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 with Kiro profiles in us-east-1 or eu-central-1. All three tiers use global cross-region inference, independently of their Experimental lifecycle status. Requests may be processed in supported commercial AWS Regions worldwide, including Regions outside your Kiro profile's geography, without changing where Kiro stores your content. See the inference endpoint regions table for each model's scope and endpoint. Learn more ->