GPT-6 Astra successfully closed portal in 23 hours!

cozyblaze integrated GPT-6 Astra into Portal using a bespoke interface, and asked GPT-6 to play Portal by itself, from beginning to end, without any human intervention. It did just that, completing it in 23 hours and 43 minutes.

1How It Worked

It used MCP and a fork of SourcePauseTool to pause the game while it was “thinking”. Each pause, it got a screenshot of the screen, a location of the character, and camera position. It then selected an action and resumed playing. Full source code and documentation are available on GitHub.

2Cost and Context

At the current list price, running GPT-6 Astra cost approximately $570 in tokens. cozyblaze paid $200 for a Codex subscription. In 2016, OpenAI said they want to build an agent capable of playing many different video games, and GPT-6 Astra (“the worst model we’ll ever get”) is a first, public step towards this.

Portal is a physics puzzle game where players must think spatially and plan ahead. Playing this usually takes 3–5 hours. This agent finished it in an order of magnitude more time, but without a single intervention. Last year, this would’ve required non-stop operator involvement.