Server Guide

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Running Hempdustry 2 on a multiplayer server: installing it, the config file, applying changes, ready-made presets, what survives a restart, and updating safely. Written for server owners. Every config key is explained on Configuration, and the one command on Commands.

On this page: Install · Dedicated-server notes · The config file · Applying changes · Presets · What survives a logout or a restart · In multiplayer · Performance · Updating and upgrading worlds · Reporting bugs

Install

The server and every player need the mod, the same jar on both sides. There is no server-only or client-only mode.

	Fabric	NeoForge
Minecraft 26.3	Fabric Loader 0.20.1+ and Fabric API 0.165.0+26.3 or newer hempdustry-fabric-2.1.0+26.3.jar	NeoForge 26.3.0.101+ hempdustry-neoforge-2.1.0+26.3.jar
Minecraft 26.2	Fabric Loader 0.20.1+ and Fabric API 0.161.0+26.2 or newer hempdustry-fabric-2.1.0+26.2.jar	NeoForge 26.2.0.93+ hempdustry-neoforge-2.1.0+26.2.jar
Minecraft 1.21.11	Fabric Loader 0.18.2+ and Fabric API 0.139.4+1.21.11 or newer hempdustry-fabric-2.1.0+1.21.11.jar	NeoForge 21.11.45+ hempdustry-neoforge-2.1.0+1.21.11.jar
Minecraft 1.21.1	Fabric Loader 0.16.5+ and Fabric API 0.105.0+1.21.1 or newer hempdustry-fabric-2.1.0+1.21.1.jar	NeoForge 21.1.209+ hempdustry-neoforge-2.1.0+1.21.1.jar

Both sides need Java 21, or Java 25 on 26.x. NeoForge needs nothing else; Fabric needs Fabric API.

1. Set up a Fabric or NeoForge server for your Minecraft version.
2. Put the Hempdustry jar in the server's mods/ folder, and on Fabric the Fabric API jar beside it.
3. Start the server once. It writes config/hempdustry.json with every setting at its default.
4. Give your players the same jar — same loader, same Minecraft version, same Hempdustry version — through a modpack or a download list.

Downloads: GitHub releases · CurseForge · NexusMods · Modrinth (coming). The player's side of this is on Installation.

A player without the mod cannot join

The mod adds blocks and items, and four data registries — the strains and the balance data — that the server sends to every player as they log in. A game without the mod has nowhere to put them, so the loader turns the player away at login. Keep everyone on the same Hempdustry version as the server, too.

Dedicated-server notes

• A clean boot is quiet. The mod logs a few info lines as it registers its content and no warnings. A warning or error naming hempdustry means something is off — most often a value in the config file, or a datapack — and the line says what.
• JEI on Minecraft 1.21.11 and 26.x: since Minecraft 1.21.2 a server no longer sends its recipes to players, so JEI shows Hempdustry's crafting recipes on a dedicated server only if JEI is installed on the server as well. The machine pages and the packing rows show either way, because the mod sends those itself. On 1.21.1 the server sends every recipe and none of this applies.
• The update checker never runs on a server. It is a client feature (client.updateCheck).
• The client section of the config file is written on the server too, and ignored there.
• An empty server stands still. On Minecraft 1.21.11 and 26.x a dedicated server that has had nobody on it for pause-when-empty-seconds (60 by default, in server.properties) pauses itself, and nothing grows or simmers while it is paused. And on every version, crops and machines only work in loaded chunks: an Infuser in a far-off outpost waits, and loses nothing, until someone comes back.

The config file

config/hempdustry.json, in the server's folder. The mod creates it on first start and writes it back out every time it reads it: complete, with a _comment line at the top of each section and the keys in alphabetical order, so a setting added in a later version shows up in your file at its default.

It has five sections: client (each player's own, on their own computer), effects, world, infuser and loot. Everything but client is decided by the server; a player's own file changes nothing on your server.

A broken file never stops the mod or the server from starting.

