What NoderaMC is
A Minecraft world hosted by the people playing in it, validated by more than one of them, and kept alive when any of them leaves.
A Minecraft server does two jobs: it decides what happened, and it stays switched on. NoderaMC splits them. Deciding is done by the machines that are playing, collectively and checkably. Staying switched on is done by a small background process on those same machines, which keeps running with Minecraft closed.
Nobody rents anything, nobody is an administrator by virtue of owning the hardware, and the world does not end when the person who started it quits.
The four parts
| Part | What it is | Runs where |
|---|---|---|
| The mod | The NeoForge mod, on Minecraft 1.21.1. Adds Open to Nodera, replaces the multiplayer screen, and drives the validated lane. | Inside the game |
| The worker | A headless always-on process — your node. Holds your identity, keeps your worlds announced, serves their pieces, validates regions. | Beside the game, supervised by the companion app |
| A tracker | Answers one question: who is on this world. | Somebody's server, or yours |
| A rendezvous relay | Introduces two machines that are both behind a NAT, and carries an encrypted circuit when there is no direct path. | Somebody's server, or yours |
Neither service is trusted with anything. See below.
Regions
The world is cut into a fixed grid of 8×8-chunk regions — 128 blocks square.
A region is the unit of everything: what gets simulated, what gets validated, what gets stored, what gets handed from one machine to another. The grid is fixed rather than dynamic because two machines that disagree about where the boundaries are cannot agree about anything else either.
Which regions your machine is responsible for follows you. Your render distance describes a disc around you, and the regions that disc touches are the ones you activate. Walk far enough and the set is recomputed; the region behind you is picked up by whoever is still near it.
Committees
Each active region has a small committee of peers, one of which is the primary.
The primary simulates the region for a batch of ticks. The others re-execute the same inputs
independently, and all of them compare a short fingerprint of the resulting world state — a
StateRoot. The batch commits only if a quorum agrees on that fingerprint, and does not
commit otherwise.
The default committee wants three validators (committee.requiredValidators). That is
why no single machine — including the one that created the world — is trusted to say what happened
in it, and why a world with too few peers present reports itself as running with fewer validators
than it wants rather than pretending.
Trackers and relays hold no authority
Two machines have to find each other, and most home connections cannot be dialled directly. A tracker answers "who is on this world"; a relay bridges two machines behind NATs.
Neither is trusted. Every service proves its own identity before a peer will talk to it, and everything a service says about a world, an identity or a vote is checked against signatures the peers already hold. The most a hostile or broken service can do is hide a peer from you, or point you at one that is not reachable.
That is an availability problem, never a correctness one — which is exactly why the app will take a list of services from anyone, and why the bundled list is deletable like any other.
The worker, and why the mod refuses to start without it
The worker runs whether or not Minecraft is open, which is the entire reason your world does not vanish when you quit. It is also where your identity lives, so the same node is recognisable across sessions.
The mod requires it. If nothing answers on 127.0.0.1:25610 when the game starts, the
mod aborts with an install prompt rather than pretending to work. The companion app is what
supervises the worker, which is why the app is installed first.
Nobody has to stay
A world is stored as content-addressed pieces, and every peer that has played in it holds some of them. When the machine that started it goes away, the remaining players elect one of themselves, and that peer opens the world and announces that it is now serving it. Everyone else is reconnected to it. When the host leaves is that mechanism in full, including what it does not promise.
What NoderaMC is not
It is not a way to play with people who have not installed it. Every player in a NoderaMC world runs the mod and joins as a peer. The mod makes that visible: it takes vanilla's Realms slot on the title screen for a Nodera Network button, and replaces the multiplayer screen entirely, so there is no Direct Connect and no server list to fall back to. There is a separate feature for playing with an unmodified Minecraft — a tunnel to a host's own LAN world — but it makes the guest a guest, not a peer.
It is not a hosting service, and there is nothing to sign up for. No account, no login, no company holding your world.
It is not finished. The engine, the network stack and both services are proven Minecraft-free.
Wiring them to a real ServerLevel — the live validation lane — is the largest piece still
open, and redstone, fluids, weather, mobs and lighting are not all in that lane yet. There is no
macOS build, and the reason is written down. Every component keeps
a register of its own limitations, each row naming the task that owns it and the exact test that
retires it, and all of them are on this site.
It is not a claim that your world can never go down. It is a claim that the world does not depend on one particular machine. Nobody has to stay, but somebody has to be around: a world whose every peer is offline is a world nobody is holding.
Next
Install the app and the mod, in that order. Then share a world and join one.