OpenAI just slashed API pricing for its GPT-5.6 Luna model by 80% — only three weeks after the series debuted. Luna input tokens drop from $1 to $0.20 per million, and output tokens drop from $6 to $1.20 per million.
Terra, the lineup's other new model, is getting a 20% price cut too, with input falling to $2 and output to $12 per million tokens.
OpenAI says the discounts come thanks to efficiency gains in the models, inference systems, and context management. Sol, the heavy hitter, isn't getting a price cut — but its API is gaining a Fast mode that runs up to 2.5x faster than standard.