Building a multiplayer game world with autonomous Fable-class models
AI summary Jacob Sansbury says Spawn, a massively multiplayer game where players reshape the world by prompting an in-game agent named Savi, is now developed autonomously by a swarm of agents running on Fable models. The token bill exceeds $3 million monthly, which he puts at 30 times payroll. Agents push live changes hourly, treat an hour without a release as a SEV-0 incident, and can revert a faulty change in 30 seconds, with roughly 60% of work triggered by errors, bug reports or feature requests. According to Sansbury, Fable 5 and 5.1 enabled this autonomy, while Opus 5.5 fell short and GPT-6 Astra disabled every feature when asked to apply security fixes.