CrossbowSaveArrow

Per-crossbow ammo storage for Hytale. Each crossbow remembers its loaded arrows independently.

The Problem

In vanilla Hytale, arrows are lost when you switch away from a crossbow. If you loaded 4 arrows and switch to a sword, those arrows vanish. This happens because ammo is stored as an entity stat (on the player), not on the item itself. When the weapon modifier is removed on switch, clamp(ammo, 0, 0) = 0 — arrows gone forever.

Features

Arrows persist on weapon switch — each crossbow stores its own arrow count in ItemStack metadata
Deferred arrow consumption — arrows are removed from inventory only AFTER ammo actually increases, preventing loss on interrupted reload
No arrow duplication — vanilla SwapFrom arrow return is blocked
UUID tracking — each crossbow gets a unique ID for reliable identification
Persistent storage — ammo is saved when you: switch weapons, drop, store in chest, trade, relog
Zero performance overhead — event-based architecture, no tick polling

Architecture

4 Mixins injected via Hyxin:

Mixin	Target	Method	Purpose
`StatModifiersManagerMixin`	`StatModifiersManager`	`@Inject RETURN recalculateEntityStatModifiers`	Populate entity map, assign UUID, restore ammo from metadata
`EntityStatMapMixin`	`EntityStatMap`	`@Overwrite addStatValue`	Deferred arrow removal after ammo increase, write metadata on any ammo change
`ModifyInventoryInteractionMixin`	`ModifyInventoryInteraction`	`@Redirect x2 firstRun`	Defer arrow removal to ThreadLocal, block arrow return on SwapFrom
`ItemStackMixin`	`ItemStack`	`@Overwrite isEquivalentType`	Ignore LoadedAmmo/CrossbowUUID in metadata comparison to prevent cancelOnItemChange

Cross-classloader shared state via System.getProperties() (Mixin classloader cannot see non-mixin classes from the same JAR).

ItemStack metadata (source of truth)
+-- LoadedAmmo: float    -- current arrow count
+-- CrossbowUUID: string -- unique crossbow identifier

Requirements

Hyxin — Mixin loader for Hytale
- CurseForge
- GitHub

Installation

Single Player / Client-Hosted Server

Download Hyxin.jar and place it in:
```
UserData/EarlyPlugins/
```
Download CrossbowSaveArrow-x.x.x.jar and place it in your world save folder:
```
UserData/Saves/<YourWorldName>/earlyplugins
```
(Create the earlyplugins file if it doesn't exist — it's a ZIP archive containing the jar)
Launch the game and load the world

Linux users: The folder must be named exactly earlyplugins (lowercase). Linux is case-sensitive, so EarlyPlugins won't work.

Dedicated Server

Download Hyxin.jar and place it in:
```
<ServerRoot>/earlyplugins/
```
Download CrossbowSaveArrow-x.x.x.jar and place it in:
```
<ServerRoot>/earlyplugins/
```

Linux users: The folder must be named exactly earlyplugins (lowercase). Linux is case-sensitive.

Start the server

Changelog

v0.0.3

Universal weapon detection — no longer relies on item name.

Changed:

All 4 mixins no longer check itemId.contains("Crossbow") to identify crossbows
EntityStatMapMixin — writes LoadedAmmo metadata on any ammo stat change, regardless of item name
StatModifiersManagerMixin — detects weapons by presence of LoadedAmmo metadata instead of name
ModifyInventoryInteractionMixin — checks for LoadedAmmo/CrossbowUUID metadata on held item instead of name
ItemStackMixin — checks for our metadata keys in BsonDocument instead of item name

Fixed:

Ammo loss on swap with modded crossbows that don't have "Crossbow" in their item ID (e.g. MB crossbows with IDs like MasBallestas_Hierro)

v0.0.2

Complete rewrite of the ammo storage system. 2 mixins -> 4 mixins.

New:

EntityStatMapMixin — overwrites addStatValue() to consume arrows AFTER ammo increases (deferred removal). Prevents arrow loss on interrupted reload. Writes ammo to crossbow metadata on every change (reload/shot)
ItemStackMixin — overwrites isEquivalentType() to ignore LoadedAmmo and CrossbowUUID metadata keys. Prevents cancelOnItemChange from breaking reload chains when metadata is updated
UUID assigned to each crossbow for reliable tracking
Hyxin detection check on startup with SEVERE error log if not found
Cross-classloader state via System.getProperties() (ThreadLocal + WeakHashMap)

Changed:

StatModifiersManagerMixin — removed HEAD inject and all WeakHashMap tracking (lastCrossbowSlot, lastCrossbowAmmo, hasRestored). Now only uses RETURN inject. Always restores ammo from metadata (not only when currentAmmo == 0)
ModifyInventoryInteractionMixin — added second @Redirect for removeItemStack to defer arrow removal instead of letting vanilla remove arrows before ammo increases
Removed all debug LOGGER.info() calls for production

Fixed:

Arrow loss on interrupted reload (arrows were removed before ammo increased)
Ammo not restoring when switching between two crossbows (old code required currentAmmo == 0)
Ammo desync on relog (entity stat loaded from disk, not 0, restore skipped)
Reload chain breaking when metadata was written to active hotbar slot (triggered cancelOnItemChange)

v1.0.0

Initial release. 2 mixins: StatModifiersManagerMixin (HEAD+RETURN), ModifyInventoryInteractionMixin (1 redirect).

Compatibility

Works with vanilla crossbows and any modded crossbows that use the standard ammo stat system
Compatible with other mods that don't modify crossbow ammo behavior

Credits

Author: Morgott
Mixin Framework: Hyxin by Jenya705 — CurseForge | GitHub

Crossbow Save Arrow