OpenAI unveils GPT-5.6 Sol, Terra and Luna in limited preview, US government vets users

What happened

On June 26 OpenAI launched a limited preview of three GPT-5.6 models: the flagship Sol, mid-tier Terra and cheapest Luna. The preview is restricted to roughly 20 trusted partners whose names were individually approved by the US government.

Context and impact

This is the first OpenAI frontier model released under the federal pre-release review framework introduced by Trump's June executive order. OpenAI said in a blog post that restrictions like these should not become the norm because every additional week in review erodes the model's economic upside.

Details

• Sol sets a new SOTA on Terminal-Bench 2.1 and introduces a new 'max reasoning effort' tier plus an 'ultra mode' that orchestrates subagents
• Pricing per 1M tokens: Sol $5/$30, Terra $2.50/$15, Luna $1/$6
• Models are available via OpenAI API and Codex for a select group
• Broader availability expected in the coming weeks
• Approvals are happening 'customer by customer' per The Information