We’ve created GPT-4, the latest milestone in OpenAI’s effort in scaling up deep learning. GPT-4 is a large multimodal model (accepting image and text inputs, emitting text outputs) that, while worse than humans in many real-world scenarios, exhibits human-level performance on various professional and academic benchmarks.
Full paper available here: https://cdn.openai.com/papers/gpt-4.pdf
Sub-Section 2.9 should have been an entire section. ARC used GPT-4 to simulate an agent in the wild. They gave GPT-4 a REPL, the ability to use chain of thought and delegate to copies of itself, a small amount of money and an account with access to a LLM api. It couldn't self replicate.