# GPT-5.6 Sol beats Factorio — a rocket launch on peaceful mode

> An OpenAI model plays Factorio through code and finishes the game with a rocket launch.

- Org: Ryan Madden
- Date: 2026-10-31
- Category: showcase, article
- Source: https://ryanmadden.net/gpt-56-beats-factorio/
- Canonical page: https://ai-tldr.dev/releases/ryanmadden-gpt-5-6-sol-beats-factorio/

## In short

GPT-5.6 Sol, running in Codex at a low thinking level, launched a rocket in Factorio on peaceful mode in 13.5 hours of game time. Ryan Madden's harness gives it the same reach and fog-of-war limits a human player has.

## What it is

Ryan Madden reports that GPT-5.6 Sol beat Factorio on peaceful mode (no biters), launching a rocket after 13.5 hours of game time. The model ran inside Codex with a low thinking level.

## How it works

A game manager and a small Python library let the model play the game through code instead of the mouse. The library keeps the same limits a human GUI player has, such as player reach and fog of war. Madden notes the run needed a lot of manual work from the model, which carried supplies by hand between parts of the factory that were never connected.

## Why it matters

Factorio needs hours of planning, building and fixing, so it is a hard long-horizon test for agents. Madden says the run is a clear step up from his earlier GPT-5.5 attempts, which struggled to use transport belts at all.

## Who it's for

people building or evaluating long-running agents

## Links

- [Blog Post](https://ryanmadden.net/gpt-56-beats-factorio/)
- [Timelapse Video](https://www.youtube.com/watch?v=kLuSDUzKYZs)
- [HN Discussion](https://news.ycombinator.com/item?id=50318871)