on Windows, macOS, or Linux.
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Download
Grab the latest release for your platform from GitHub Releases.
| Platform | File |
|---|---|
| Windows x64 | Polymerium-win-Setup.exe |
| Linux x64 | Polymerium.AvaloniaImage |
| macOS ARM | Polymerium-osx-Setup.pkg |
Each platform uses its standard installer format. Run it and follow the prompts.
macOS: PKG Installation Notice
Because the PKG installer is not signed with an Apple Developer certificate, macOS Gatekeeper may block it with a "damaged" warning. To install:
- Right-click the
.pkgfile and choose Open. - If that doesn't work, remove the quarantine flag from Terminal:
xattr -d com.apple.quarantine Polymerium-osx-arm64-Setup.pkg- Open the
.pkgfile again and follow the installer.
This is a one-time workaround. A future release may switch to DMG distribution which avoids this issue.
Windows: Enable Developer Mode
Polymerium uses symbolic links to share mod files across instances without duplication. On Windows, creating symlinks requires Developer Mode.
- Open Settings → System → For developers
- Toggle Developer Mode on
- Confirm the prompt
This is a one-time setup. It doesn't compromise security — it only allows your user account to create symbolic links, which is the default on macOS and Linux.
macOS and Linux users don't need any special configuration — symlinks work out of the box.
First Launch: The OOBE Wizard
When you open Polymerium for the first time, the OOBE (Out-of-Box Experience) wizard walks you through:
- Welcome & Features — a quick overview of what Polymerium can do.
- Privilege Check — Polymerium tests whether it can create symlinks in its data directory. If this fails on Windows, you need to enable Developer Mode (see above).
- Quick Setup — optionally configure Java paths and language.
- Privacy — choose whether to send crash reports via Sentry.
- Done — you're ready to create your first instance.
What Gets Installed Where
Starting with 1.10.0, Polymerium follows each platform's standard directory conventions instead of bundling everything under one folder. Data is split into four categories, each placed in the location the OS expects:
- Config —
settings.json - Data — the persistence database (
persistence.sqlite.db) and first-run marker - Cache — the HTTP cache (
cache.sqlite.db), crash-report cache, and the shared cache: mod files, game assets, and Java runtimes (underpackages/,assets/,runtimes/) - Instances — your Minecraft instances
| Category | Windows | Linux | macOS |
|---|---|---|---|
| Config | %APPDATA%\Polymerium | ~/.config/polymerium | ~/Library/Application Support/dev.dearain.Polymerium |
| Data | %LOCALAPPDATA%\Polymerium | ~/.local/share/polymerium | (same as Config) |
| Cache (HTTP + crash reports) | %TEMP%\Polymerium | ~/.cache/polymerium | ~/Library/Caches/dev.dearain.Polymerium |
| Cache (shared: mods/assets/runtimes) | %TEMP%\Trident | ~/.cache/trident | ~/Library/Caches/dev.dearain.trident |
| Instances | %LOCALAPPDATA%\Trident\instances | ~/.local/share/trident/instances | ~/Library/Application Support/dev.dearain.trident/instances |
Behavior change since 1.10.0 — before 1.10.0, Polymerium stored everything under a single
~/.trident/directory on every platform (settings under~/.trident/.polymerium/, the shared cache under~/.trident/cache/, and instances under~/.trident/instances/). For backward compatibility, if a~/.trident/directory already exists from a previous install, Polymerium keeps using it instead of switching to the per-platform locations above — so existing setups are not disturbed. Brand-new installs get the split layout automatically.Want to place data on a different drive, or force the classic single-root layout? See Custom Data Directory →.
Next Step
Now that Polymerium is running, create your first instance →