After seeing people use Claude Code inside Home Assistant, I thought, why not build a proper Codex CLI add-on? The add-ons I found either didn't work or lacked the desired functionality.
So, I built (probably another) Codex CLI for Home Assistant with a Home Assistant-style UI, a persistent terminal session, an auth.json upload (since logging in via link doesn't work), image paste support (which also doesn't work as expected) and reload yaml configuration + HA restart buttons.
To authenticate, log in to Codex on your computer, retrieve the auth.json file (treat this as a password!) and upload it (will be stored inside Codex add-on's private /data volume).
To modify the UI, ask Codex to switch to YAML mode. This will create a ui-lovelace.yaml. However, you will lose the ability to design your UI with the UI designer in the browser!
Add this via http://<HA-IP>:8123/config/apps/repositories and install the app:
Repo: https://github.com/npinter/codex-cli-ha
For me it's working great so far using GPT-5.5 med/high. Would love to get some feedback (PRs are welcome :) )