If the file…	the mod
is missing	uses the defaults and writes a fresh file
is empty	uses the defaults and writes them out in full — the quickest way to reset it
leaves out a key or a whole section	uses that key's default, and fills it in when it rewrites the file
holds a value outside its range	pulls it into range, logs Config <key> was <value>, clamped to <value>, and writes the corrected value back
is not valid JSON, or has a word where a number goes	logs an error naming the file, applies nothing from it and leaves the file exactly as it is, so you can fix the typo. The settings already running stay: the defaults at start-up, the last good read after a reload
has keys it does not know, or comments of your own	ignores them, and drops them the next time it rewrites the file

Applying changes

You changed	It takes effect
the effects, world or infuser section	at once, with /hempdustry reload (permission level 2) — on running Infuser batches and on creepers already in the world too
the loot section	/hempdustry reload, then /reload, which rebuilds the loot tables — or a restart. Chests already opened keep what they had
the client section	it is each player's own file; they restart their game
recipes, tags, loot tables or advancements in a datapack	/reload
strains, or the device, edible and green-out data	a restart of the server (in single player, close and reopen the world). Neither /reload nor /hempdustry reload re-reads them
worldgen — biome tags, placed features, NeoForge's biome modifiers	a restart, and only in chunks generated afterwards

Watch out: a strain or balance file with a mistake in it stops the world from loading, as any broken datapack entry does. A balance file that is simply missing falls back to the built-in numbers. Test datapack changes on a copy of the world.

Presets

Each block below is a complete config/hempdustry.json: anything it does not mention stays at its default, and the mod fills in the rest when it rewrites the file. Paste one over your file, or merge sections by hand to combine two, then run /hempdustry reload. Every key is explained on Configuration.

The website's config builder has these presets as buttons: press two and it writes the combined file for you, and every other key is there to fine-tune.

Hemp only, no drug effects

{
  "effects": {
    "enabled": false,
    "greenOut": false
  }
}

Smoking and edibles give no effects at all; the building blocks, cloth, hemp-seed food and everything else work as usual. Smoking gear can still be crafted and used — a hit still makes its sound and puff, takes its cooldown and wears the device — and an edible is just food. Turn greenOut off as well: enabled: false empties every effect, but a full green-out costs more than effects — it ends the player's helpful effects and empties their saturation — and it has its own switch.

No green-outs

{
  "effects": {
    "greenOut": false
  }
}

Everything else about smoking stays. For fewer rather than none, leave greenOut on and set "greenOutChanceMultiplier": 0.5 (half as likely).

Fast farming

{
  "world": {
    "cropGrowthMultiplier": 2.0,
    "machineSpeedMultiplier": 2.0
  },
  "infuser": {
    "minTimeTicks": 3000,
    "fullTimeTicks": 9000
  }
}

Hemp grows twice as fast in fields, Grow Pots and Hydro Trays; the Decarboxylator and the Hemp Press work twice as fast; and the Infuser can be emptied after 2:30 and finishes a full simmer at 7:30, half its defaults. A batch still holds up to 24 hemp — it simply takes them in faster.

No loot injection

{
  "loot": {
    "enabled": false
  }
}

The mod stops adding anything to vanilla's loot: no hemp seeds in tall grass, chests or village houses, no Beldía in the desert, no music discs in dungeons and mansions, no hemp in shipwrecks, the fisher's chest or fishing junk. Wild plants still grow in the world, and creepers still drop the two music discs — that comes from a vanilla tag, not from the loot injection. After /hempdustry reload, run /reload. The full list is on Modpack Guide.

No creepers in fields

{
  "world": {
    "creepersSeekHemp": false
  }
}

Creepers stop wandering into grown hemp fields and behave exactly like vanilla's. It applies at once, to creepers already in the world as well.

No nausea

{
  "effects": {
    "nausea": false
  }
}

An accessibility setting: nothing in the mod applies Nausea — not a harsh hit, not a green-out. Every other effect stays.

