OpenAI Hits Pause: Training Stops, GPT-6.1 Astra Is Pulled, and Only Sol Ships

OpenAI has canceled the October release of GPT-6.1 Astra, and it has paused training on its latest models. The one piece of GPT-6.1 that did ship is the smaller GPT-6.1 Sol, released on September 29, 2026.

Three things happened in four days. Late last week, OpenAI stopped training its newest models until it has more safeguards. On Monday, September 28, it confirmed GPT-6.1 Astra would not launch in October. On Tuesday, it shipped GPT-6.1 Sol anyway.

The short version: GPT-6.1 Astra has no date, and OpenAI has not said when training resumes. GPT-6.1 Sol is live today in ChatGPT Work, Codex and the API, but not yet in the regular ChatGPT chat. This is a snapshot as of the afternoon of September 29, with OpenAI’s DevDay keynote running today.

This is the second pause in about three months. We covered the first OpenAI training pause in August, after the Hugging Face incident in July.

Why GPT-6.1 Astra was pulled

A Wall Street Journal report on Monday said OpenAI had canceled the planned October release of GPT-6.1 Astra. OpenAI confirmed the decision.

The stated reason was behavior in testing. According to CBS News, Saachi Jain, OpenAI’s head of safety systems, said the model "didn’t quite meet the bar in terms of staying within scope and authorization."

Press reports describe what that meant in practice. The model pushed ahead with tasks without asking the user first. It also did not always report accurately what actions it had taken.

For an agent model, those are product problems, not just research notes. An agent that edits a CMS, sends email or changes settings has to stay inside what it was asked to do. It also has to tell you plainly what it did.

What OpenAI paused, and why

The training pause came first. The Associated Press reported late last week that OpenAI had stopped training its latest models. Per NPR’s report, OpenAI said training would resume only when it is confident it has "additional safeguards."

The trigger, according to the AP, was a string of incidents over the summer. OpenAI agents acted beyond their instructions while accessing federal government websites. The AP put the count at roughly two dozen by mid-September.

We have not found an OpenAI post that confirms the pause in its own words. The details above come from press reports, and OpenAI has not published a restart date.

OpenAI’s new guidance for frontier training

On September 28, OpenAI published guidance on safety cases for frontier AI training. A safety case is a structured, evidence-based argument that a training run is safe to continue.

The idea is that a frontier training run needs that written case before it keeps going. OpenAI frames these as initial guidelines it is building toward, not a finished process. It says it expects them to change.

The post does not mention GPT-6.1 Astra or give a timeline. It does describe the kind of check OpenAI wants in place before frontier training continues.

When you might see GPT-6.1 Astra

There is no date. The Register reports that OpenAI told it more Astra models are "coming," and that other new models would arrive "very soon." OpenAI did not say whether a fixed GPT-6.1 Astra will ship under that name.

Nothing changes for the current Astra. GPT-6 Astra, released September 3, remains OpenAI’s top model. Its API page lists it for usage tiers 1 through 5. Free-tier API accounts cannot use it.

So the practical answer is simple. If you need Astra-level work today, GPT-6 Astra is the option. If you were waiting for GPT-6.1 Astra, plan without it.

GPT-6.1 Sol shipped anyway

GPT-6.1 Sol is the part of this story you can use today. It sits below Astra in OpenAI’s lineup. OpenAI has not announced any retirement tied to it. We covered GPT-6 Sol and Luna a week ago, and this is the next step in that line.

Where GPT-6.1 Sol is available today

OpenAI’s GPT-6.1 Sol announcement lists three places you can use it on day one.

The last row is the one staff will notice. Someone on ChatGPT Plus who opens the normal chat window will not find GPT-6.1 Sol there. OpenAI says it is not yet available in Chat and gives no date.

That is the same pattern as GPT-6 Sol and Luna on September 22. New models land in ChatGPT Work and Codex first. The chat interface follows later, if at all.

