Ha, finally found time to get it working. Yeah it's more hassle than Claude Code since this needs a separate daemon server, but not very bad.

1. Install another copy of codex in a special dir on the Linux machine:

  $ curl -fsSL https://chatgpt.com/codex/install.sh | sh

2. Run codex remote-control from that special dir to start and pair the daemon:

  $ ~/.codex/packages/standalone/current/codex remote-control start

  $ ~/.codex/packages/standalone/current/codex remote-control pair

3. On the phone, open ChatGPT app, Choose Remote, then pair it with the code printed above.

4. Voila! The codex sessions running on the Linux machine now show up on the phone!