Manage your Minecraft experience.

The metadata-driven Minecraft launcher that stores each mod exactly once — zero-duplication instances, snapshots, and a built-in CLI with MCP mode for AI agents.

Screenshot of the Polymerium home screen
Win / Linux / macOS
MIT License
Fabric · Forge · NeoForge · Quilt

An Instance Is a Description, Not a Folder Copy

Polymerium describes your game setup with a lightweight profile.json — version, loader, mod list. Instances are built on demand from a shared cache using symlinks. No files are copied. That means zero duplication, instant modpack switching, and Git-friendly version control.

profile.json
{
  "version": "1.21.4",
  "loader": { "type": "fabric", "version": "0.16.9" },
  "packages": [
    "modrinth:sodium",
    "modrinth:iris",
    "modrinth:fabric-api"
  ]
}

Built for Efficiency

Modpack Marketplace

Browse, install, and update modpacks from Modrinth and CurseForge without leaving the launcher.

Screenshot of the Polymerium modpack marketplace

Zero Duplication

Every mod file is stored exactly once and shared across instances via symlinks. The more instances you run, the more disk you save.

Instant Switching

Switch between modpacks in seconds. Instances are built from metadata, not file copies.

Snapshots

Save, restore, and diff entire game states. Experiment without fear.

Git-Friendly Modpacks

An instance is a single JSON file. Version control your modpack like code.

Privacy First — No ads, no telemetry, no data collection. Open source under the MIT license.

A Look Inside

Screenshot of the instance overview with the launch pad

Instance Overview

Deploy, launch, and track play time from a single screen.

Screenshot of the package management page

Package Management

Every package one toggle away, versions pinned by stable Pref references.

trident — MCP server
$ trident instance create my-pack --version 1.21.4
$ trident package add modrinth:sodium
$ trident package add modrinth:iris
$ trident instance build my-pack
$ trident instance run my-pack
✓ Instance "my-pack" deployed and launched.
$ trident --mcp
MCP server listening on stdio... (30+ tools registered)
Exclusive

The Only Minecraft Launcher with Built-in MCP

Start the trident MCP server and let AI agents create instances, add mods, build deployments, and manage snapshots — 30+ tools covering the full workflow.

View MCP Docs

Frequently Asked Questions

Build Your First Instance in Minutes.

Download Polymerium and see what metadata-driven really means.

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