Anthropic Reports 1,000 Claude Agents Reproduce Fermat's Last Theorem Proof Using Only General Tools
Anthropic reports that 1,000 Claude Fable 5.2 agents reproduced the formal proof of Fermat's Last Theorem in 28.7 hours using only Git and PostgreSQL, without specialized math platforms or human steering.
Anthropic announced on November 9, 2026, that a team of 1,000 agents running an early version of Claude Fable 5.2 successfully reproduced the formal proof of Fermat's Last Theorem. Unlike the initial achievement in September, which relied on the specialized platform Prove2Me and direct researcher guidance, this experiment used only general-purpose tools like Git and a shared PostgreSQL database, with no human intervention during the process.
According to Anthropic, the experiment took 28.7 hours, consumed one-third of the output tokens used in the September baseline, and generated Lean code one-seventh the length of the original proof. The September formalization required a researcher and dozens of agents over 11 days, consuming approximately 6 billion output tokens.
The agents coordinated through a shared database: a 'lead' agent split the problem and assigned tasks to 999 'helper' agents. Helpers used database tables to track progress and claim subtasks, submitting code via Git for verification by a checker. This self-organization using general tools suggests that multi-agent systems handling complex, long-horizon problems may not strictly require domain-specific scaffolding platforms.
It is important to note that this remains a controlled 'toy experiment' reported by the vendor, without independent third-party reproduction. Anthropic acknowledges that while general tools were sufficient, specialized platforms like Prove2Me might still offer efficiency advantages in compilation speed and reuse of human results. The company also emphasized safety boundaries, noting all agents ran in network-isolated sandboxes under real-time monitoring.