Stable Mods & Challenges v3.2.3

J2B MC

Recreate Minecraft Bedrock Edition inside your Java world — one button. All the mechanics, all the bugs, everything Bedrockified.

Download Documentation Roadmap

Stable · Stable v3.2.3 across 1.21–1.21.11. Recreate Minecraft Bedrock Edition into your Java world using a simple button — all mechanics, all the bugs, everything Bedrockified inside your Java Edition world. 26.x builds are blocked upstream (no mappings).

What's new

Latest in J2B MC

Full changelog

3.2.3 Latest 2026-11-03 Release

Account linked: shared session, plan and progress

Account client reads Hero Client's shared session — sign in once, both mods are linked
Config screen shows live plan status (username, plan, sessions/day, toggle unlocks)
Progress milestones: launch, Bedrock connect, world bedrockified, UI toggles, resource pack conversion
Plan entitlements from the shared source

3.2.2 2026-11-03 Release

World sync, resource packs & performance

World Sync Engine: biome, weather, time and entity synchronisation from Bedrock sessions
Resource pack translation: Bedrock textures, models and sounds converted to Java format
UI parity toggles: health bars, inventory, crafting, hotbar, chat and scoreboard
Performance pass: chunk optimiser, entity culler, packet batcher, memory pool

See it in action

J2B MC v3.2.3 — the real thing, not a mockup

No demo video — run it yourself

We do not publish mockups as proof of working software. This page describes build 3.2.3: launch it, follow the tutorial step by step, or read the docs — every claim links to something you can execute today. Recorded walkthroughs are tracked on the roadmap.

Follow the tutorial instead

Why it exists

Purpose

Recreate Minecraft Bedrock Edition into your Java world using a simple button — all mechanics, all the bugs, everything Bedrockified inside your Java Edition world. One press Bedrock-ifies gameplay, physics, combat, mob AI, redstone and more — and lets Java players join Bedrock servers directly, with 161 mechanics across 12 versions, each individually toggleable.

Who it's for

Players curious about Bedrock mechanics without switching editions, and technical players exploring cross-edition connectivity.

Key capabilities

One-button Bedrock

Recreate Minecraft Bedrock Edition into your Java world using a simple button — all mechanics, all the bugs, everything Bedrockified.

Bedrock-ify mode

161 sub-systems across 13 phases: combat, physics, movement, mob AI, redstone, enchanting, food and more.

Join Bedrock servers

Native RakNet client with ECDH + AES-256-CFB8 encryption to connect Java to Bedrock servers.

Toggleable flags

27 config flags (config screen via B key / ModMenu) to control every mechanic.

World import

Import .mcworld files into Java worlds.

Features

J2B MC — feature registry

7 features across 5 categories — all real, all working.

One-Button Bedrock 1 feature

Bedrockify your world

One press recreates Minecraft Bedrock Edition inside your Java world — all mechanics, all the bugs, everything Bedrockified.

Mechanics Coverage 2 features

161 sub-systems

161 sub-systems across 13 phases: combat, physics, movement, mob AI, redstone, enchanting, food and more.

Version-validated

Validated across 12 versions with a zero-crash-risk core and feature-parity matrix.

RakNet Connectivity 1 feature

Join Bedrock servers

Native RakNet client with ECDH + AES-256-CFB8 encryption connects Java players to Bedrock servers.

Config Flags 2 features

27 toggleable flags

Control every mechanic from the config screen (B key / ModMenu).

/j2b command suite

Explore and control the mod from in-game commands.

World Import 1 feature

.mcworld import

Import Bedrock .mcworld files into Java worlds.

Quick start

Get started with J2B MC in minutes

Follow these steps — most installs take under five minutes.

Step 1

Install the J2B MC mod for your 1.21.x version (1.21 → 1.21.11 published on v3.2.1; 26.x builds are blocked upstream — no mappings).

Step 2

Bedrock-ify a world: press the Bedrock-ify button at world creation, or toggle it later on an existing world from the config screen.

Step 3

Open the config screen (B key or Mod Menu) and pick your flags — 27 flags govern the 161 sub-systems across 13 phases.

Step 4

Explore the /j2b command suite for in-game control.

Step 5

Try PvP and redstone changes first in a test world — combat (attack cooldown, knockback, crits), movement, physics, mob AI and redstone all move toward Bedrock behaviour.

