Copy cuboid regions to files. Paste them back exactly where you mean to — anchored to your position.

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Copy Paster is a Fabric client + server mod for survival and creative builders who want a fast, visual way to duplicate structures without leaving the game. Select a box with keybinds, name it in chat, then paste it later — position follows where you stand at copy time and paste time, so offsets stay intuitive.

• [ / ] copy — two corners, live wireframe preview, name in chat
• Paste options — absolute coords, rotation, mirror, skip air, overwrite confirm
• Paste ghost preview — cyan box when blocks would be overwritten (respects rotation/mirror)
• Undo — /pasteundo restores the last paste (in-memory until restart)
• Ukrainian (uk_ua) — full UI strings alongside English
• Configurable limits — server copypaster-server.yml; client highlight + preview cap via copypaster.yml or Mod Menu
• Web UI (optional) — browser 3D viewer/editor with texture-accurate block preview, palette remap, voxel paint

Maintainer docs: CLAUDE.md · Release notes: CHANGELOG.md

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Install

Where	What
Dedicated server	copy_paster-<version>.jar in mods/ + Fabric API
Each player who copies	Same JAR in client mods/ + bind [ / ] under Options → Controls → Miscellaneous

Server-only mode: /paste, /copylist, /copyinfo, /copydelete, /copyweb, and the web UI still work. World copy requires the client mod and keybinds.

Optional: Mod Menu + Cloth Config for in-game client settings.

Optional: LuckPerms — grant copypaster.* nodes to non-ops; vanilla operators are always allowed (copy + commands).

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Quick start

1 · Save a region

1. Stand at the anchor point you want for this copy.
2. Bind and press [ on corner 1, then ] on corner 2 (wireframe follows your crosshair for the end corner).
3. Type a structure name in chat (a–z, 0–9, _, -, max 64 chars). Type cancel to abort (timeout from server config, default 60 s).

2 · Paste it back

1. Stand in the same relative spot you used when copying (or use at — see below).
2. /paste <name> — if the ghost warns about overwrites, run the suggested … confirm command.
3. Save the undo ID from chat for /pasteundo <id>.

Examples:

/paste house
/paste house at 100 64 -20
/paste house rotate 90 mirror left_right noair confirm

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Commands

Command	Description
/paste <name>	Paste at player-relative anchor
/paste <name> at <x> <y> <z>	Paste with min corner at world coordinates
/paste <name> rotate <90|180|270>	Rotate before placing
/paste <name> mirror <left_right|front_back>	Mirror before placing
/paste <name> noair	Skip air blocks in the structure (do not clear destination air)
/paste <name> … confirm	Paste after overwrite warning (modifiers can be combined)
/pasteundo <id>	Restore blocks from one paste
/copylist	List saved structures
/copyinfo <name>	Size, dimension, offset, metadata
/copydelete <name>	Remove .nbt + .json
/copyweb	Print web UI URL (when enabled)

Access: vanilla operator always has full access. With LuckPerms installed, non-ops need the nodes below:

Node	Allows
copypaster.copy	[ / ] region copy (C2S)
copypaster.paste	/paste
copypaster.pasteundo	/pasteundo
copypaster.copylist	/copylist
copypaster.copyinfo	/copyinfo
copypaster.copydelete	/copydelete
copypaster.copyweb	/copyweb

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Web UI (viewer + editor)

Optional browser interface for saved structures. Disabled by default.

Feature	Description
3D viewer	Orbit + WASD pan, layer slider, isometric toggle
Colors / Textures	Map-color cubes or Minecraft 1.21.4 textures (cutout, glass, entity blocks)
Palette remap	Replace one block type with another across the structure
Voxel paint	Click blocks to repaint or erase
Download	Export edited .nbt

1. On the server, edit config/copypaster-server.yml:
   • limits.maxVolume / limits.sessionTimeoutSeconds (optional)
   • web.enabled: true
   • web.port: 8792 (default)
   • web.bind: 127.0.0.1 (or 0.0.0.0 for LAN/VPN)
   • web.publicHost: 192.168.50.100 (optional URL hint in logs)
   • Copy web.authToken for the browser login screen
2. Restart the server. Run /copyweb in-game for the URL.
3. Open the URL, paste the token, select a structure, edit, Save — then /paste in-game as usual.

Build embedded assets: ./gradlew buildWeb (included in ./gradlew jar). After a server update, hard-refresh the browser (Ctrl+Shift+R).

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Controls

Input	Action
[	Set corner 1 (look at a solid block)
]	Set corner 2 and send region to server
Chat name	Save structure after corners are set
cancel in chat	Abort naming session

Keybinds are unbound by default — assign under Options → Controls → Miscellaneous → Copy Paster.

Web viewer (when enabled)

Input	Action
Drag	Orbit camera
Scroll	Zoom
W / A / S / D	Pan (click viewer first)
Q / E	Down / up

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Limits & storage

Max volume	limits.maxVolume in server config (default 32 768); client preview cap in config/copypaster.yml
Copy session timeout	limits.sessionTimeoutSeconds in server config (default 60)
Files	Server copypaster/structures/ — <name>.nbt + <name>.json
Undo	In memory only; cleared on server restart
Highlight colour	Client config/copypaster.yml

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Build

./gradlew clean jar
# → build/libs/copy_paster-<version>.jar

Requires Java 25. See CLAUDE.md for deploy runbook (Fabric on gserver).

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Roadmap

Planned work — not implemented yet.

In-game functionality

• Paste with physics — no air below pasted blocks (support blocks stay filled)
• Persistent undo — survive server restarts
• Copy locator metadata — store capture origin and last paste in .json; expose in /copyinfo and the web UI

Web viewer

• Sign text, item frames, and paintings in 3D
• More modded blocks — texture and display handling beyond vanilla + current fallbacks
• Banner pattern composing — full pattern NBT on banner geometry (not base dye only)
• Performance mode for huge structures — LOD or cull distant voxels

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License

See repository license file if present; otherwise treat as private CrazyHouse tooling until a license is added.