GuideBeginner
Use Codex to write code on the web with ai agents
The Rundown: In this guide, you’ll learn how to use OpenAI’s “Codex” to ship your first change from a GitHub repository without writing code by hand.
Required tools
None required
Updated
Jan 30, 2026
Guide preview locked
The Rundown: In this guide, you’ll learn how to use OpenAI’s “Codex” to ship your first change from a GitHub repository without writing code by hand. You’ll connect a repo, set an execution environment, plan a change, have the agent implement it, preview the result, and open a pull request (PR)
Who is this useful for:
- Non-developers who want to code with agents
- PMs and founders validating ideas
- Designers turning mockups into code
- Developers prototyping faster
First of all, what is OpenAI Codex?
Codex is OpenAI's version of an AI agent built specifically for coding tasks. Alternatives include Claude Code,...