OpenAI ships GPT-5.6 with Sol and Luna on apps and API, plus a new RAG explainer for the rest of us

OpenAI just shipped GPT-5.6 — the headline version lands on apps and the API at the same time. Alongside it, two new models called Sol and Luna joined the lineup, giving you a spread from fast and cheap to heavy-duty reasoning. The whole thing is live today, no beta tag.

What matters for Brown working people is the RAG explainer that came with it. RAG — retrieval-augmented generation — is the trick of pulling in outside docs so the model doesn't just make things up. The explainer frames it like the auntie who always brings the extra book: it reaches into the shelf, grabs what you need, and brings it back. No jargon. You can read it in a minute.

Why this matters for us: OpenAI keeps moving the goalposts, and the models are getting faster and cheaper at the same time — tools we can use without needing a CS degree or a Silicon Valley salary.