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GPT-5.3-Codex

OpenAI releases GPT-5.3-Codex, extending Codex toward broader computer-based professional workflows beyond code generation.

Model Release

What Happened

OpenAI introduced GPT-5.3-Codex, positioning it as a more capable agentic coding model that also expands what Codex can do across computer-based professional work.

Why It Matters

The release captures a key industry inflection point: coding agents evolving into general “computer-using” agents that combine research, tool use, and execution, while remaining steerable during long tasks.

Technical Details