Running both, in practice

You have two tools installed now. Here's what using both actually looks like on a normal day, so it's concrete and not just an idea.

You don't run them at once

You don't have both going side by side, racing. You have one open at a time, and you switch when there's a reason. Most of a working session is just one tool, the one you opened, doing its job.

The switch moves

Three switches are worth having in your hands:

• The stuck switch. One CLI has tried to fix something three times and it's still broken. Exit it. Open the other one in the same folder. Give it the same problem, and add what you learned: "the error is X, a previous attempt tried Y and it didn't work." A different model often breaks the loop.
• The review switch. One CLI just made a change you're not sure about. Open the other one and ask it, plainly: "look at this file and tell me if anything looks wrong." A second tool reviewing the first is one of the best safety checks you have, and it costs two minutes.
• The outage switch. A tool is down or crawling. The other one is the better tool for the next hour. No loyalty, just whatever works.

Both see the same folder

This is the part that makes switching painless. Both CLIs work on real files in a real folder. They don't have private copies. So when you exit Claude and open Codex in the same folder, Codex sees exactly the current state of the files, including whatever Claude just changed. The folder is the shared ground. The tools are interchangeable visitors to it.

That's the whole workflow. One tool at a time, switch when you have a reason, and let the folder be the thing that's constant.