GPT-5.3-Codex System Card
TL;DR
OpenAI released GPT-5.3-Codex as its most capable coding model yet – combining GPT-5.2-Codex's frontier coding performance with GPT-5.2's reasoning and knowledge.
Key Points
- The model is optimized for agentic coding workflows, enabling autonomous completion of complex programming tasks.
- The system card details technical specs, safety evaluations, and deployment guidelines.
Nauti's Take
Merging reasoning with coding is the logical next step – but OpenAI continues serving marketing crumbs instead of real benchmarks. Model size?
Training data? Cost?
Nothing. The system card reads like a brochure, not a transparent document.
Until we know whether GPT-5.3-Codex genuinely outperforms open-source alternatives like DeepSeek or Qwen-Coder, this remains an announcement without substance.
Sources