OpenAI Launches GPT-5.6 Family (Luna, Terra, Sol) and ChatGPT Work Workplace Agent

What happened

OpenAI launched the GPT-5.6 family (Luna, Terra, Sol) on July 9, 2026, alongside ChatGPT Work — a new agentic product for automating complex workplace tasks. The launch coincided with Anthropic's expansion of Claude Cowork to web and mobile on the same day.

Context and impact

GPT-5.6 Sol scored 53.6 on Agents' Last Exam vs. 40.5 for Claude Fable 5, claiming leadership on agentic benchmarks. GPT-5.6 was also designated as the preferred model in Microsoft 365 Copilot — a strategic counter-signal to reports that Microsoft was replacing OpenAI with its own MAI models. ChatGPT Work is available on web and mobile and can generate reports, presentations, websites, and analyses from a single request.

Details

• GPT-5.6 Sol: most powerful, $5 input / $30 output per million tokens
• GPT-5.6 Terra: balanced default, $2.50 / $15 per million tokens
• GPT-5.6 Luna: fast and cheap, $1 / $6 per million tokens
• Context window: 1 million tokens, February 2026 knowledge cutoff
• New API: programmatic tool calling, multi-agent orchestration, prompt cache breakpoints
• ChatGPT Work launched for Pro, Enterprise, Edu; Plus and Business to follow within days
• GPT-5.6 designated as preferred model in M365 Copilot (Word, Excel, PowerPoint)