NEW ChatGPT Code 5.3 Update

OpenAI has officially launched GPT-5.3 Codex, a model that "built itself."

This update moves beyond simple autocomplete to full-scale agentic

engineering. In its first major benchmarks, GPT-5.3 crushed the competition

on SWE-Bench Pro (56.8%) and Terminal-Bench 2.0 (77.3%), showing a

massive jump in its ability to navigate a terminal and handle multi-file legacy

codebases.