Dimension Mod Configurator

Server-side only. No client mod required.

A utility mod for modpack authors and server administrators that lets you control what players can do and what mods can generate structures in specific dimensions, all through config files.

Disclaimer: Yes this Mod was made using AI, as this Description too. You don't like it? You don't need to use it.

What It Does

Player Restrictions

All restrictions are configured in config/dimconfig-server.toml and support both allowlist and denylist modes, wildcard dimension IDs, item/block tags, and optional OP bypass.

Item use blocking Prevent players from using specific items in specific dimensions. Useful for banning mobility items like elytra or rockets in certain worlds.

Block placement blocking Prevent players from placing specific blocks in specific dimensions. Supports tag-based entries (e.g. #minecraft:logs).

Portal travel blocking Block travel between dimension pairs via portals. Configurable per source-destination pair so you can allow entry but prevent exit, or block both ways independently.

Equipment (armor) restrictions Forcibly remove forbidden armor pieces when a player is in a restricted dimension. Useful for banning jetpacks, powered armor, or other equipment in specific worlds. Removed items are dropped at the player's feet. OP bypass is configurable.

/backToSpawn command A dimension-aware "go home" command. Teleports the player to world spawn. Can be restricted to specific dimensions (e.g. only usable from the Nether), supports a configurable countdown before teleporting and a cooldown between uses.

Mod Compatibility

Tempad integration Block the Tempad mod's timedoor teleporter from opening in or targeting restricted dimensions. Supports allowlist or denylist mode.

Create: More Package Couriers integration Restrict cardboard plane delivery to specific dimensions. Separate rules for player-targeting and depot-targeting deliveries.

Worldgen Firewall (`dimfirewall`)

The flagship feature. The firewall intercepts Minecraft's worldgen pipeline at multiple levels and blocks configured mods from generating their structures in the configured dimensions — purely through config, with no need to modify other mods' files or datapacks.

Why It Exists

The primary use case is a modpack running a vanilla-like minecraft:overworld alongside a parallel dimension (e.g. from Parallel Worlds) that should receive all the structure mods. Both dimensions may share the same biome preset, but you want them to behave completely differently. Without the firewall, any mod that adds overworld structures or features will inject into both. The firewall lets you say: "DnT and CTOV generate here, not there."

What It Intercepts

The firewall blocks content at three independent points in the generation pipeline:

Structure placement — prevents blocked mods' structure sets from being considered when a chunk generates
Jigsaw pool elements — filters individual pool pieces during jigsaw assembly, preventing cross-mod contamination even when structure sets are shared
Placed features — cancels feature placement (trees, ores, decorations, etc.) for blocked namespaces on a per-chunk basis
/locate command — suppresses locate results for firewall-blocked structures so players can't find structures that aren't generating

Rule Files

Firewall rules are JSON files placed in config/dimconfig/. The server scans all .json files in that folder on startup and when you run /dimfirewall reload.

Single rule (bare object):

{
  "mode": "denylist",
  "dimensions": ["minecraft:overworld"],
  "sources": [
    { "namespace": "ctov" },
    { "namespace": "tectonic" }
  ]
}

Multiple rules in one file:

{
  "rules": [
    {
      "mode": "denylist",
      "dimensions": ["minecraft:overworld"],
      "sources": [{ "namespace": "ctov" }]
    },
    {
      "mode": "allowlist",
      "dimensions": ["parallelworlds:pw_overworld_*"],
      "sources": [{ "namespace": "ctov" }, { "namespace": "minecraft" }]
    }
  ]
}

Fields:

Field	Description
`mode`	`"allowlist"` — only the listed sources generate in the listed dimensions; everything else is blocked. `"denylist"` — the listed sources are blocked; everything else passes through.
`dimensions`	List of dimension IDs. Supports `` wildcards, e.g. `"parallelworlds:pw_overworld_"`.
`sources`	List of source matchers. `{ "namespace": "modid" }` matches everything from that mod. `{ "structure_set": "modid:name" }` matches a single structure set by ResourceKey and takes priority over namespace wildcards.

Commands

All /dimfirewall subcommands require OP level 2 or higher.

Command	Description
`/dimfirewall snapshot`	Scans all currently loaded dimensions and writes a dated allowlist rule file to `config/dimconfig/`. This captures the current worldgen state.
`/dimfirewall reload`	Re-reads all files in `config/dimconfig/` and rebuilds the firewall rule set immediately, without a full server `/reload`.
`/dimfirewall rules`	Lists all currently loaded firewall rules.
`/dimfirewall inspect <dimension>`	Shows which rules apply to a specific dimension.
`/backToSpawn`	Available to all players (subject to config restrictions). Teleports to world spawn with a countdown and cooldown.

Server Admin Quick Start

Restricting player behavior

Open config/dimconfig-server.toml. Each feature section has an enabled toggle. Entries use "dimension_id|item_or_block_id" format. Wildcards (*) and item tags (#modid:tagname) are supported. Config is hot-reloaded when NeoForge reloads server configs.

Using the worldgen firewall

Typical setup for a modpack with a parallel overworld:

Start the server once with all mods installed but before generating any terrain in your parallel dimension.
Run /dimfirewall snapshot — this writes a JSON rule file to config/dimconfig/ with an allowlist of everything currently in each dimension.
Review the generated file and adjust as needed (e.g. switch from allowlist to denylist, add or remove sources).
Restart the server. The firewall rules are now active.

Adding a rule manually:

Create a .json file in config/dimconfig/ (the filename does not matter), write your rule, and either restart or run /dimfirewall reload.

Checking what's active:

/dimfirewall rules — shows all loaded rules
/dimfirewall inspect minecraft:overworld — shows rules that affect a specific dimension

Important notes:

Structure and feature suppression take effect during chunk generation. They do not retroactively change already-generated chunks.
The firewall operates entirely server-side. Players do not need the mod installed.

Dimension Configurator