Describe it.
Watch it rise.
An AI building companion for Minecraft. Type a request in chat and it designs, self-reviews, and places an original build — houses, whole scenes, even sculpts like a fountain shaped like a banana.
Free to try — 15 credits a day, no account.
> /bm a cosy japanese cottage with a koi pond
✦ Conjuring your build… ⏳
I improvised a japanese-style cottage — 1,204 blocks. Hip roof, paper windows, a koi pond off the south path. Self-review: good.
✦ Placing 1,204 blocks… (326/tick)
Three words to a finished build
Type what you want
In-game chat: /bm a cosy japanese cottage with a koi pond. Plain English — no coordinates, no build tools.
It designs & self-reviews
Buildmancer improvises an original design in a learned style, renders it, critiques its own work, and fixes mistakes before you ever see them.
It builds in your world
The plan is placed block-by-block on the server thread, batched per tick — singleplayer, or on a Paper or Fabric server.
Real commands, real builds
Every card is an actual /bm build, rendered by Buildmancer's own isometric engine — the same view it self-reviews with.
house/bm a cosy japanese cottage
Learned style + palette, self-reviewed.
sculpt/bm a fountain in the shape of a banana
A banana silhouette, welling water in a stone basin.
sculpt/bm a lantern in the shape of a star
Glows — it picked sea-lanterns on its own.
house/bm a wizard tower in the shape of a giant mushroom
A building and a shape request at once — hollowed and given a door.
sculpt/bm a house in the shape of a pyramid
Hollowed, floored, and a door cut in.
sculpt/bm a giant parrot
It picked the scarlet-macaw palette itself — red, yellow and blue.
Not a schematic dump — an AI that thinks about the build
It designs, then judges itself
A build is rasterised, rendered, and critiqued by the AI before it's returned. Bad ideas get fixed automatically — you get the good version.
Sculpt mode
Shapes the box engine can't say. Ask for a cat, a dragon, a banana — it describes the subject as solids, looks at the result, and refines the silhouette.
Function & material from words
“a lantern shaped like a star” glows. “a golden throne shaped like a dragon” is gold. It reads your intent, not just the shape.
Whole scenes
“a cottage with a fountain, two oak trees and a cat statue” lays out a garden — paths, plinths, symmetry — not just one building.
Learns your styles
/bm learn a schematic and it improvises brand-new builds in that spirit — palette, proportions, roof grammar — never a copy-paste.
Refine in place
/bm edit “taller”, “add a tower”, “in stone” — it reworks your last build without you starting over.
Free to play. Buy credits when you want more.
1 credit = a house or scene · a sculpt = 5 credits
- ✓ Refills every day
- ✓ Every command unlocked
- ✓ Great for trying it out
- ✓ A weekend of building
- ✓ Never expires
- ✓ A key you paste into your config
- ✓ Best value per credit
- ✓ Never expires
- ✓ A key you paste into your config
- ✓ For servers and heavy builders
- ✓ Never expires
- ✓ Covers everyone on your server
You get a key on screen and by email — paste it into your config, no in-game code to type. Credits never expire, and buying is optional: the free daily allowance never runs out. Check a key's balance.
Two ways to run it
Pick the one that matches your world. Neither needs any configuration — both connect to the build service out of the box.
Paper / Spigot server
Minecraft 1.21.11 – 26.2 — including current Minecraft.
- 1Drop buildmancer-paper-0.2.2.jar into the server's plugins/ folder.
- 2Restart the server.
- 3Join and type /bm a cosy cottage. Players need nothing installed.
Singleplayer — Fabric
Minecraft 1.21.11, as a client mod or on a Fabric server.
- 1Install a Fabric profile for 1.21.11.
- 2Put buildmancer-0.2.2.jar and Fabric API in mods/.
- 3Turn on Allow Commands and type /bm a cosy cottage.
