aa71e76eb9
- Add date_added to all 950+ skills for complete tracking - Update version to 6.5.0 in package.json and README - Regenerate all indexes and catalog - Sync all generated files Features from merged PR #150: - Stars/Upvotes system for community-driven discovery - Auto-update mechanism via START_APP.bat - Interactive Prompt Builder - Date tracking badges - Smart auto-categorization All skills validated and indexed. Made-with: Cursor
128 lines
3.0 KiB
Markdown
128 lines
3.0 KiB
Markdown
---
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name: godot-4-migration
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description: "Specialized guide for migrating Godot 3.x projects to Godot 4 (GDScript 2.0), covering syntax changes, Tweens, and exports."
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risk: safe
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source: community
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date_added: "2026-02-27"
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---
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# Godot 4 Migration Guide
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## Overview
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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.
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## When to Use This Skill
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- Use when porting a Godot 3 project to Godot 4.
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- Use when encountering syntax errors after upgrading.
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- Use when replacing deprecated nodes (like `Tween` node vs `create_tween`).
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- Use when updating `export` variables to `@export` annotations.
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## Key Changes
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### 1. Annotations (`@`)
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Godot 4 uses `@` for keywords that modify behavior.
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- `export var x` -> `@export var x`
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- `onready var y` -> `@onready var y`
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- `tool` -> `@tool` (at top of file)
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### 2. Setters and Getters
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Properties now define setters/getters inline.
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**Godot 3:**
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```gdscript
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var health setget set_health, get_health
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func set_health(value):
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health = value
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```
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**Godot 4:**
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```gdscript
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var health: int:
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set(value):
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health = value
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emit_signal("health_changed", health)
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get:
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return health
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```
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### 3. Tween System
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The `Tween` node is deprecated. Use `create_tween()` in code.
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**Godot 3:**
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```gdscript
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$Tween.interpolate_property(...)
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$Tween.start()
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```
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**Godot 4:**
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```gdscript
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var tween = create_tween()
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tween.tween_property($Sprite, "position", Vector2(100, 100), 1.0)
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tween.parallel().tween_property($Sprite, "modulate:a", 0.0, 1.0)
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```
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### 4. Signal Connections
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String-based connections are discouraged. Use callables.
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**Godot 3:**
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```gdscript
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connect("pressed", self, "_on_pressed")
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```
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**Godot 4:**
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```gdscript
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pressed.connect(_on_pressed)
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```
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## Examples
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### Example 1: Typed Arrays
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GDScript 2.0 supports typed arrays for better performance and type safety.
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```gdscript
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# Godot 3
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var enemies = []
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# Godot 4
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var enemies: Array[Node] = []
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func _ready():
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for child in get_children():
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if child is Enemy:
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enemies.append(child)
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```
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### Example 2: Awaiting Signals (Coroutines)
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`yield` is replaced by `await`.
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**Godot 3:**
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```gdscript
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yield(get_tree().create_timer(1.0), "timeout")
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```
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**Godot 4:**
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```gdscript
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await get_tree().create_timer(1.0).timeout
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```
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## Best Practices
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- ✅ **Do:** Use `@export_range`, `@export_file`, etc., for better inspector UI.
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- ✅ **Do:** Type all variables (`var x: int`) for performance gains in GDScript 2.0.
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- ✅ **Do:** Use `super()` to call parent methods instead of `.function_name()`.
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- ❌ **Don't:** Use string names for signals (`emit_signal("name")`) if you can use the signal object (`name.emit()`).
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## Troubleshooting
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**Problem:** "Identifier 'Tween' is not a valid type."
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**Solution:** `Tween` is now `SceneTreeTween` or just an object returned by `create_tween()`. You rarely type it explicitly, just use `var tween = create_tween()`.
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