Codex

OpenAI's coding agent in your terminal, IDE and ChatGPT.

Codex reads your codebase, edits files and runs commands from plain-language requests. The CLI is open source; the same agent runs in the desktop app, IDE extensions and ChatGPT on the web.

Key info

Pricing

Open source

Category

CLIs

Related reading

• Prompt engineering

  Prompts that get better code back

  Give it the constraint, not just the goal.

• Fundamentals

  Reviewing code you did not write

  You are going to merge a lot of code you did not type. Reviewing it is a different skill from writing it, and it is the one that actually keeps a vibe-coded…

  Intermediate
• Context engineering

  Why your AI keeps forgetting what you told it

  Models have a context window, a fixed budget of text they can consider at once. Everything competes for it: your instructions, the files you opened, the erro…

  Intermediate

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