Porting: Fabric → NeoForge

This document explains the differences between the original Fabric version (Apace100/origins-fabric) and the NeoForge rewrite (IAFEnvoy/Origins-NeoForge). Use it to convert existing data packs, add-ons, or documentation from the Fabric version to the NeoForge version.

info

You can try to use Auto Converter for an automated conversion of your data pack, but be sure to review the output and apply any necessary manual adjustments based on the differences outlined in this guide.

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Data Path Changes

All JSON files moved from custom paths to Vanilla DataPack Registry paths.

Content	Fabric Path	NeoForge Path
Origin	data/<ns>/origins/	data/<ns>/origins/origin/
Power	data/<ns>/powers/	data/<ns>/origins/power/
Layer	data/<ns>/origin_layers/	data/<ns>/origins/layer/
Badge	(not in Fabric)	data/<ns>/origins/badge/
Global Power Set	data/<ns>/global_powers/	data/<ns>/origins/global_powers/

Action: Move files and add registry subfolder (origin/, power/, layer/, badge/).

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Origin JSON Changes

Field	Status	Notes
name	Change to Optional	Use translation key origin.<ns>.<path>.name is more recommended
description	Change to Optional	Use translation key origin.<ns>.<path>.description is more recommended
loading_priority	❌ Removed	Data packs now override by priority naturally
powers	Changed	Now supports #tag references. Prefer #tag over listing individual power IDs
icon	Changed	From Item+Damage+NBT to {"id": "minecraft:feather"}
order	Changed	Default changed from 0 to Integer.MAX_VALUE
impact	Same	0=None, 1=Low, 2=Medium, 3=High
unchoosable	Same
upgrades	Same

Action: Remove name/description/loading_priority from all origin JSONs. Add name/description via language files instead. Update icon to the new {"id": "..."} format. Use #tag references in powers instead of listing each power ID individually whenever possible.

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Layer JSON Changes

Field	Status	Notes
replace	❌ Removed	Use data pack override behavior
name	Change to Optional	Use translation key layer.<ns>.<path>.name is more recommended
missing_name	❌ Removed	Not needed
missing_description	❌ Removed	Not needed
origins	Changed	Now supports #tag references. Prefer #tag over listing individual origin IDs
gui_title.choose_origin	Renamed	Was choose_origin (top-level); now nested under gui_title
gui_title.view_origin	Renamed	Was view_origin (top-level); now nested under gui_title
order	Same
enabled	Same
allow_random	Same
hidden	Same
auto_choose	Same
default_origin	Same
allow_random_unchoosable	Same
exclude_random	Same

Action: Move choose_origin/view_origin under gui_title. Remove replace/name/missing_name/missing_description. Use #tag references in origins instead of listing each origin ID individually whenever possible.

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Power JSON Changes

Field	Status	Notes
hidden	Same
condition	Same	Entity Condition
loading_priority	Same
badges	Same	Supports inline {badge} objects
type	Same	Power type ID

Action: Power JSONs are mostly compatible. Translate power names/descriptions via power.<ns>.<path>.name / .description keys.

origins:multiple — Split into individual files

Fabric's origins:multiple power type (which bundled several sub-powers into one JSON file) does not exist in NeoForge. Each sub-power must be extracted into its own standalone power JSON file.

Fabric	NeoForge
One multiple JSON with nested sub-powers	One file per power, referenced individually
"type": "origins:multiple" with "powers": [...]	Each power gets its own file in data/<ns>/origins/power/

Action: For each entry in the powers list of an origins:multiple, create a separate power JSON file. Reference all the split power IDs in the origin's powers field or a power #tag.

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Removed Condition Types

Fabric Type	Status in NeoForge	Note
origins:command	❌ Removed
origins:entity_group	❌ Removed	1.21.1 no longer has entity groups, use origins:in_tag instead
origins:category (biome)	❌ Removed	1.21.1 no longer has biome categories, use origins:in_tag instead
origins:high_humidity (biome)	❌ Removed	1.21.1 no longer has humidity conditions, use origins:in_tag instead`
origins:owner (bientity)	❌ Removed	Will be added later

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Not Yet Implemented

These features existed in Fabric but are not yet available in NeoForge:

Feature	Status
origins:edible_item power type	❌ Not yet implemented
origins:modify_enchantment_level power type	❌ Not yet implemented

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New Features

Feature	Notes
DataPack Registry System	All Origins JSON uses Vanilla's datapack registry
Power Tags	Reference #tag in origin powers and layer origins
Badge Registry	Badges use Vanilla registry at origins:badge
Inline Badge Definitions	badges in powers can take inline {badge} objects
ColorSettings	red/green/blue/alpha floats + single color hex integer

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Key API Differences

Fabric (Apoli) API	NeoForge API
PowerTypeRegistry	PowerRegistries.POWER_KEY via Registry
OriginsRegistry	OriginRegistries.ORIGIN_KEY
OriginLayerRegistry	LayerRegistries.LAYER_KEY
OriginsAPI	OriginDataHolder.get(entity) as attachment
PowerType interface	Power abstract class with MapCodec
PowerHolderComponent	OriginDataHolder (NeoForge attachment)
PowerTypeRegistry#register	BuiltInRegistries + DeferredRegister pattern

Action: For Java add-ons targeting NeoForge, port from Apoli's PowerTypeRegistry to NeoForge's DeferredRegister<MapCodec<? extends Power>> pattern.

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AI Porting Prompt

When converting Fabric Origins data packs to NeoForge, use this prompt:

You are porting an Origins Fabric data pack to the NeoForge version (IAFEnvoy/Origins-NeoForge).

Changes to apply:
1. Move all JSON files to datapack registry paths:
   - origin JSONs: data/<ns>/origins/ → data/<ns>/origins/origin/
   - power JSONs: data/<ns>/powers/ → data/<ns>/origins/power/
   - layer JSONs: data/<ns>/origin_layers/ → data/<ns>/origins/layer/
2. Remove from Origin JSONs: name, description, loading_priority.
   Add translations to language file: "origin.<ns>.<id>.name" and ".description".
3. Remove from Layer JSONs: replace, name, missing_name, missing_description.
   Move choose_origin/view_origin under a new "gui_title" object.
   Add translations: "layer.<ns>.<id>.name".
   Use #tag references in origins instead of listing individual origin IDs.
4. Update icon format: old "item"/"damage"/"nbt" → new {"id": "minecraft:..."}
   Use #tag references in powers instead of listing individual power IDs.
5. Split any origins:multiple powers into individual power JSON files.
6. Replace removed condition types (command, entity_group, category, high_humidity, owner) with equivalent alternatives or JS scripts.
7. Check the porting guide at porting.md for the full list of differences.