GPT-6.1 Sol Upgrades Agentic Coding at a Lower Cached-Input Price
GPT-6.1 Sol upgrades GPT-6 Sol for agentic coding, computer use, and professional work. OpenAI positions it near GPT-6 Astra performance at one-fifth of Astra's standard token prices, with cached input at $0.10 per million tokens. It is available through the API and is rolling out in ChatGPT Work and Codex for eligible paid plans.
OpenAI announced GPT-6.1 Sol on September 29, 2026, as an upgrade to GPT-6 Sol for agentic coding, computer use, and professional work. OpenAI says the model approaches GPT-6 Astra's performance at one-fifth of Astra's standard input and output token prices, with a lower cached-input rate than the earlier Sol model. (OpenAI; OpenAI Developers on X; OpenAI Help Center)
Key Takeaways
- GPT-6.1 Sol is an upgrade to GPT-6 Sol for coding, computer use, and complex professional workflows. (OpenAI; OpenAI API model documentation)
- Standard API pricing is $2 per million input tokens, $0.10 per million cached input tokens, and $10 per million output tokens. (OpenAI; OpenAI API model documentation)
- The cached-input price is 50% lower than GPT-6 Sol's $0.20 rate, while the standard input and output rates are unchanged. (OpenAI; GPT-6 Sol API model documentation)
- The API model ID is
gpt-6.1-sol. OpenAI's model documentation lists a 1,050,000-token context window and 128,000-token maximum output. (OpenAI API model documentation) - ChatGPT Work and Codex access is rolling out, starting with Pro and expanding to Plus, Business, Enterprise, and Edu. GPT-6.1 Sol is not yet available in Chat. (OpenAI Help Center; OpenAI)
What Changed from GPT-6 Sol
OpenAI describes GPT-6.1 Sol as an upgrade to GPT-6 Sol, with stronger performance on agentic coding, computer use, and professional tasks. Its announcement reports improvements across coding, document understanding, and multi-step business workflows; those are OpenAI's own results, not independent benchmark measurements. (OpenAI; Tibo on X)
The standard input and output rates match GPT-6 Sol's, while the cached-input rate is halved. That makes the price difference most visible in workflows that reuse a prompt prefix or other context across requests. (GPT-6 Sol API model documentation; GPT-6.1 Sol API model documentation; OpenAI)
| Standard API price per million tokens | GPT-6 Sol | GPT-6.1 Sol | Official source |
|---|---|---|---|
| Input price per million tokens | $2.00 | $2.00 | GPT-6 Sol; GPT-6.1 Sol |
| Cached input price per million tokens | $0.20 | $0.10 | GPT-6 Sol; GPT-6.1 Sol |
| Output price per million tokens | $10.00 | $10.00 | GPT-6 Sol; GPT-6.1 Sol |
OpenAI says $0.10 cached input is 95% below GPT-6.1 Sol's standard input price and 50% below GPT-6 Sol's cached-input price. These are standard API rates; the model documentation also lists separate rates for cache writes, long prompts, and processing modes. (OpenAI; GPT-6.1 Sol API model documentation)
API Setup and Model Limits
For API requests, select GPT-6.1 Sol with the model ID gpt-6.1-sol. OpenAI's model documentation lists text and image input, a 1,050,000-token context window, and a maximum output of 128,000 tokens. Its supported reasoning-effort values are low, medium, high, xhigh, and max; medium is the default. (OpenAI API model documentation)
Use the Responses API for tool calling. OpenAI lists Chat Completions as supported without tool calling for GPT-6.1 Sol, so developers building agent loops should check their API integration before switching model IDs. (OpenAI API model documentation)
ChatGPT Work and Codex Availability
OpenAI's release notes describe a staged rollout in ChatGPT Work and Codex: Pro users are first, followed by Plus, Business, Enterprise, and Edu. The GPT-6.1 Sol announcement also says the model is not yet available in Chat. Enterprise and Edu workspace owners can manage access through workspace permissions, and availability may depend on plan and workspace settings. (OpenAI Help Center; OpenAI)
| Surface | Current documented status | Official source |
|---|---|---|
| OpenAI API | Available as gpt-6.1-sol. | OpenAI API model documentation |
| ChatGPT Work and Codex | Rolling out, starting with Pro and expanding to Plus, Business, Enterprise, and Edu. | OpenAI Help Center |
| Chat | Not yet available. | OpenAI |
The API is available now, while product access is staged. Check your ChatGPT plan and workspace settings, then test GPT-6.1 Sol on representative tasks before moving a production workflow. (OpenAI; OpenAI Help Center)
When to Evaluate GPT-6.1 Sol
Evaluate GPT-6.1 Sol when you need a cost-conscious model for agentic coding, computer use, or professional workflows that reuse context. Compare it with GPT-6 Sol on your own prompts and task success criteria, and include cached-input usage in the cost test. OpenAI positions GPT-6 Astra as the higher-cost comparison point; its performance claims should be treated as vendor-reported until reproduced on your workload. (OpenAI; GPT-6.1 Sol API model documentation)
Sources
- OpenAI, "Introducing GPT-6.1 Sol": https://openai.com/index/introducing-gpt-6-1-sol/
- OpenAI API, "GPT-6.1 Sol Model": https://developers.openai.com/api/docs/models/gpt-6.1-sol
- OpenAI API, "GPT-6 Sol Model": https://developers.openai.com/api/docs/models/gpt-6-sol
- OpenAI Help Center, "ChatGPT Release Notes": https://help.openai.com/en/articles/6825453-chatgpt
- OpenAI Developers on X, "GPT-6.1 Sol is here," September 29, 2026: https://x.com/OpenAIDevs/status/2104993035507712318
- Tibo on X, "Introducing 6.1 Sol," September 29, 2026: https://x.com/thsottiaux/status/2104986027953930613
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Frequently Asked Questions
What is GPT-6.1 Sol?
GPT-6.1 Sol is an upgrade to OpenAI's GPT-6 Sol model. OpenAI positions it for agentic coding, computer use, and professional work, with performance near GPT-6 Astra at a lower standard token price.
How much does GPT-6.1 Sol cost?
The standard OpenAI API prices are $2 per million input tokens, $0.10 per million cached input tokens, and $10 per million output tokens. OpenAI says the cached-input price is 95% below the standard input rate.
Where can I use GPT-6.1 Sol?
Developers can call it through the OpenAI API as `gpt-6.1-sol`. OpenAI is rolling it out in ChatGPT Work and Codex, starting with Pro and expanding to Plus, Business, Enterprise, and Edu. It is not yet available in Chat.
Which API should I use for GPT-6.1 Sol tool calls?
Use the Responses API for tool calling. OpenAI's model documentation says Chat Completions is supported without tool calling for GPT-6.1 Sol.