The builder’s guide to GPT‑5.6

GPT-5.6 is a new model family designed to deliver high-performance agent capabilities at lower costs than previous generations. The model achieves this through improved efficiency at lower reasoning settings and new API features that allow agents to reuse prior reasoning, run multiple agents in parallel, and handle data processing tasks outside the model's context window. Builders can now select from smaller, cheaper models in the 5.6 family for many workloads while maintaining performance comparable to previous flagship models, or use the larger models with architectural improvements to complete complex tasks with fewer tokens.