Install NoderaMC

The app, the mod, and what to do when the node cannot take its port. Ten minutes, and nothing to rent.

Install the companion app first, then the mod. The mod does not work on its own: it talks to a headless worker process on your own machine, and the app is what installs and supervises that worker.

What you need


Minecraft	1.21.1
Loader	NeoForge 21.1.238
Java	21

These are pinned rather than "or later". The mod reaches into the game's internals to run regions deterministically, and a different Minecraft or NeoForge build is a different set of internals.

1. Install the companion app

Take the installer for your platform from the download page. The file names are fixed: nodera-app-<system>-<arch>.<ext>.

Windows

Run nodera-app-windows-x64.msi. Pick the arm64 installer only if you know the machine is a Windows-on-ARM device — it will say so under System → About.

Linux

sudo apt install ./nodera-app-linux-x64.deb on Debian and Ubuntu derivatives. A .deb is the only Linux installer published, so on other distributions build one: with a JDK, cargo and bun present, run scripts/release.sh --component app in a checkout and the installer is staged into build/release/.

Android

One APK — nodera-app-android-universal.apk — carries every ABI, and it is sideloaded: there is no store listing. The phone runs the same worker the desktop does, so it is a real peer rather than a remote control.

Start the app once after installing. It unpacks and starts the worker, which generates this install's identity and listens on 127.0.0.1:25610. Nothing is announced to any network until you share a world.

2. Install the mod

Settings → Minecraft lists every Minecraft installation the app found, the mods/ folder inside each, and whether a Nodera jar is already there. Press Install on the profile you play, and the app copies the jar it shipped with into that folder.

That is the whole installation. There is no separate library jar and no config to write before the first launch — the mod writes config/nodera-client.toml itself on first run.

The app installs only the jar in its own bundle, never a downloaded one, so the mod and the worker are always the same build and cannot disagree about the wire. The same screen offers Update when the installed jar is older, and Uninstall, which removes only a jar this app put there.

3. Start the game

Launch Minecraft with the app running. Two things on the title screen tell you the halves found each other: vanilla's Realms button has become Nodera Network, and Multiplayer opens NoderaMC's own screen instead of the server list.

If the game closes on startup

The crash message names the reason, and one reason accounts for most of them.

"Nothing answered on 127.0.0.1:25610." The worker is not running. Open the companion app, leave it running, and start the game again. If the app is running and the game still cannot reach it, something on your machine is holding that port or blocking loopback traffic — a local firewall or a security suite with a "block all local servers" setting is the usual culprit, not the app.

Two ways out, in the order you should try them:


Two games on one machine	Both default to the same worker and the same `~/.nodera`, so one node ends up wearing two hats — one identity, one world registry, two players who each believe they are its author. Set `NODERA_CONTROL_PORT` and `NODERA_STATE_DIR` for the second one.
Load the profile without a node	Set `companion.required = false` in `config/nodera-client.toml`. The game starts and every NoderaMC feature is inert, because there is no node. It is a way to load a profile that has the jar in it, not a way to play.

What is installed where

The app installs itself the way any application on your platform does, and unpacks the worker alongside itself. Per-install state — your node's identity, the worlds you host, the pieces you hold for other people's worlds — lives in ~/.nodera, outside the game. Your Minecraft saves are untouched: NoderaMC reads and writes a world through the game, never behind its back.

Updating

Neither half updates itself. Both are file replacements:

The app — run the newer installer over the old one.
The mod — replace the jar in mods/. There is no migration step and no state in the jar.

Keep the two in step. The mod and the worker speak a versioned control protocol and the mod checks it at startup, so a mismatch is an error naming which half is behind — "update the companion app" or "update the mod" — rather than something you discover an hour later.

Share a world, and join one. Or, if you are setting this up for someone who is not going to install a mod, read playing with no mod installed first.