Docs/Networking

Networked Variables

Auto-synced variables.

13 min read Advanced Updated 2026-07-01 v2.0 ~38 min to complete

Introduction

Auto-synced variables. This page provides a complete guide to networked variables in Appley, covering everything from setup to advanced techniques.

Networking is a core area of Appley. Understanding networked variables will help you build better games and use the platform more effectively. This documentation is designed for advanced level users.

Requirements

Before working with networked variables, ensure you have the following:

A Studio plan subscription (required for multiplayer)
Understanding of client-server architecture
An Appley project with multiplayer scenes
Knowledge of sync and RPC concepts

Estimated Completion Time

This guide takes approximately 38 minutes to complete. The estimated reading time is 13 minutes. Difficulty level: Advanced.

Step-by-Step Guide

Follow these steps to work with networked variables in your Appley project:

Enable multiplayer

In project settings, enable multiplayer networking for networked variables.

Set up the lobby

Create a lobby system with room codes and player limits.

Define networked state

Mark variables as networked to auto-sync across clients.

Implement RPCs

Use network.rpc() for remote procedure calls between clients and host.

Test multiplayer

Open the game in two browser tabs to test client-host communication.

FluxScript Example

Below is an Appley Scripting (Flux Scripting) code example demonstrating networked variables:

Networked Variables — Appley Scripting

// Networking — Networked Variables
on start {
  if network.isHost {
    network.spawn("enemy", vec3(0, 0, 10))
  }
}

on playerJoined(player) {
  ui.toast(player.name + " joined!")
  network.sync("scoreboard", scoreboard)
}

networked score = 0

on update(dt) {
  if network.isLocalPlayer {
    if input("w") player.move(forward, dt)
    if input("f") {
      network.rpc("fireWeapon", { pos: player.position })
    }
  }
}

on rpc("fireWeapon", data) {
  effects.spawn("muzzle_flash", data.pos)
  audio.play("shoot")
}

Node Script Example

The same logic can be implemented using Node Scripting. Here is the equivalent node graph:

Networked Variables — Node Graph

[On Start] ──► [Branch: isHost] ──► [Spawn: enemy]

[On Player Joined] ──► [Toast: name + " joined"]
                    ──► [Sync: scoreboard]

[On Update] ──► [Branch: isLocalPlayer]
            ──► [Input "f"] ──► [RPC: "fireWeapon"]

Interchangeable Systems

FluxScript and Node Scripting compile to the same runtime. You can mix both in a single project — use whichever is best for each task.

Common Mistakes

Avoid these frequent mistakes when working with networked variables:

Trusting client-side data

Validate all client input on the host before applying.

Syncing too many variables

Only sync essential state; use RPCs for events.

Not handling player disconnection

Clean up objects and state when a player leaves.

Using large networked payloads

Keep sync data small — send IDs, not full objects.

Troubleshooting

If you encounter issues with networked variables, try these solutions:

Players cannot connect

Check that the host is running. Verify room codes. Check firewall settings.

High latency and lag

Use interpolation for remote positions. Implement client-side prediction.

State desync between clients

Ensure only the host modifies authoritative state. Use networked variables.

Players see different game states

Implement host-authoritative logic. Validate state changes on host.

Performance Tips

Optimize your use of networked variables with these performance tips:

Use host-authoritative architecture — the host validates all game-critical actions.
Implement client-side prediction for responsive player movement.
Use interpolation for remote entities to smooth over network jitter.
Send only essential data — use IDs and enums, not full strings.

Explore these related documentation pages:

State Synchronization

Networking

Introduction to Appley

Getting Started