Codex is OpenAI's agent form for coding, different from a chat page: one mode edits code conversationally in a project directory from the terminal, another hands the task to a cloud job that reads the repo in an isolated environment, writes changes and tests, and returns for review. It handles complete engineering tasks, so state goals, limits and acceptance clearly. Cloud jobs take time; review diffs and test output before merging.
What it does
- Reads and writes the current repo from terminal or editor
- Cloud jobs run asynchronously in an isolated environment
- Connects to code repos and works from project context
- Writes tests alongside changes to judge usability
- Delivers reviewable patches or branches
Who it is for
- A clear technical task to run and review in one pass
- Backlogged refactors, dependency upgrades and test gaps
- Sending work to the background instead of watching it
- Locating consistent change points across related files
How to get started
- Try a small change on a non-critical branch from your local terminal
- Write requirements in three parts: goal, limits, acceptance
- Review diffs and test output before merging cloud work