What it does, and what leaves your machine
Both jars are open about what they do. When you type /bm, the mod sends three things to the build service over HTTPS — your request text, your Minecraft player UUID (only to meter the free daily allowance), and a small heightmap of the ground around the build site (so the build sits on your terrain). Nothing else: no files, no inventory, no chat history, no account data. It installs nothing else, bundles nothing, and changes no system or browser settings. To remove it, delete the jar. The full detail is on the privacy page.
Both files are checksummed above and scanned clean on VirusTotal (0 / 64, 2026-07-23).
Will it run for me?
Buildmancer is a Minecraft: Java Edition mod. Here's exactly what that does and doesn't cover.
Paper / Spigot servers — including 26.2
The plugin runs on Paper 1.21.11 through 26.2, so it works on CURRENT Minecraft. Install it once server-side; players join from a vanilla client with nothing installed.
Java Edition 1.21.11 — Fabric
The mod, as a client mod for singleplayer, or installed once on a Fabric server.
Fabric on 26.2
Blocked upstream, not by us: Mojang publishes no official mappings for 26.2 and Fabric's yarn mappings aren't out either, so the mod can't be compiled against it. Use the Paper plugin for 26.2 in the meantime — it isn't affected.
Bedrock Edition · Forge
Bedrock (console, mobile, Windows edition) is a different engine and can't load Java mods at all — no workaround. Forge/NeoForge isn't supported yet.
Good questions
Does this work on any Minecraft version?+
Java Edition only — Bedrock (console, mobile, Windows edition) is a different engine and can't load Java mods at all. Which Java versions depends on the jar: the Paper/Spigot plugin covers 1.21.11 – 26.2, including the current release, while the Fabric mod is 1.21.11 only. That gap isn't our choice — Mojang hasn't published official mappings for 26.2 and Fabric's yarn mappings aren't out either, so no Fabric mod can be built against it yet. The plugin sidesteps this by compiling against Bukkit's stable API. On the latest Minecraft, use the plugin.
Do players on my server each need to install it?+
No — on either server jar you install it once, server-side, and players just run /bm with nothing installed. Paper and Spigot use the plugin; a Fabric server uses the mod. Only singleplayer needs the mod installed in your own client.
Do I need creative mode?+
No — creative isn't required. You just need “Allow Commands” turned on when you create the world (or operator / permission level 2 on a server), because Buildmancer places blocks with /fill. Survival works fine.
What's a “credit”?+
One build. Houses and scenes cost 1 credit; a detailed AI sculpt costs 5 (it does several vision-guided refinement passes). You get a free daily allowance, and can buy more.
How do I buy and activate credits?+
You buy a credit pack here and get a key (it looks like bm_live_…) on screen straight away and by email. Paste it into your config — token= in config/buildmancer.properties for the Fabric mod, or token: in the plugin's config.yml — and restart. That's it: no in-game code to type, and it works with the jar you already have. Credits never expire.
I play on someone else's server. Can I use my own key?+
No — and it's worth knowing before you buy. The key lives in the server's config, so it covers everyone on that server: it's a server licence, not a personal one. If you're a player on someone else's Paper server, the owner is the one who buys. Your own key works in singleplayer and on servers you run.
Can it build redstone contraptions?+
Not reliably — treat redstone as decoration, not machinery. Buildmancer designs structures: massing, walls, roofs, palettes, interiors. It has no model of redstone logic, so it can't design a circuit or adapt one to your space. If a build it learned happens to contain redstone it can place that copy with the block states intact, and it may well work — but nothing verifies it. The self-review checks doors, holes and clutter, never whether a circuit fires. Ask for “an automatic iron farm” and you'll likely get something that looks the part and doesn't function.
Is my world data sent anywhere?+
Only your text request plus a small patch of ground heights around the build site go to the build service, so it can sit the build on your terrain. No inventory, chat history, or account data.
Your next build is one sentence away.
Download the mod, type what you're imagining, and watch it go up block by block.