Custom Worlds

Server-side mod to create, configure and teleport between multiple custom dimensions at runtime - each world with its own inventory, gamemode, difficulty, gamerules and worldborder. All via simple /cw commands. **Vanilla clients can connect and use /cw tp - no client install needed.** Active Versions: 1.21.1 (NeoForge / Fabric) # See it in action  # Features * **Runtime dimension creation** - `NORMAL`, `FLAT`, `NETHER` or `END` generation, with optional seed. * **Per-world isolated state** - every dim can have its own: * Default gamemode (applied on arrival) * Inventory pool (shared with other "shared" worlds, or fully isolated) * Gamerule overrides (with `reset` to revert) * Difficulty (custom dims only) * Worldborder (full `/worldborder` feature parity) * Public flag - let non-OP players teleport there * **Smart teleport** - remembers each player's last position in every dim; safe-spawn detection on first visit (including Nether ceiling handling). * **Persistent across restarts** - worlds, configs, player positions, inventories. * **Death respawn** - dying in a custom dim respawns you there (unless your bed is elsewhere). * **Vanilla-client compatible** - no client mod required. * **Deletion safety** - `/cw delete` requires confirmation, wipes files and all related per-player buckets. # Commands All commands hang off `/cw`. Public commands are visible to everyone; admin commands require the configured permission level (OP 4 by default). ## Public * `/cw help` - list commands available to you * `/cw tp ` - teleport (admins: any dim; players: public worlds only) * `/cw list` - list worlds (filtered by permission) ## Admin - world management * `/cw create [seed]` * Type: `NORMAL`, `FLAT`, `NETHER`, `END` * Examples: * `/cw create myworld NORMAL` * `/cw create skyblock FLAT 12345` * `/cw create hellscape NETHER` * `/cw delete ` - confirm within 30 seconds by re-running the same command ## Admin - per-world config (run from inside the dim) * `/cw config` - show the current dimension's full config * `/cw config sharedinventory ` - share inventory with other shared worlds, or use a fully isolated pool * `/cw config gamemode ` - gamemode applied on arrival * `/cw config publicWorld ` - allow non-OP players to `/cw tp` here * `/cw config difficulty ` - per-dim difficulty (custom dims only) * `/cw config worldborder ...` - same arguments as vanilla `/worldborder`, but applied to the current dim: * `set []`, `add []` * `center ` * `damage amount `, `damage buffer ` * `warning distance `, `warning time ` * `get` * `/cw config gamerule [ [|reset]]` * No args: list all rules (overridden ones flagged with `*`) * ``: query * ` `: override the rule for this dim * ` reset`: remove the override, revert to default  # Permissions The OP level required for admin commands is configurable in `config//serverconfig/customworlds-server.toml`: ``` permissionLevel = 4 # 0-4, OP level required for admin commands maxWorlds = 0 # 0 = unlimited; hard cap for /cw create deleteConfirmSeconds = 30 # 5-600 ``` `/cw tp` and `/cw list` always remain available to everyone (filtered by the per-world `publicWorld` flag). # Inventory model Each player has one inventory snapshot per "bucket": * **Shared bucket** - used by every dim where `sharedInventory = true` (the overworld is shared by default). All shared worlds use the same inventory. * **Isolated bucket** - one per dim where `sharedInventory = false`. The dim has its own private inventory pool; you keep your shared inventory intact when you go in and out. Buckets persist on disk and survive restarts. Logging out from an isolated dim snapshots your inventory immediately.  # Storage Saved alongside the world data: | File |Purpose | | ------------------------------------------------------------------------ |------------------------------------------------ | | customworlds.json |List of created worlds | | customworlds_config.json |Per-dim config | | customworlds_positions.json |Per-player, per-dim last positions | | customworlds_inventories/<uuid>/<bucket>.dat |NBT inventory + XP snapshots | | dimensions/customworlds/<name>/ |Standard MC dimension data (chunks, entities, …) | Deleting a world wipes all of the above for that dim. Irreversible. # Compatibilities Custom Worlds is compatible with **Curios API** (NeoForge) & **Trinkets** (Fabric), the inventory will sync when these mods are installed. # Limitations * **`doDaylightCycle` per-dim has no visible effect** - game time is shared with the overworld through `DerivedLevelData`. Day/night follows the overworld. * **Per-dim difficulty** only works on `customworlds:*` dims (it would conflict with vanilla's global difficulty for `minecraft:*` dims). For vanilla dims use `/difficulty`. * **Server restart recommended after `/cw create`** - newly-created worlds run on a fallback tick loop until the next restart, after which they integrate normally. The mod tells you so on creation. * Dynamic dimension registration uses reflection against `MinecraftServer` internals. **Back up your save before updating NeoForge.** # FAQ **Do my players need to install the mod?** No. CustomWorlds is server-side only. Vanilla clients can connect and use `/cw tp` for public worlds. **Are the worlds compatible with vanilla?** Yes. Custom dims reuse the vanilla `OVERWORLD`/`NETHER`/`END` dimension types, so vanilla clients recognize them without extra registry data. **What happens if a player is offline when their world gets deleted?** On reconnect, vanilla falls back to the overworld spawn. They'll arrive with whatever inventory was saved in their player.dat at last logout. **Can I edit the JSON files manually?** Yes - they're plain JSON. The loaders tolerate per-entry malformed data and log which entry was skipped. **Can I get more help about Custom Worlds ?** Sure ! Join our discord at https://discord.gg/XNAeUSYswB