GPT-5.3-Codex: a new agent for technical tasks

GPT-5.3-Codex is a Codex-native agent that combines advanced coding capabilities with general reasoning. The goal is to support complex and long-term technical tasks in the real world.

This new agent promises to significantly improve efficiency in developing technical solutions, thanks to its ability to handle both the implementation phase (the actual programming) and the high-level design and reasoning phase.

For those evaluating on-premise deployments, there are trade-offs to consider carefully. AI-RADAR offers analytical frameworks on /llm-onpremise to evaluate these aspects.