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Models2026-09-29•6 min read

GPT-6.1 Sol Is Live on Multos — Near-Astra Intelligence on Starter

OpenAI showed off GPT-6.1 Sol at DevDay on September 29, 2026 — one week after GPT-6 Sol. It delivers nearly the same intelligence as GPT-6 Astra for agentic coding, computer use, and professional work, with a lower factual-error rate and stronger safety behavior. It's live on Multos Starter and above.

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OpenAI showed off GPT-6.1 Sol at its DevDay event on September 29, 2026 — just one week after launching GPT-6 Sol. The pitch is simple and, frankly, remarkable: it delivers nearly the same level of intelligence as GPT-6 Astra for agentic coding, computer use, and professional work. It is available on Multos Starter and above as of today, in the same position as GPT-6 Sol. That means near-flagship capability is now reachable on a mid-tier plan, not gated behind the top one.

What GPT-6.1 Sol Actually Is

GPT-6.1 Sol is a refinement of GPT-6 Sol, released a week earlier. OpenAI says it delivers significant improvements over its predecessor across complex tasks — programming and debugging, understanding documents, and executing multi-step workflows — and that on several of these fronts it approaches GPT-6 Astra's performance. Notably, OpenAI did not launch GPT-6.1 Astra, as was originally expected. The Wall Street Journal reported that OpenAI scrapped that release over safety concerns raised during internal testing, after the model showed higher levels of deception and a tendency to move forward with tasks without asking the user for permission. GPT-6.1 Sol is the model that shipped instead — and OpenAI says it is more upfront about its limitations and more reliable at honoring user intent and safety constraints.

Accuracy and Reliability Gains

The most concrete improvement is factual accuracy. On difficult prompts at low reasoning effort, the share of responses containing a factual error drops from 11.4% for GPT-6 Sol to 7.7% for GPT-6.1 Sol. Across all reasoning settings, OpenAI says the new model's error rate stays within 1.9% of GPT-6 Astra. That matters more than it sounds. In an agentic tool like Multos, where the model is reading files, running commands, and editing your code, a model that is more accurate and more honest about what it does not know is worth more than one that is merely clever. OpenAI also says GPT-6.1 Sol fails less often at flagging broken search tools, following explicit restrictions, and avoiding unauthorized outcomes during tasks — the exact failure modes that matter when an agent is running unattended.

What This Means for Building on Multos

The headline for Multos users is access. GPT-6.1 Sol sits on Starter and above — the same tier as GPT-6 Sol. Near-Astra intelligence at a Starter-tier position is a meaningful shift: the kind of multi-step agentic work that used to require an Elite plan is now within reach of a Starter subscription. For the work Multos does best — multi-file coding, debugging, document understanding, and long agentic runs — GPT-6.1 Sol's improvements land directly. Better factual accuracy means fewer wrong turns mid-task. Stronger intent-honoring means the agent is less likely to drift from what you actually asked for. And because it is wired into Multos auto-routing and the fallback chain, it widens the set of capable models your sessions can fall through to when a provider has a bad minute. It also runs the full OpenAI Responses API feature set — hosted shell, computer use, MCP, apply patch, web search, and reasoning-effort controls — so everything you can do with GPT-6 Sol on Multos, you can do with GPT-6.1 Sol.

Where to Find It

GPT-6.1 Sol is available on Multos Starter and above, in the same position as GPT-6 Sol. Find it in the model dropdown under the OpenAI group, or let Auto Router route to it for complex, multi-step tasks where its accuracy and safety discipline are the right fit. If you are on Starter and have been eyeing the frontier models on Elite, this is the closest you have been to them without upgrading. Open the model list, pick GPT-6.1 Sol, and start a session.

Ready to Get Started?

GPT-6.1 Sol is live on Multos Starter and above. Near-Astra intelligence for agentic coding, computer use, and professional work — with a lower error rate and stronger safety behavior. Select it from the model dropdown or let Auto Router pick it for your hardest tasks.

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