OpenAI launches its new family of models with GPT-5.6

It adds: “That advantage extends across the family: Terra performs just above Fable 5, while Luna outperforms Opus 4.8.”

The company says that 5.6 is now available across ChatGPT, Codex, and the OpenAI API. Availability per million tokens is priced as follows: Sol is $5 input / $30 output, Terra is $2.50 input / $15 output, and Luna is $1 input / $6 output.