What a review card is A review card is a single, self-contained item in a review queue. In the “Codex Runs My Inbox Now” material, an inbox-sweep app turns a pile of email into a queue of review cards that a person can approve in seconds. The card bundles what the agent did (or proposes to do) so a human can evaluate it at a glance without opening the original message or re-running the workflow. How it shows up in the workflow The cards sit at the heart of the app's core loop: the agent processes raw email, produces review cards from that work, and the user sweeps through the queue approving cards quickly. Review cards are the point where the automated pipeline meets human judgment — you explore the queue, decide card by card, and move on. The video page frames the whole build as a way to understand how agents can sit inside everyday work, with review cards as the approval surface. Worth considering Before connecting a live inbox, the material flags open risks worth thinking through — review cards are only as trustworthy as the agent output they summarize, so what each card shows (and what it leaves out) matters.