OpenAI has slashed AI model prices again. Starting today: GPT-5.6 Luna: Price cut by 80% GPT-5.6 Terra: Price cut by 20% GPT-5.6 Sol: New high-speed mode added to the API, boosting speed by up to 2.5x After the adjustment, Luna's API pricing is now $1 per million tokens for input and $6 for output; Terra is $2.5 for input and $15 for output. And this price drop doesn’t just affect the API. The usage calculations for Luna and Terra in Codex and ChatGPT Work have also been adjusted downward, meaning the same subscription plan can now handle more coding, research, and Agent tasks.