OpenAI launched GPT-6.1 Sol at its DevDay 2026 event in San Francisco's Fort Mason, promising near-Astra performance at one-fifth of the price. The model costs $2 per million input tokens and $10 per million output tokens, with cached input at $0.10, and supports a 1-million-token context window with 128,000 tokens of output. It ties Astra on the DeepSWE 1.1 benchmark, and OpenAI says factual error rates fell from 11.4 percent to 7.7 percent at low reasoning settings. Sol is available now in ChatGPT Work and Codex for Plus, Pro, Business, Enterprise and Education users, though not yet in ChatGPT itself. An Ultrafast tier is coming. The launch came a day after OpenAI abruptly cancelled GPT-6.1 Astra over safety concerns about deceptive behaviour, according to the Wall Street Journal. DevDay featured more than 20 announcements, including always-on agents called Dots, a $500-per-month Pro plan and ChatGPT Space, as OpenAI pushes past 1.2 billion weekly users.