CurseForge · Minecraft mod
ECB Builder
ECB Builder is a powerful command-based Minecraft building mod that turns simple /ecb prompts into original structures. It helps players quickly create houses, towns, cities, castles, underground bases etc
Quick answer
Which ECB Builder release should I use?
ECB Builder targets 1.21.1 with Fabric. The project page does not say whether this file belongs on the client, dedicated server, or both. No extra mods listed for this file.
Where it goes
Is ECB Builder required on the client, server, or both?
The project page does not say whether this file belongs on the client, dedicated server, or both.
The source does not explicitly classify this release as client-only or server-only.
What else does ECB Builder need?
ECB Builder. Change the file and its required mods may change too.
This file does not list any required mods. Do not add a library just because a different file uses it.
This file does not list any required or optional mods.
Before you install it
Add ECB Builder without breaking your instance.
Built for ECB Builder. Pick another file and the loader, install side or required mods may change.
- 01
Stick to this file
Use ECB Builder. It targets 1.21.1 with Fabric; another release may have different loader, side or dependency requirements.
- 02
Bring the mods it needs
This file does not list any required mods. Do not add a library just because a different file uses it.
- 03
Put it on the correct side
The project page does not say whether this file belongs on the client, dedicated server, or both.
- 04
Pick the file you checked
Use the “Get this file” button beside ECB Builder. It opens that exact file at the source.
About this project
What does ECB Builder add?
ECB Builder
ECB Builder is a Minecraft Java Fabric 1.21.1 mod that lets players generate original structures using simple /ecb commands. Instead of building every block by hand, players can type prompts like /ecb build a house, /ecb build a city, /ecb build a castle, or /ecb build an underground base, and ECB Builder will create the structure directly in the world.
ECB Builder is designed to be more than a basic house generator. It can create houses, towns, cities, castles, towers, bridges, farms, greenhouses, parks, statues, ships, docks, underground bases, underground cities, cave builds, survival rooms, storage areas, and more.
Features
Simple
/ecbcommand systemPrompt-based structure generation
Houses, cities, towns, castles, underground bases, and underground cities
Preview and confirm system
Undo support
Saved build support
Terrain blending for hills, slopes, and uneven ground
Biome-adaptive block palettes
Better foundations so towns and cities do not float awkwardly
Underground builds with ladder access, tunnels, doors, and lighting
Safer furniture placement so doors and beds are not blocked
Dense lighting for underground structures
Mob clearing support for underground builds
Sorted storage support
Safe furniture and interior generation
Balanced survival-friendly loot
Optional EPC Buildet API support for smarter planning
Example Commands
/ecb help/ecb examples/ecb build a house/ecb build a large medieval city/ecb build a hidden underground base/ecb build an underground city/ecb preview a castle/ecb confirm/ecb undo/ecb add light/ecb add loot/ecb add animals
Optional API Support
ECB Builder can work by itself, but it also supports the optional EPC Buildet API companion mod. The API acts like a local planning brain for ECB Builder and helps with underground structures, city planning, Build IDs, safer placement rules, access tunnels, lighting plans, and structure layout logic.
The API is optional, but recommended for the best underground base and underground city generation.
Survival-Friendly Design
ECB Builder is made to help players build faster without breaking survival gameplay. It avoids overpowered rewards, rare loot, diamonds, netherite, enchanted gear, and progression-breaking items.
The mod also focuses on original Minecraft-style builds instead of copying copyrighted or trademarked designs.
Requirements
Minecraft Java Edition 1.21.1
Fabric Loader
Fabric API
Java 21
Project description from CurseForge.
Pick your setup
ECB Builder by Minecraft version and loader
Choose the version and loader you play, then open the matching release.
Check the dependencies, then try the file in a copied instance before changing a world you care about.
Recent files
ECB Builder versions and loaders
ECB Builder
ecb-builder-3.0.10.jar
13 Jun 2026
Looking for an older file? The official CurseForge project page is in Resources.