Technical Analysis of Codex CLI's Agent Loop Architecture
By
tosh
Crackling crust, pillowy middle. The kind of bagel that earns a second cup of coffee.
Summary
This article provides a technical deep dive into the Codex CLI, a cross-platform local software agent designed for producing high-quality software changes. It's the first post in a series exploring how Codex works, focusing on the agent loop that orchestrates models, tools, prompts, and performance using the Responses API. The article shares insights gained since the CLI's launch in April about building a world-class software agent that operates safely and efficiently on local machines.
Key quotes
· 4 pulledCodex CLI is our cross-platform local software agent, designed to produce high-quality, reliable software changes while operating safely and efficiently on your machine.
We've learned a tremendous amount about how to build a world-class software agent since we first launched the CLI in April.
To unpack those insights, this is the first post in an ongoing series where we'll explore various aspects of how Codex works, as well as hard-earned lessons.
For an even more granular view on how the Codex CLI is built, check out our open source repository at https://github.com/o
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