OpenAI GPT-5.6 Sol, Terra, and Luna now available

OpenAI models are available in Kiro for the first time. GPT-5.6 Sol, Terra, and Luna bring three tiers of frontier intelligence to the IDE, CLI, and Web — each tuned for a different point on the performance-cost curve. Sol is the flagship, built for the hardest multi-step work: spec-driven implementation, long-horizon refactors, and complex terminal tasks. It scores 80 on the Coding Agent Index and 88.8% on Terminal-Bench 2.1. Terra is the balanced option for routine multi-step development at a fraction of flagship cost. Luna is the fastest, lowest-cost tier for high-frequency tasks where throughput matters most. All three run longer without supervision and can write lightweight programs that coordinate tools and process intermediate results, reducing round-trips and dead ends. Hidden chain-of-thought means you see final output only. 272K context window across all tiers. Kiro credit multipliers: Sol 2.4x, Terra 1.2x, Luna 0.6x. Experimental support is rolling out to Pro, Pro+, Pro Max, and Power customers in us-east-1 and eu-central-1 with cross-region inference. Learn more ->