OpenAI is limiting the release of its newest AI models to a “small group of trusted partners” at the behest of the U.S. government, the company said Friday.

The next generation GPT-5.6 lineup includes Sol, its flagship model; Terra, a more balanced model for everyday use; and Luna, a faster, lower-cost option. Although Sol is the company’s most powerful model, the Trump administration has restricted the release of all three. OpenAI said the preview is limited to partners “whose participation has been shared with the government.”

The administration’s request comes as the U.S. government puts new pressure on AI companies to restrict their most advanced systems. After Anthropic released its most powerful public model Fable 5, the administration ordered the company to remove access for any foreign national, prompting Anthropic to take the model down entirely. 

The incident has brought up questions of how much power the government should have over AI model releases. Dean Ball, a former White House AI adviser and soon-to-be OpenAI employee, says President Trump’s recent executive order — which asks certain AI companies to voluntarily submit their most advanced models for government review up to 30 days before release — has created a de facto involuntary licensing regime for frontier AI, leading to heavy-handed restrictions. 

The problem compounds, Ball argues, when the government doesn’t have clearly defined safety standards, which could lead to endless launch delays that might not only give a hand to China in the AI race, but also jeopardize the billions of dollars going to AI infrastructure buildouts. 

And while OpenAI did as the administration asked this time around, the AI firm made it clear it wasn’t happy with the arrangement.

“We don’t believe this kind of government access process should become the long-term default,” reads a Friday blog post. “It keeps the best tools from users, developers, enterprises, cyber defenders, and global partners who need them.”

OpenAI called the preview a “short-term step” that will put GPT-5.6 on the path to broader availability in the coming weeks, as the company works with the administration to develop a new executive order framework on cybersecurity, as well as a “repeatable process for future model releases.”

GPT-5.6 Sol specs

OpenAI says GPT-5.6 Sol is its strongest model yet, with improved agentic capabilities in coding, biology and cybersecurity. Sol introduces a “max” reasoning effort mode and an “ultra” mode that uses coordinated subagents to solve highly complex tasks (just the sort of neat trick that sends your token usage skyrocketing).

GPT-5.6 excels at several benchmarks, says OpenAI, including being slightly better at coding workflows than Anthropic’s Claude Mythos 5, which the Trump administration also effectively banned this month. OpenAI says GPT-5.6 Sol is also competitive with Mythos preview, but uses a third of the output tokens. 

To assuage any fears of its powerful models being unsafe, OpenAI says Sol includes its most robust security stack yet. It is, OpenAI says, heavily hardened against adversarial attacks and intentionally optimized to favor defensive cybersecurity work over offensive exploits. In other words, it’s designed to be hard to jailbreak, while prioritizing showing users how to defend against exploits, rather than how to hack into systems. 

OpenAI also says its safety guardrails are built directly into the core model’s behavior, rather than relying on a separate filter on top of it. The firm is likely trying to avoid the trap that caught Anthropic with Fable 5. In the brief moments when Fable 5 was available, whenever the model’s classifiers detected a high-risk topic— like cybersecurity, biology, or chemistry — it wouldn’t just block the prompt; it would route the request to an older model. The whole over-cautious flow and invisible downrouting led to many false positives and user backlash. 

While the GPT-5.6 models are initially available only to a select group of partners, OpenAI plans to make them more broadly available to people using ChatGPT, Codex, and the API soon. 

GPT-5.6 comes in three sizes with tiered pricing: Sol costs $5 per million input tokens and $30 per million output tokens; Terra costs half that; and Luna costs $1 and $6, respectively. OpenAI says it has also improved prompt caching to make repeated prompts cheaper and more predictable.