GPT-5.6

OpenAI · July 2026

activeClosedmixture of expertsmultimodal
VariantsSol, Terra, Luna

Why It Matters

First frontier model subjected to rigorous US government review prior to launch. Reestablished OpenAI's position at the edge of the cost-performance curve.

Description

OpenAI's frontier model family (Sol, Terra, Luna) offering significant improvements. First model to undergo customer-by-customer US government review before launch.

Key Innovations

Agentic
AgenticModels that can autonomously plan, execute multi-step tasks, use tools, and self-correct without human intervention.
Reasoning
ReasoningStructured step-by-step problem solving, often using chain-of-thought or tree-of-thought approaches.

Related Research (1)

Ten Advances in Mathematics and Theoretical Computer ScienceReasoning
2026 · OpenAI

Showcased AI solving complex mathematical problems with Lean-formalized proofs, achieving breakthroughs in problems that had seen no progress for deca…