What changed
GPT-5.6 Sol, Terra and Luna arrived in the Kiro IDE, CLI and Web as experimental models with a 272K context window, at credit multipliers of 2.4× for Sol, 1.2× for Terra and 0.6× for Luna. Access rolled out to paid customers with profiles in us-east-1 or eu-central-1, using global cross-region inference, so requests may be processed outside your profile’s region. Kiro later cut the Terra and Luna multipliers (July 31) and raised the context window to 1M (September 14).
Who it affects
Paid Kiro users, and compliance teams who care where inference runs.
What to do
Use Luna or Terra for routine work to save credits, and check the cross-region terms before using them on regulated code.