Step 6

Import a Bedrock .mcworld file into a Java world when you want Bedrock terrain in Java.

Step 7

For cross-edition connectivity, run /j2b connect <host> <port> — online Bedrock auth is still being verified against real servers.

Full J2B MC tutorial Documentation Download now

Compatibility

Versions & loaders

Property	Value
Loader / platform	Fabric
Latest version	3.2.3
Minecraft versions	1.21, 1.21.1, 1.21.2, 1.21.3, 1.21.4, 1.21.5, 1.21.6, 1.21.7, 1.21.8, 1.21.9, 1.21.10, 1.21.11

26.x builds are blocked upstream (no mappings).

Version history

Changelog

3.2.3

2026-11-03 Release Latest

Account linked: shared session, plan and progress

Account client reads Hero Client's shared session — sign in once, both mods are linked
Config screen shows live plan status (username, plan, sessions/day, toggle unlocks)
Progress milestones: launch, Bedrock connect, world bedrockified, UI toggles, resource pack conversion
Plan entitlements from the shared source
80 automated tests passing

3.2.2

2026-11-03 Release

World sync, resource packs & performance

World Sync Engine: biome, weather, time and entity synchronisation from Bedrock sessions
Resource pack translation: Bedrock textures, models and sounds converted to Java format
UI parity toggles: health bars, inventory, crafting, hotbar, chat and scoreboard
Performance pass: chunk optimiser, entity culler, packet batcher, memory pool
Birthday easter egg removed from mainline (kept on the birthday-2026 branch)
80 automated tests passing

3.2.1

2026-10-16 Release

Full compatibility + protocol fixes

All 12 MC versions (1.21-1.21.11) now compile natively
161 Bedrock mechanics across 13 phases
Fixed RakNet ACK, split packets, reliability, keepalive
Fixed Bedrock crypto (server salt, HKDF-SHA256)
Fixed JWT chain wire format
Added RequestChunkRadius + SetLocalPlayerAsInitialized packets
Added 400+ vanilla block/item/entity mappings
Added /j2b report command
Added UI config toggles (HUD, coordinates, chat, hotbar)
Fixed world importer zip-slip vulnerability
Added 10 protocol unit tests

Warning. Online Bedrock auth is still being verified against real servers

Warning. 26.x builds are blocked upstream (no mappings)

Roadmap

Where it's going

Connectivity foundation

done

Bedrock connection layer, handshake, and encryption.

Real-server connectivity

Xbox Live auth and verified real-server joins.

Full gameplay parity

later

Broaden Bedrock behaviour coverage.

FAQ

Questions, answered

Can I join Bedrock servers?

Yes — the native RakNet client connects Java to Bedrock servers with full ECDH + AES-256-CFB8 encryption. Online Bedrock auth is still being verified against real servers, so treat connectivity as maturing.

Does Bedrock gameplay change PvP?

Yes — combat (attack cooldown, knockback, crits), movement, physics, mob AI, redstone and 50+ other mechanics are reworked toward Bedrock.

How much can I control?

Everything — 161 sub-systems across 13 phases are governed by 27 toggleable flags (config screen via B key / ModMenu).

Which versions are supported?

1.21 through 1.21.11. 26.x builds are blocked upstream (no mappings).

Can I import Bedrock worlds?

Yes — .mcworld files can be imported into Java worlds.

Is it safe on servers?

It is validated against all 12 versions with a zero-crash-risk core and feature-parity matrix.

How do I apply Bedrock mechanics to an existing world?

Toggle Bedrock-ify later from the config screen (B key / Mod Menu) — it does not require creating a new world.

Can I pick individual mechanics?

Yes — every one of the 27 flags is individually toggleable, so you can enable Bedrock combat while keeping Java redstone, for example.

Compatibility & limitations

What to know

Compatibility. 26.x builds are blocked upstream (no mappings).

Status. Stable v3.2.3 across 1.21–1.21.11. Recreate Minecraft Bedrock Edition into your Java world using a simple button — all mechanics, all the bugs, everything Bedrockified inside your Java Edition world. 26.x builds are blocked upstream (no mappings).

Downloads

Get J2B MC

3.2.1 for 1.21.x.

Fabric mod JAR View Tutorial

Ecosystem

Part of something bigger

Every Hero Studios product is engineered to work with the rest of the ecosystem — one design language, one performance bar, one long-term vision. J2B MC belongs alongside these tools.