Heatmap color-codes every diff line/token by how much human attention it probably needs. Unlike PR-review bots, we try to flag not just by “is it a bug?” but by “is it worth a second look?” (examples: hard-coded secret, weird crypto mode, gnarly logic).
To try it, replace github.com with 0github.com in any GitHub pull request url. Under the hood, we clone the repo into a VM, spin up gpt-5-codex for every diff, and ask it to output a JSON data structure that we parse into a colored heatmap.