OpenAI introduced GPT-5.3-Codex-Spark, a new real-time coding model built for rapid interactive development. It generates more than 1,000 tokens per second and supports a 128,000-token context window.
The model runs on specialized low-latency hardware from Cerebras Systems and is available as a research preview for ChatGPT Pro users through the Codex app, CLI, and IDE extension. Codex-Spark focuses on instant feedback and rapid iteration while staying capable on real software engineering tasks.
It expands the Codex family by enabling real-time collaboration alongside longer, deeper reasoning workflows.


