godot-4-migration

name	godot-4-migration
description	Specialized guide for migrating Godot 3.x projects to Godot 4 (GDScript 2.0), covering syntax changes, Tweens, and exports.
type	skill
created	2026-02-27T00:00:00.000Z
domain	design-creative
category	3d-animation
risk	safe
source	community
tags	["skill","design-creative","3d-animation","godot","migration"]

Godot 4 Migration Guide

Overview

A critical guide for developers transitioning from Godot 3.x to Godot 4. This skill focuses on the major syntax changes in GDScript 2.0, the new Tween system, and export annotation updates.

When to Use This Skill

• Use when porting a Godot 3 project to Godot 4.
• Use when encountering syntax errors after upgrading.
• Use when replacing deprecated nodes (like Tween node vs create_tween).
• Use when updating export variables to @export annotations.

Key Changes

1. Annotations (@)

Godot 4 uses @ for keywords that modify behavior.

• export var x -> @export var x
• onready var y -> @onready var y
• tool -> @tool (at top of file)

2. Setters and Getters

Properties now define setters/getters inline.

Godot 3:

var health setget set_health, get_health

func set_health(value):
    health = value

Godot 4:

var health: int:
    set(value):
        health = value
        emit_signal("health_changed", health)
    get:
        return health

3. Tween System

The Tween node is deprecated. Use create_tween() in code.

Godot 3:

$Tween.interpolate_property(...)
$Tween.start()

Godot 4:

var tween = create_tween()
tween.tween_property($Sprite, "position", Vector2(100, 100), 1.0)
tween.parallel().tween_property($Sprite, "modulate:a", 0.0, 1.0)

4. Signal Connections

String-based connections are discouraged. Use callables.

Godot 3:

connect("pressed", self, "_on_pressed")

Godot 4:

pressed.connect(_on_pressed)

Examples

Example 1: Typed Arrays