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AI Lehel Briefing

Independent signal, primary sources

The important moves in artificial intelligence.

Models, research, coding tools, open source, infrastructure, and major product releases—ordered by publication time.

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Models & research OpenAI

Addendum to o3 and o4-mini system card: Codex

Codex is a cloud-based coding agent. Codex is powered by codex-1, a version of OpenAI o3 optimized for software engineering. codex-1 was trained using reinforcement learning on real-world coding tasks in a variety of environments to generate code that closely mirrors human style and PR preferences, adheres precisely to instructions, and iteratively runs tests until passing results are achieved.