More Furnaces Client Compatibility

By
K9_pos_ela

Restores More Furnaces items in JEI and creative mode, and corrects recipe display with Polymer on Fabric.

# More Furnaces Client Compatibility

See the correct More Furnaces items and crafting ingredients in JEI.

This is an **independent compatibility addon** for [More Furnaces (Polymer)](https://www.curseforge.com/minecraft/mc-mods/more-furnaces-polymer), Polymer and [Just Enough Items](https://www.curseforge.com/minecraft/mc-mods/jei), developed for the Voxy Enhanced modpack on **Minecraft 1.21.11 / Fabric**. It is not a replacement for these mods or an official release by their authors.

## What it fixes

- Recovers the **four furnaces and eight upgrade modules** in JEI without adding duplicate item identities.

- Makes the original items and their Polymer network representations match during JEI identity lookups.

- Corrects crafting recipe display that could otherwise show a barrier instead of the previous-tier furnace, or sticks instead of module ingredients.

- Adds a fallback **More Furnaces** creative tab only when Polymer's synchronized tab is missing or empty. The fallback stays hidden when the original tab works.

- Reads the host's active More Furnaces crafting recipes and synchronizes them to supported clients on join and after a successful data reload. Disabled recipes are not advertised, and cached recipe data is cleared on disconnect.

The addon does **not** add new furnace tiers or change smelting speed, fuel use, crafting progression, block registries or world generation. It changes how existing items and recipes are presented. Recipes from other namespaces are left alone; no fixed copies of upstream recipe JSON files are bundled.

## Exact supported setup

- **Minecraft 1.21.11**, **Fabric Loader 0.18.4+**, Java **21+**.

- **More Furnaces (Polymer) 1.2.1+1.21.11**.

- **JEI 27.x**; development checks used **27.48.0.106**.

- **Polymer Core 0.15.1+1.21.11**; this is already bundled inside the tested More Furnaces JAR. Other 0.15.x versions are allowed by metadata but not individually verified.

- **Fabric API** for Minecraft 1.21.11; development checks used **0.141.6+1.21.11**.

The Voxy Enhanced reference setup uses Fabric Loader **0.20.1** and Java **25**. This addon accesses version-specific Polymer/JEI internals; future or different versions may require an update.

## Installation — host and clients

Put this JAR in `mods` together with its required mods. In singleplayer, the host is the integrated server in the same client installation.

**For the complete beta.3 recipe correction in multiplayer, install the matching addon on both the host/server and the clients that use the fix.** A client-only installation cannot reconstruct the authoritative recipes by itself. Extra recipe data is sent only to clients that announce support for the addon channel.

This JAR declares a dependency on JEI in both environments. If using a dedicated server, satisfy the declared dependencies as well; a dedicated-server connection was not independently tested during publication preparation. Do not treat this as a universally verified server-only fix.

Do not install beta.1, beta.2 and beta.3 together. Only one JAR with mod ID `morefurnaces_client_compat` may be installed.

## Checking the result

Search for the furnaces in JEI and press **R**. The gold furnace should use the iron furnace, diamond should use gold, and netherite should use diamond in the appropriate recipe. Higher-tier modules should show the previous-tier modules as their ingredients, not placeholder sticks. Check the creative tab and ordinary crafting too.

The source-modpack maintainer confirmed that the beta.3 ingredients displayed correctly. Automated isolated checks also passed for all **12 original crafting recipes** through the real recipe/payload codecs, the actual JEI mixins, item identities, disabled recipes, unrelated recipes and disconnect cleanup. These checks do not establish compatibility with every modpack or a fresh dedicated-server multiplayer session. No new gameplay code was built for this publication package.

## Credits and license

- Original compatibility code: **K9 / Chris Heverton**, for **Voxy Enhanced**.

- More Furnaces (Polymer): **JongWasTaken** — [official project](https://www.curseforge.com/minecraft/mc-mods/more-furnaces-polymer).

- Polymer: **Patbox and contributors** — [official project](https://www.curseforge.com/minecraft/mc-mods/polymer).

- Just Enough Items: **mezz and contributors** — [official project](https://www.curseforge.com/minecraft/mc-mods/jei).

- Fabric API and Minecraft remain separate dependencies with their respective authorship and licenses.

This is original integration code, not a fork redistributing the upstream mods. Their classes, textures and recipe files are **not bundled** in this addon. The addon's existing **Custom License / All Rights Reserved** is preserved in `LICENSE.txt`; the MIT/GPL or other licenses of upstream projects do not relicense this original compatibility code. Official submission is made by its copyright holder; third parties are not granted standalone redistribution or modified-publication rights by this notice.

Not endorsed by or affiliated with the upstream mod authors, Mojang or Microsoft.

**Artwork disclosure:** the project avatar is an original AI-generated illustration representing recipe compatibility. It is not a game screenshot, an actual furnace texture, or a demonstration of a particular crafting recipe.