Codex extension on Cursor review:

It's 80% there, and a great way to extend Cursor's usage plan if you already have ChatGPT Plus.

It has all the main UI things: model selector, reasoning level selector, chat/agent modes, % of context window filled, remaining credits.

The last 20% are little things that make it feel like a second-class citizen, such as:

- It replaces the traditional sidebar instead of being a separate one like Cursor's agent.
- You cannot go back to past messages in the conversation and roll back all changes from that point.