# Spawn runs its multiplayer game world on autonomous Fable-class agents

> Original title: Building a multiplayer game world with autonomous Fable-class models

- Source: Simon Willison
- Published: 2026-10-29T17:00:26.000Z
- Bad Influence: https://badinfluence.news/items/rpcko7i2i6pzbfnwe7nihcjz5
- Original: https://simonwillison.net/2026/Oct/29/how-i-built-the-most-ai-pilled-company-in-the-world/

## Summary

Simon Willison reports on Jacob Sansbury's account of Spawn, a multiplayer game where players modify the world through an in-game AI agent. Sansbury says the company spends over $3 million a month on tokens, with agents changing live code and shipping to production hourly. He says Fable 5 and 5.1 enabled this autonomy, while Opus 5.5 was insufficient and GPT-6 Astra disabled features when applying security fixes.