Component Lifecycle: Full Callback Order — OnAwake, OnEnabled, OnStart, OnUpdate, OnFixedUpdate, OnDisabled, OnDestroy

Component Lifecycle: Full Callback Order

s&box components have a well-defined lifecycle. Understanding the exact order prevents subtle bugs.

Callback Order

Key Behaviors

• OnAwake is only called if ShouldExecute is true. Components on a PrefabCacheScene never execute. Components on an editor scene only execute if they implement ExecuteInEditor. Components implementing DontExecuteOnServer are skipped on dedicated servers.
• OnStart is deferred — it runs at the start of the next update tick, not immediately when the component is enabled. It is guaranteed to run before OnUpdate or OnFixedUpdate.
• OnEnabled and OnDisabled are guarded against double-firing. The engine tracks _onEnabled internally.
• Interpolation is explicitly disabled during OnAwake, OnEnabled, OnDisabled, and OnStart to prevent transform artifacts when objects are created inside a fixed update context.
• OnDestroy exceptions are caught and logged — they do not propagate.
• After OnDestroy, IsValid returns false because GameObject is set to null.

Action Graph Callbacks

Components also expose Action properties for no-code use:

• OnComponentEnabled, OnComponentStart, OnComponentUpdate, OnComponentFixedUpdate, OnComponentDisabled, OnComponentDestroy

Example

public class MyComponent : Component
{
    protected override void OnAwake()
    {
        // Runs once. Transform interpolation is disabled here.
        Log.Info( "Awake" );
    }

    protected override void OnEnabled()
    {
        // Runs each time we become active.
        Log.Info( "Enabled" );
    }

    protected override void OnStart()
    {
        // Runs once, before first Update.
        Log.Info( "Start" );
    }

    protected override void OnUpdate()
    {
        // Every frame.
    }

    protected override void OnFixedUpdate()
    {
        // Fixed timestep. Time.Delta is the fixed interval.
    }

    protected override void OnDisabled()
    {
        Log.Info( "Disabled" );
    }

    protected override void OnDestroy()
    {
        // After this, IsValid == false.
        Log.Info( "Destroyed" );
    }
}