The in-game half of the Runic Gateway bridge for Rust: one Oxide plugin that dials out to a rust-link sidecar and speaks newline-delimited JSON over it.

It is the mirror of RunicGateway/servuo-plugins, which does the same job for Ultima Online — and it inherits that plugin's threading contract wholesale, because the reason for it is the same on both games.

The threading contract

Everything else in this repo depends on these three:

Emit is called from the main thread. It formats nothing, blocks on nothing, and touches no socket. It enqueues and returns. A slow, wedged, or absent sidecar cannot stall the game.
One link thread owns the socket. It connects, drains the queue, and reconnects with backoff. A single writer keeps event ordering intact.
A reader thread parses inbound lines and hands each to the main thread via Interface.Oxide.NextTick. The reader touches no Unity object, no BasePlayer and no ConVar — every one of those is main-thread-only, and reading one from the reader is the kind of bug that presents as a crash somewhere else entirely.

The outbound queue is bounded, drop-oldest. On overflow the oldest record goes and is counted, because telemetry is worth less than the server's memory.

Loopback is the trust boundary

There is no token on the game link. The plugin and the sidecar share a host, and the sidecar binds 127.0.0.1 — that is the authentication. Pointing Host at anything routable puts an unauthenticated command channel on the network.

Installing it

overlay/oxide/plugins/RunicGateway.cs  →  <server>/oxide/plugins/RunicGateway.cs

Oxide compiles and loads it on the write, and writes oxide/config/RunicGateway.json on first load:

{
  "Host": "127.0.0.1",
  "Port": 7799,
  "QueueCap": 5000,
  "ServerId": "main"
}

ServerId is this server's stable identity across wipes and restarts, as the website knows it. It is deliberately not derived from the hostname: an operator renames a server for a season, and the site must not lose its history for it.

That is the developer's loop. An operator uses the installer, which syncs the released overlay tarball and installs the sidecar alongside it.

Prerequisites

The bridge itself needs nothing but Oxide. The features that follow it read four third-party plugins an operator installs from uMod — Clans, Kits, PopupNotifications and ZoneManager. They are listed in overlay.toml so the installer's doctor can report a missing one by name rather than leaving the site quietly short of a feature.

Diagnosing it

rg.link

from the server console or over RCON. It reports the link's own counters:

protocol=1 serverId=main connected=True depth=0 sent=3 dropped=0 received=2
connects=1 writeErrors=0 bootId=boot-20260915T194502Z

This is the first thing to ask for when the website says a server is offline — it separates "the plugin is not loaded", "the plugin cannot reach the sidecar" and "the website cannot reach the sidecar", which look identical from the site.

bootId identifies the server PROCESS, not the plugin load. It is the process start time, so oxide.reload RunicGateway does not change it. That matters more than it looks: the website watches this value to tell a game restart (everything an event put in the world is gone) from a bridge reconnect (nothing is lost), and a plugin reload is the second kind.

The protocol is a contract

ProtocolVersion in the plugin and protocol in overlay.toml must agree with the sidecar's PROTOCOL_VERSION and the module's own constant. The installer refuses to pair an overlay and a sidecar that disagree, so a bump landing in one repo and not the others fails to compose rather than half-deploying.

The canonical spec is docs/rust-link/PROTOCOL.md.

Licence

GPL-3.0-or-later. See LICENSE.md.