One of the biggest unlocks in Codex UX seems to be workflow craft: lightweight house rules in AGENTS.md, auto-cleanups, compaction, and background execution. Great agent products feel steerable.

Conversation over plan mode:

Plan mode creates more slop than actually iterating through the design, data model and interfaces through a conversation with the model.

House rules as behavior shaping:

one of the best things about GPT 5.4 is that it'll just clean up random parts of your codebase as you work with it, purely because it saw a rule in the AGENTS md file

Background execution:

I'm having Codex build something with doom in the background while I'm doing chores and just jumped when I suddenly heard shots and grunting. Turned out Codex was testing the game

Product ambition:

You can truly, build anything