Simon Willison • 7/9/2026

The new GPT-5.6 family: Luna, Terra, Sol

This article covers the release of OpenAI's GPT-5.6 family, consisting of three models: Luna, Terra, and Sol, with varying pricing tiers per million tokens. It compares performance against Claude models, highlights benchmark results on agentic tasks and SWE-Bench Pro, and discusses new API features such as programmatic tool calling, multi-agent subagents, and prompt cache breakpoints. The article also includes early access impressions and notes on model guidance, making it relevant for developers and tech professionals interested in AI model advancements.

0 comments

#Openai #LLM Benchmarks #Gpt 56