Floorplan follows an app’s checkout screen into the code behind it
Floorplan makes a plain-English map of an app, matching frontend requests to backend endpoints across repositories. Its health checks flag common mistakes for review.
The checkout button works, and nobody can explain which server charges the card. Floorplan’s README starts with that uncomfortable gap between having an app and understanding it.
The MIT-licensed project combines Node scripts that trace files and connections with Claude or Codex descriptions. You can start from a familiar screen, then follow its requests into the server and outside services. Recent-work indicators identify parts the agent changed.
Its health checks look for problems including exposed keys, open database rules and fakeable payment webhooks. The project’s own description is admirably short: “A check, not an audit.” A ready-made fix prompt is a lead to investigate; applying it without reading the affected path would recreate the problem the map is meant to solve.
Play the video on YouTubeThe interesting test comes after the next change: can the person maintaining the app explain why the highlighted files had to move together?