GPT-6.1 Sol Explained: Who Gets It, What It Costs, How to Use It

OpenAI released GPT-6.1 Sol on September 29, 2026, one week after GPT-6 Sol. OpenAI's own summary is the useful one: it nearly matches GPT-6 Astra, the flagship, on agentic coding, computer use and professional work, at one fifth of Astra's input and output token prices.

Where you can use it

• ChatGPT: Plus, Pro, Business, Enterprise and Edu users get it in ChatGPT Work and in Codex. At launch it is not in the regular Chat view.
• Codex: the same plans. OpenAI says an Ultrafast version with up to 8x faster token generation is coming to Codex.
• API: model id `gpt-6.1-sol`.

API price

$2 per million input tokens, $0.10 per million cached input tokens and $10 per million output tokens. Cached input is 95% cheaper than fresh input, which matters for agents that resend the same context on every turn. For comparison, GPT-6 Astra is $10 in and $50 out.

What it is good at

OpenAI positions Sol as the everyday workhorse: multi-step coding in Codex, computer use, document-heavy professional work and business workflow automation. Astra stays the pick when a task is long, ambiguous or high-stakes and the extra cost is worth it.

Getting it through PerkShelf

• For coding tools that accept a custom endpoint (Codex CLI, Cursor, VS Code extensions), the Codex API token packs start at $2.99 for 10 million tokens over a day, with 50M over two days and 100M over three days. They run through a third-party gateway, not an OpenAI account; which OpenAI models the gateway serves is listed on your order.
• For an editor with OpenAI models built in, Cursor Pro+ for a year ($399.99) gives about three times Pro's agent usage across OpenAI, Claude and Gemini models.

How the gateway packs work is covered in Claude and Codex API credit explained.

Frequently asked questions

Is GPT-6.1 Sol free?

No. It is on paid ChatGPT plans and the paid API. Free and Go users can use GPT-6 Luna in the desktop app instead.

Should I use Sol or Astra?

Start with Sol. Move a task to Astra only when Sol falls short; Astra costs five times as much per token.