OpenAI releases GPT-6.1 Sol at a fifth of GPT-6 Astra's price, and halves the cost of cached input

OpenAI released GPT-6.1 Sol on 29 September, at its DevDay. Its API changelog describes it as released “for complex coding and professional work at a lower cost than GPT-6 Astra.”

The price is the news. For prompts up to 272,000 tokens, OpenAI's pricing page lists $2 per million input tokens, $0.10 per million cached input tokens, $2.50 for cache writes and $10 per million output tokens. That matches GPT-6 Sol except for cached input, which halves from $0.20. GPT-6 Astra, released a week earlier and covered here on 22 September, lists at $10 input and $50 output, so the new model's standard rates are a fifth of Astra's.

OpenAI's ChatGPT and Codex changelog says: “GPT-6.1 Sol offers near-Astra performance for complex work at a lower cost than Astra.” That is OpenAI's claim. The benchmark figures behind it were on an OpenAI page that refused access during this run, so no score is given here. TechCrunch reports the model is available to paid plans in ChatGPT Work and Codex.

For anyone running agents that resend the same long context many times, a halved cached-input rate is a direct cost cut, and it lands in the same week Anthropic held Sonnet 5.5 at the same $2 and $10 list price. The open question is whether “near-Astra” survives outside measurement.

• Confirmed GPT-6.1 Sol released 29 September at $2 input, $0.10 cached input, $2.50 cache write and $10 output per million tokens, for prompts up to 272K tokens. OpenAI API changelog
• Confirmed GPT-6 Sol's cached input is $0.20; GPT-6 Astra lists at $10 input and $50 output per million tokens. OpenAI API pricing
• Claimed “GPT-6.1 Sol offers near-Astra performance for complex work at a lower cost than Astra.” OpenAI ChatGPT & Codex changelog
• Reported Available to paid plans in ChatGPT Work and Codex. TechCrunch