Run a 50-agent civilization in survival Minecraft and watch it self-organise

Y Combinator's labs team, working with Olam Labs, wanted to study how swarms of agents coordinate. No harness for long-running Minecraft agents existed, so they built one and open-sourced it: the core loop runs on Pi, and the agents act through tools built on Mineflayer's scripting layer. Each agent could observe the world, keep memory, write and run scripts and send direct messages. In the run they call Civ50, 50 agents on GPT-6.1 Sol got one goal, build a thriving civilization, plus an agent directory and a shared sandbox machine for notes, and were left alone in a survival world for three hours.

The agents cleared almost every tree near spawn in about 90 seconds. The first agent in the directory, Ada, became the leader by default and wrote the colony plan into shared files. The first night killed 22 agents (34 deaths over the run), after which the group turned cautious, dropped building and scouting, and spent most of the run in shelters. One agent kept a food queue file and approved rations by message, catching misdelivered food and stale reports. In all they sent about 5,900 messages. The write-up also covers a second set of runs in Mindustry.

Dying cost the agents nothing but their gear, yet they still became very risk-averse. An HN commenter found their play slow and almost turn-based, even in a Bed Wars mode that should have rewarded speed. Fifty agents sharing scarce food turned the goal into survival logistics rather than building.