A lightweight, zero-dependency dependency injection container for Unity.
Part of the Unity Nexus plugin family.

Installation

Add via Unity Package Manager using the git URL:

https://github.com/arijeetbaruah/Unity-Nexus.git

Quick Start

1. Create an Installer

using UnityNexus.DI;
 
public class GameInstaller : NexusInstaller
{
    protected override void InstallBindings(DependencyContainer container)
    {
        container.BindInstance(new AudioService());
        container.BindSingleton<IPlayerService>(() => new PlayerService());
        container.BindTransient<IEnemyFactory>(() => new EnemyFactory());
    }
}

Attach GameInstaller to a GameObject in your scene. It runs on Awake before everything else — set its Script Execution Order accordingly.

2. Implement IInjectable

using UnityNexus.DI;
using UnityEngine;
 
public class LevelingService : MonoBehaviour, IInjectable
{
    private IPlayerService _playerService;
 
    public void Inject(DependencyContainer container)
    {
        _playerService = container.Resolve<IPlayerService>();
    }
}

NexusInstaller automatically finds all IInjectable MonoBehaviours in the scene and calls Inject after bindings are registered.

Binding Types

Method	Behaviour
BindInstance<T>(instance)	Registers a pre-existing object as a singleton
BindSingleton<T>(factory)	Creates once on first resolve, cached forever
BindTransient<T>(factory)	Creates a new instance on every resolve

Resolving

// Direct resolve — throws BindingNotFoundException if missing
var service = container.Resolve<IPlayerService>();
 
// Safe resolve — returns false if missing
if (container.TryResolve<IPlayerService>(out var service))
{
    // use service
}
 
// Check before resolving
if (container.HasBinding<IPlayerService>())
{
    // ...
}

Requirements

Unity 2021.3+
.NET Standard 2.1