Synchro

Synchro turns multiplayer survival into one shared player state. Inventories, armor, health, hunger, effects, XP, advancements, ender chests, fire state, sleep, and death can all be synchronized so a group plays as one combined character.

If you want a co-op challenge where every action matters for everyone, Synchro is built for that exact server style.

Highlights

• Shared inventory, armor, ender chest, advancements, health, hunger, saturation, XP, and potion effects
• One-player sleep for skipping night without requiring the whole group to enter beds
• Synchronized fire ticks, death, respawn handling, and post-death inventory state
• Race-condition protection with versioned shared state and delayed-apply guards
• Safer inventory handling for crafting, furnace extraction, hoppers, pickups, drops, buckets, vehicles, item frames, and /give
• Per-module config.yml toggles with /synchro reload
• Admin tools for force sync, restore, debug logging, status, and version checks
• Optional update notifications from Modrinth and GitHub for players with admin permission
• Folia-aware scheduling paths with Bukkit/Paper fallback

Commands

• /synchro enable
• /synchro disable
• /synchro sync [module]
• /synchro status
• /synchro reload
• /synchro restore
• /synchro debug <on|off>
• /synchro version

Supported sync modules are all, inventory, armor, effects, potion-effects, health, hunger, experience, xp, ender-chest, and fire-ticks.

Permissions

• synchro.admin - Use Synchro admin commands and receive update notifications

Configuration

Every module is enabled by default. Set a module to false in config.yml and run /synchro reload to disable only that part of synchronization.

sync:
  inventory: true
  armor: true
  potion-effects: true
  health: true
  hunger: true
  experience: true
  death: true
  ender-chest: true
  advancements: true
  one-player-sleep: true
  fire-ticks: true

debug:
  enabled: false

update-checker:
  enabled: true
  check-interval-minutes: 60
  notify-permission: synchro.admin
  modrinth-project: "I0rM9fEI"
  github-repo: "St1ch/Synchro"

Typical Workflow

1. Install Synchro and start the server once to generate config.yml.
2. Join with two or more players and run /synchro status.
3. Use /synchro sync to initialize the shared state if needed.
4. Adjust module toggles in config.yml for the type of co-op challenge you want.
5. Run /synchro reload after config changes.
6. Use /synchro debug on while testing edge cases, then turn it off for normal play.

Update Notifications

When a newer version is found, players with synchro.admin are notified when they join. Modrinth checks use project I0rM9fEI, and GitHub release checks use St1ch/Synchro.

The checker is cached by update-checker.check-interval-minutes, so it does not call remote APIs on every join.

API Usage

Other plugins can use Synchro's API:

import org.redstone.SynchroAPI;

if (SynchroAPI.isSyncEnabled()) {
    // Do something.
}
SynchroAPI.setSyncEnabled(false);
SynchroAPI.manualSync();

Development

Build the plugin with:

.\gradlew.bat build

The built jar will be available in build/libs.

Compatibility

• Minecraft: 1.18 to 1.21.x
• Cores: Bukkit, Spigot, Paper, Folia
• Java: 17

Notes

• Synchro is designed around shared survival state, not per-player independent inventories.
• The update checker uses Modrinth and GitHub public APIs and only notifies players with the configured permission.
• Some complex inventory behavior depends on server tick timing; debug logging can help diagnose unusual plugin-stack interactions.

License

This project is distributed under the MIT License.