Announced Feb 12, 2026, as the specialized ‘fast’ reasoning model.nnKey FeaturesnOptimized for real-time coding suggestions and low-latency agentic tasks where the full GPT-5.3 would be too slow.nnUse CasenUsed in IDE extensions and real-time support agents that need to process logic at lightning speeds.nnWhy Choose Spark?nIt provides a balance of high-level reasoning and extreme speed, making agents feel instantaneous and responsive.