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, including three models: Luna, Terra, and Sol, with pricing per million tokens and a 1 million token context window. It compares their performance against Claude models, highlighting agentic benchmarks and cost efficiency. The article also discusses new API features like Programmatic Tool Calling, multi-agent support, and prompt cache breakpoints, along with critical analysis of SWE-Bench Pro benchmarks.

0 comments

#Openai #LLM Benchmarks #Gpt 56