Normcore Multiplayer Networking

Comprehensive reference for Normcore 3 real-time multiplayer networking in Unity. Covers the full API surface, patterns, and WebGL platform specifics.

Docs: https://docs.normcore.io/

When to Use This Skill

• Implementing multiplayer synchronisation with Normcore
• Creating RealtimeModels for custom data sync
• Setting up player controllers, ownership, physics networking
• Configuring rooms, regions, quickmatch
• Building for WebGL (this project's primary target)
• Debugging connection, ownership, or sync issues

Core Concepts

Architecture Layers

Realtime API  →  Bridges Unity scene ↔ datastore (most devs work here)
Room + Datastore API  →  Raw state sync, platform-independent
Transport  →  UDP with fallback, congestion control

MVC pattern: Model = RealtimeModel in datastore, View = GameObjects, Controller = RealtimeComponent scripts.

Supported Primitives (RealtimeModel Fields)

C#: bool, byte, sbyte, short, ushort, int, uint, long, ulong, float, double, string, byte[]

Unity: Color, Vector2, Vector3, Vector4, Quaternion

Collections: RealtimeArray, RealtimeSet, RealtimeDictionary, StringKeyDictionary

Nested models supported — one RealtimeModel can contain another.

Quick Patterns

Player Spawner

using Normal.Realtime;

public class PlayerSpawner : MonoBehaviour
{
    private Realtime _realtime;

    void Awake()
    {
        _realtime = GetComponent<Realtime>();
        _realtime.didConnectToRoom += DidConnectToRoom;
    }

    void DidConnectToRoom(Realtime realtime)
    {
        Realtime.Instantiate("Player", Vector3.zero, Quaternion.identity,
            new Realtime.InstantiateOptions {
                ownedByClient            = true,
                preventOwnershipTakeover = true,
                useInstance              = realtime
            });
    }
}

Ownership Guard

void Update()
{
    if (!_realtimeView.isOwnedLocallyInHierarchy) return;
    // Local player input here
}

Custom Data Sync (Minimal)

[RealtimeModel]
public partial class ScoreModel {
    [RealtimeProperty(1, true, true)] private int _score;
}

public class ScoreSync : RealtimeComponent<ScoreModel> {
    protected override void OnRealtimeModelReplaced(ScoreModel prev, ScoreModel cur) {
        if (prev != null) prev.scoreDidChange -= OnScoreChanged;
        if (cur  != null) cur.scoreDidChange  += OnScoreChanged;
    }
    void OnScoreChanged(ScoreModel m, int score) { /* update UI */ }
    public void AddScore(int amount) { model.score += amount; }
}

Decision Tree

WebGL Callouts

• No code changes needed for WebGL builds — Normcore works out of the box
• Voice chat spatialisation does NOT work on web (FMOD not supported). Audio routes through browser directly.
• Region pinging unavailable in WebGL — use GeoIP distance fallback from GetRegionsListAsync()
• HTTPS required for production deployment with valid cert, WASM + gzip content headers
• Cross-platform: WebGL clients can connect to native clients in the same room
• See references/webgl-platform.md for full details

Prefab Requirements

Runtime-spawned objects must be in Assets/Resources/ (or use Addressables / custom RealtimePrefabLoadDelegate):

Assets/Resources/
├── Player.prefab        ← RealtimeView on root
├── Projectile.prefab
└── NetworkedPickup.prefab

References

• Realtime API — Realtime, RealtimeView, RealtimeComponent, RealtimeTransform
• Room + Datastore API — Room, Datastore, RealtimeModel, collections, ownership
• Synchronising Custom Data — Full model/component guide
• Networking Patterns — Player controllers, physics, RPC events, prefab pooling
• WebGL Platform — WebGL config, limitations, React integration
• Configuration & Ops — Regions, quickmatch, disconnect events, auto-reconnect