What survives a logout or a restart

• An edible still on its way is saved with the player. Eat a Space Cookie and log out, or have the server restart during the wait, and it still hits: the wait picks up where it left off when the player comes back, and the clock stops while they are away. A trip through the Nether or the End keeps it too. Dying loses it, as it always has.
• Machines keep everything — the Decarboxylator's trays and fuel, the Infuser's batch and its progress, the Hemp Press's input and output, and any anvil name.
• Plants and beds keep their state in the block itself: a plant's growth, its trims, the light it grew under and whether it stressed; a Grow Pot's water and feed; a Hydro Tray's water, fertiliser and pump.
• A packed device keeps its load and the hits left in its bowl, wherever it is stored.

In multiplayer

• Every sound comes from somewhere. All of the mod's sounds are mono, so a hit, a cough or a simmering Infuser is heard from where it happens and fades with distance, like any vanilla sound. Smoking sounds play under the Players volume slider, the machines under Blocks.
• Effects are personal. A hit or an edible affects the player who took it, never the players around them; each player has their own cooldown.
• The server decides the numbers. A player's own config file changes nothing on your server, and the machine screens show the timings the server is actually running.

Performance

What the mod costs a server, as far as the code shows:

• Three machines tick, the way a furnace does: the Decarboxylator, the Infuser and the Hemp Press. None of them sends anything per tick; their screens update only while a player has one open. The Infuser and the press push their output at a hopper's pace (every 8 ticks) and look for somewhere to push only once a second while there is nowhere.
• No block entity at all for the Grow Pot, the Hydro Tray, the Grow Lamp or the Sifting Box: what they hold is part of the block, and they cost nothing while nobody uses them. Placed bongs and Hemp Beds have block entities that never tick.
• Crops grow on random ticks, like wheat.
• Creepers drawn to hemp (the creepersSeekHemp setting): only half of all creepers take any interest, and each glances around about once every 12 seconds, reading a handful of blocks. It never loads a chunk, and nothing is saved or sent.
• The wisps over ripe plants are drawn by each player's game and cost the server nothing.

Updating and upgrading worlds

Back up first. Stop the server and copy the world folder, and config/ with it. Hempdustry's updates are built not to break worlds (see Stability Promise), but other mods, the loader and Minecraft itself make no such promise, and a backup costs a minute.

• 2.0.x to 2.1: drop the new jar in, on the server and for every player. The world opens as it was. A few things play differently, and are worth telling your players: creepers now and then wander into grown fields, plants in a field can stress and give schwag, three hemp wool over three planks now makes a Hemp Bed rather than a white bed, and the Hemp Harem Pants are undyed hemp now. The changelog has the full list.

  Note: the first time a player who had the old white-bed recipe in their recipe book joins, the log may show a line about the unrecognised recipe hempdustry:white_bed. The game drops it from their book; it is harmless.

• To a newer Minecraft (1.21.1 to 1.21.11, 1.21.11 to 26.2, 26.2 to 26.3): open the world with the newer version's build of the same Hempdustry version or a later one, on the same loader. Machine contents come through with their enchantments and other data, and machines keep their anvil names. One step at a time is the tested route (Installation). Minecraft does not support moving a world back down.
• Fabric to NeoForge, or back: not promised. Hempdustry keeps its own data the same on both, but the loader and your other mods may not.
• Betas are held to the same promise as full releases.

Reporting bugs

Open an issue on GitHub, or ask on Discord first if you are not sure it is a bug. These help most:

• the Minecraft version, the loader and its version, and the Hempdustry jar's name;
• everything else in your mods/ folder;
• logs/latest.log, and the crash report if there is one;
• your config/hempdustry.json and any datapacks, if you changed either.

Two known issues in 2.1.0: German and Russian may show some of 2.1's new text in English, and a hash spliff's name reads one level low (two buds and a pinch says II and gives III).

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See also: Configuration · Commands · Modpack Guide · FAQ