/godot-save-load-systems

Migration notes: godot-save-load-systems

Incremental upgrade for topics this skill covers. Apply one hop, stabilize/test, then next. Never skip hops.

If the project is < 4.0, follow godot-version-migration era bridges (legacy → 3→4) until 4.0, then these hops. Official 3→4: Upgrading from Godot 3 to Godot 4.

3.x → 4.0

Official: Upgrading from Godot 3 to Godot 4

• File/Directory → FileAccess/DirAccess (often static APIs).
• ResourceSaver.save argument order swapped (resource, path).
• Time via Time singleton (not OS); JSON helpers differ from 3.x Dictionary.to_json patterns.
• Keep save schema versioning separate from engine hops — still bump save version when fields change.

4.0 → 4.1

Official: Upgrading to Godot 4.1

No skill-relevant breaking changes for this hop.

4.1 → 4.2

Official: Upgrading to Godot 4.2

No skill-relevant breaking changes for this hop.

4.2 → 4.3

Official: Upgrading to Godot 4.3

• Scripted Object / typed Array binary serialization changed — round-trip all save Resource schemas.
• Large PackedByteArray compact storage may not open in older editors — avoid downgrading save files.

4.3 → 4.4

Official: Upgrading to Godot 4.4

• FileAccess.store_var() / store_buffer() return bool — handle write failures; never assume success.
• @export_file Inspector values may store uid:// — resolve UIDs when loading designer-assigned default save paths.
• Curve enforces configured min/max — remapping curves in save-slot metadata may clamp unexpectedly.

4.4 → 4.5

Official: Upgrading to Godot 4.5

• Resource.duplicate(true) deep-copies internal resources only — use duplicate_deep(DEEP_DUPLICATE_ALL) when cloning save templates with external sub-resources.

4.5 → 4.6

Official: Upgrading to Godot 4.6

• TSCN unique node IDs on first 4.6 save — do not key saves on ephemeral node instance ids from .tscn order.

4.6 → 4.7

Official: Upgrading to Godot 4.7

• Packed array element assignment no longer invokes custom setters — typed-array save caches may stop emitting change signals.
• Typed-return overrides must explicitly return — audit save-manager methods with typed returns.