Rumor: OpenAI GPT-5.6 Series Set for Broader Release

johnseach · x · 2026-07-06

Rumors (unofficial third-party leaks) suggest the GPT-5.6 series was previewed on June 26 and will see a broader release this week. The Sol tier brings higher inference effort and an Ultra mode with sub-agents for long-horizon agentic tasks, showing significant leaps in coding (Terminal-Bench SOTA), scientific reasoning, biology, and cybersecurity. Terra matches GPT-5.5 performance at about half the cost, while Luna is the fastest and cheapest tier. Prompt caching has also been improved.

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