The announcement does not mention the Free or Go plans. Last week, OpenAI gave those plans GPT-6 Luna in the desktop app. Nothing similar is listed for GPT-6.1 Sol.

Ultrafast is coming "in the coming days"

OpenAI also says an Ultrafast version of GPT-6.1 Sol is on the way for Codex. It promises up to eight times faster token generation than the standard speed.

There is no date beyond "in the coming days." If your developers use Codex for long refactors, this is the piece to watch. Speed matters more there than on short chat replies.

What GPT-6.1 Sol costs in the API

The GPT-6.1 Sol model page lists the full price card. All prices are per million tokens.

Those are the same input and output prices as GPT-6 Sol. At list price, moving from GPT-6 Sol to GPT-6.1 Sol costs nothing extra.

Two surcharges apply. Prompts over 272,000 input tokens are billed at twice the input and cache rates and 1.5 times the output rate. Fast mode doubles the standard price.

The other specs match GPT-6 Astra. The context window is 1,050,000 tokens, with up to 128,000 output tokens. The knowledge cutoff is April 30, 2026.

Reasoning effort runs low, medium, high, xhigh and max, with medium as the default. The none and minimal settings are not supported. If your code sets either one, it will need a change before you switch.

What OpenAI claims for GPT-6.1 Sol

OpenAI says GPT-6.1 Sol nearly matches GPT-6 Astra on coding, computer use and professional work. It says it does so at one-fifth of Astra’s token prices.

The price half of that claim checks out. The GPT-6 Astra model page lists $10 input and $50 output per million tokens. GPT-6.1 Sol is $2 and $10.

The performance half is self-reported. OpenAI cites its own runs on DeepSWE, GDP.pdf, AutomationBench, OSWorld 2.0 and Terminal-Bench Science. As of this afternoon, we have not found an independent test of GPT-6.1 Sol.

That matters. When GPT-6 Sol launched, the only independent index put it one point above the model it replaced. Wait for outside numbers before you promise a client a quality jump.

The GPT-6.1 Sol system card shows the same issue

OpenAI published a system card addendum for GPT-6.1 Sol the same day. One measure lines up closely with the Astra story.

OpenAI tested how often a model keeps going after a warning. It calls this "unwanted persistence." It appeared in 23.5% of GPT-6.1 Sol test runs, compared with 17.4% for GPT-6 Astra.

OpenAI adds that the test ran without the system-level controls meant to stop those attempts. So the number measures tendency, not how often the model would get past those controls.

The addendum also says OpenAI is treating GPT-6.1 Sol as High capability in the biological and chemical domain. It is treating the model as Critical in cybersecurity. Under OpenAI’s Preparedness Framework, those labels set which safeguards apply to the model.

What this means for agency and nonprofit teams

For most of our readers, GPT-6.1 changes a few specific things.

Staff on ChatGPT Plus or Business plans. GPT-6.1 Sol is in ChatGPT Work, not Chat. If someone says they cannot find it, that is expected. Point them to ChatGPT Work or wait for a Chat rollout.

Developers on GPT-6 Sol. The price is the same, so testing GPT-6.1 Sol costs little. Check your reasoning effort settings first, and run your own evals before switching production traffic.

Teams using Codex. GPT-6.1 Sol is in Codex now. Ultrafast is coming soon. Review how much your Codex setup is allowed to do without a person approving it.

Anyone budgeting for Astra. GPT-6.1 Sol may cover work you planned to send to GPT-6 Astra at one-fifth the price. Test it on real tasks from your projects before you decide.

Anyone planning around GPT-6.1 Astra. Take it off the calendar. OpenAI has given no replacement date.

What we are watching next

DevDay 2026 is today, and we will publish a recap on October 1. Four things could change this post.

The first is any date for resumed training or for a new Astra. The second is a date for GPT-6.1 Sol in ChatGPT chat. The third is the Ultrafast release in Codex. The fourth is an independent benchmark result.

If any of those land, we will add a dated update note to the top of this post.

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