OpenAI Launches GPT-5.6 Family: Sol, Terra, and Luna
OpenAI
OpenAI released the GPT-5.6 model family on July 9: Sol ($5/$30 per 1M tokens, flagship, tops Terminal-Bench 2.1 at 91.9%), Terra ($2.50/$15, balanced), and Luna ($1/$6, budget). All three are available in ChatGPT, Codex, and the API. The release includes a new 'ultra' effort setting that coordinates parallel agent workstreams for complex tasks.
Why it matters
GPT-5.6 Sol is OpenAI's strongest model to date with expanded agentic and reasoning capabilities; the three-tier structure directly competes with Anthropic's Fable/Sonnet/Haiku lineup at similar or lower cost.
Importance: 5/5
OpenAI flagship model family release, SOTA on agentic coding benchmarks, multi-source official+media confirmation