OpenAI’s GPT-5 Codex is here

What's under the hood?

By Chantal Kapani

September 16, 2025

Estimated reading time: 3 minutes

Everything engineering teams need to know about OpenAI’s latest AI coding assistant enhancements

OpenAI has released GPT-5 Codex, with the latest version of the agentic coding assistant designed to take on more complex development tasks, from building projects end-to-end, to reviewing code changes. The updates look to bring its capabilities up to speed with GitHub’s May update for its own Copilot coding assistant.

Here’s what’s new, and what it means for engineering teams.

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About the author

Chantal Kapani

Chantal is a staff writer at LeadDev, exploring emerging trends and telling stories that spark meaningful conversations in software leadership.

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OpenAI’s GPT-5 Codex is here

By Chantal Kapani

Your inbox, upgraded.

Join LeadDev.com for free to access this content

About the author

Chantal Kapani

New York

Berlin

London

Meetups

OpenAI’s GPT-5 Codex is here

By Chantal Kapani

Your inbox, upgraded.

Join LeadDev.com for free to access this content

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