GPT-6.1 Sol
⧉GPT-6.1 Sol is the GPT-6 Sol upgrade OpenAI released on September 29, 2026. OpenAI says it comes close to GPT-6 Astra on agentic coding, computer use and professional work, at one fifth of Astra's list price. It has a 1,050,000-token context, up to 128,000 output tokens, reasoning_effort in five steps (low / medium / high / xhigh / max), image input and tool calling. Fully OpenAI-SDK compatible - set model to gpt-6.1-sol - and served on both /chat/completions and /responses. Pay-as-you-go, failed calls never billed; cached input bills at one tenth, and we do not add the long-context surcharge the official API applies.
Live Test · Playground
Try out GPT-6.1 Sol right here (available after login).
Input
Advanced
This model is served over a ChatGPT-subscription upstream that does not accept temperature / top_p / max_tokens (they are silently ignored). Use reasoning_effort below for thinking depth, and prompt wording for length.
Conversation
About GPT-6.1 Sol
GPT-6.1 Sol is the GPT-6 Sol upgrade OpenAI announced at DevDay on September 29, 2026, served on NezhaGate through the OpenAI-compatible API. OpenAI says it comes close to GPT-6 Astra on agentic coding, computer use and professional work, at one fifth of Astra's list price. It has a 1,050,000-token context, up to 128,000 output tokens per call, reasoning_effort in five steps (low / medium / high / xhigh / max), image input and tool calling, on both /chat/completions and /responses. Set model to gpt-6.1-sol and keep your SDK and request shape. Pay-as-you-go, failed calls are never billed, and cached input settles at one tenth of the input rate.
Use cases
Multi-file refactors, cross-module debugging, whole features written from a spec: coding work that needs sustained reasoning goes to 6.1 Sol for a fraction of what Astra costs.
Codex, Cursor and Claude Code speak the OpenAI-compatible endpoint, so switching to GPT-6.1 Sol is a one-field change to model, with tool calls returned in the OpenAI format.
Report writing, spreadsheet and data analysis, long-document review: professional work is one of the areas where OpenAI says it comes close to Astra.
1,050,000 tokens holds a whole repository plus its docs in one call, with no chunking and stitching of your own.
How to choose
Pick GPT-6.1 Sol when you want near-Astra coding and agent work at a controlled cost; keep GPT-6 Astra for the hardest reasoning, and use GPT-6 Luna for simple high-volume, low-latency work. They all belong to the GPT-6 family and share a 1,050,000-token context, so switching is a one-field change.
FAQ
How is it different from GPT-6 Sol?
How does it compare with GPT-6 Astra?
Which reasoning_effort levels are supported?
What are the context, output and knowledge limits?
Can I use /v1/responses?
Am I charged for failed calls?
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