Codex can indeed achieve automatic editing, and the logic is simple: it learns from CapCut’s SKILL, and then you can use all of CapCut’s features.

SKILL:
Of course, it’s not possible to truly match human editing, but the capabilities are already very powerful. Here are some useful ones.
Voiceover: Absolutely useful; otherwise you’d only be able to use the system’s robotic voice.
Subtitles: You can add subtitles in post, and the accuracy is very high. If you provide the subtitles, it can achieve good audio-word alignment.
Sound effects: This is very smart—you don’t need to find them yourself.
BGM: You can also find relatively suitable background music, which is much more convenient than searching on your own.
Transitions: This makes your videos look less disjointed.
With these features combined, you can meet almost all basic editing needs. You can also try it. After you’re done, you can go into CapCut to edit it again yourself.