npc2

npc2 is an experimental Fabric mod for Minecraft that drops autonomous survival NPCs into your world. Each one runs on a weighted survival plan, keeps persistent memories, uses vanilla mob physics, and makes its decisions through a node-based behavior graph covering gathering, crafting, combat, storage, movement, and sleep.

npc2 can be used in singleplayer worlds, LAN, and multiplayer servers.

npc2 is under active development. Go in expecting NPCs to reshape the terrain around them as they mine and build.

Requirements

npc2 requires Fabric API and Fabric Language Kotlin.

• [Latest] Version 0.3.1-alpha+26.3 supports Fabric API 0.161.0+26.3 and compatible newer Fabric API releases for Minecraft 26.3.
• [Legacy/26.2] Version 0.3.0-alpha+26.2 supports Fabric API 0.154.2+26.2 and compatible newer Fabric API releases for Minecraft 26.2.

For Servers: Install npc2 and its dependencies on both the server and every connecting client.

Singleplayer: Install npc2 and its dependencies on your Minecraft client.

LAN: Install npc2 and its dependencies on every player's client.

Quick start

Version 0.3.0-alpha and newer

Open the vanilla Creative inventory's Spawn Eggs tab and use the Survivor NPC Spawn Egg on solid, open ground.

Players with permission to use commands can also click or enter:

/give @s npc2:fake_npc_spawn_egg

When you enter a world, npc2 displays a formatted quick-start message in chat containing the spawn command, debug controls, and issue-tracker link.

Version 0.2.1-alpha and earlier

Open npc2's Creative inventory tab and use the Survivor NPC Spawn Egg on solid ground. You may need to use the inventory arrows to find the tab.

Alternatively, enter:

/give @s npc2:fake_npc_spawn_egg

Debug panel — 0.3.0-alpha and newer

Aim near a living NPC to display a compact debug panel containing its name, entity ID, health, and debug controls.

• Press X to pin the selected NPC and expand the panel.
• Press X again to unpin it.
• Press F8 to toggle all npc2 debugging, including the panel, glowing outline, and path visualization.
• Both controls can be rebound under the Debug category in Minecraft's Controls menu.

The expanded panel displays the NPC's current decisions, movement and path state, resource requirements, equipment, inventory, and other AI information.

For the cleanest layout, use a GUI scale of 3 or lower.

Player interaction — 0.3.0-alpha and newer

NPCs are friendly toward players by default. An NPC only retaliates against a Survival or Adventure player who harms that specific NPC. Creative and Spectator players are never targeted.

The retaliation duration can be changed in:

.minecraft/config/npc2/npc2.properties

Known issues in 0.3.0-alpha

• The debug overlay may appear uneven at GUI scales above 3.
• NPCs move very slowly while floating in water.
• NPCs may occasionally freeze while retaliating against a player. They resume once the player leaves their detection range, enters Creative mode, or the configured player_retaliation_ticks duration expires.

These issues are planned to be fixed in future releases.

More documentation

Visit the npc2 GitHub README for installation instructions, configuration options, gameplay details, troubleshooting, and development documentation.

Report bugs through the npc2 issue tracker.