OpenAI says the models were trained with similar methods to GPT-6 Astra, introduced earlier the same month, and that caching and inference gains funded the price cut.

The story was corrected

• 2026-10-03

  The first key point said GPT-6 Sol was down from $4 and $20. Those were GPT-5.6 Sol's promotional prices, not an earlier GPT-6 Sol price. It now says so.

  Why we corrected it: The key point dropped the condition our checked claim carries: the cut is measured against GPT-5.6 promotional pricing.

  What it said before: GPT-6 Sol costs $2 per million input tokens and $10 per million output tokens, down from $4 and $20.

The fact above is as the story now says it. All corrections

The exact words it rests on

Earlier this month, we introduced GPT-6 Astra ... We trained GPT-6 Sol and Luna with similar methods as GPT-6 Astra ... Improvements in caching and inference let us serve these models at lower cost, and we’re passing those savings directly on to users and customers

What the source said when we opened it, on 28 Sep 2026.

The source

Introducing GPT-6 Sol and Luna
OpenAI · 2026-09-22

Open the sourcearchived copy

Checked

Checked by the notis newsroom on 28 Sep 2026, against the source above.

In the story

OpenAI cuts GPT-6 Sol and Luna API prices against GPT-5.6 promotional rates 28 Sep 2026