How Codex Happened: inside OpenAI's coding comeback from failed launch
dkundel · x · 2026-10-16
Dan Shipper's long read retraces Codex's origin: the night before GPT-5's launch in summer 2025, Every's team—given early access a month prior—was underwhelmed by its coding performance. Codex was then a scrappy 'AI software engineer' effort; its earlier cloud version had missed product-market fit and the team was mid-pivot to a local terminal agent.
The piece reveals messy early days: nobody initially mained Codex, and without a code editor even small edits required agent conversations—DX engineer Dominik Kundel complained in Slack that prompting Codex to replace a sentence felt cumbersome. Today Codex anchors OpenAI's comeback, swallowing ChatGPT from within and becoming the foundation for what the company builds next.
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