RoR2ItemSync

A Risk of Rain 2 mod that broadcasts your run data over WebSocket, enabling stream overlays and companion apps to display your game state in real time.

What it syncs

• Multiplayer - data for all players in the lobby, selectable by companion apps
• Inventory - all items and equipment with names, counts, and tiers
• Player stats - health, damage, attack speed, crit, move speed, armor, regen, shield, level
• World state - remaining chests, shops, equipment barrels, printers, ground items, command essences
• Run info - survivor name, stage number, stage name, difficulty, active artifacts

How it works

The mod runs a WebSocket server on port 11420. Any client on the local network can connect to receive JSON updates roughly once per second. The mod also broadcasts a UDP discovery beacon on port 11421 so companion apps can find the server automatically.

For overlay/app developers

Connect to ws://<host-ip>:11420/ to receive messages:

inventory_update

Sent every second while a run is active. Contains the full game state snapshot.

run_ended

Sent when the run ends (death, victory, or quit).

request_challenges (client → server)

Sent by a client to request the current challenge/achievement list. Send this on connect (or whenever the client wants a refresh) — the server does not push challenges automatically.

{ "type": "request_challenges" }

challenges (server → requesting client)

Reply to request_challenges. Sent only to the requesting session, not broadcast.

{
  "type": "challenges",
  "challenges": [
    { "id": "...", "name": "...", "description": "...", "unlocked": true }
  ]
}

Auto-discovery

The mod sends a UDP multicast/broadcast beacon every 2 seconds:

ROR2SYNC:<ip>:<port>:<version>

It also responds to DISCOVER UDP packets on port 11421.

Requirements

• BepInExPack
• HookGenPatcher

Both are installed automatically when using r2modman or Thunderstore Mod Manager.

Installation

1. Install via r2modman or Thunderstore Mod Manager (recommended), or
2. Manually place RoR2ItemSync.dll in your BepInEx/plugins folder (ensure the requirements above are installed)

Configuration

No configuration needed. The mod runs automatically when the game starts.