1,000 agents, no researcher: a self-organized Lean proof of Fermat
A thousand agents running an early build of Claude Fable 5.2 formalized Fermat's Last Theorem in Lean in 28.7 hours, without the Prove2Me coordination platform or a researcher steering the work. Each agent got its own network-isolated sandbox, a Git branch, a shell, Lean plus Mathlib, and access to a shared Postgres database. The lead model spent its first ten minutes creating five tables to announce orders, assign statements, collect notes, queue subtasks and log finished work; helpers then claimed tasks and reported progress through them. After most agents judged 47 of 60 statements infeasible, the lead reallocated nearly everyone to the remaining ten, and later built a 2,418-node task tree up to ten levels deep for Langlands–Tunnell. The post details the safety stack—sandboxing, a blocking classifier on every tool call, and offline monitoring—and concedes that agents still misjudge difficulty and quit early.