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How to debug visual bugs with Modaal: Visual bugs — a missing image, a misaligned button, the wrong text on the wrong screen — are the hardest things to describe in code terms. You see them, but you don’t know which file or what to check. Modaal closes that gap by letting the agent see and use your running app. You describe what you see, and the agent debugs it the way an engineer would.

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How to do it

With your project open and the simulator running, describe the bug in plain language. Name the screen where you see it. If there’s another screen where the same thing works correctly, name that too — the contrast is the most useful clue the agent can get. A good prompt looks like this:
The avatar is missing on the Profile tab — I just see a grey circle with my initial. On the Invite screen, the avatar shows correctly. Find and fix it.
That’s it. No file names. No hypothesis.

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What the agent does

On its own, the agent will:
  1. Search your code to find both screens
  2. Read the console logs from the running simulator
  3. Take a screenshot of the broken screen and look at it
  4. Inspect the live UI hierarchy
  5. Write a fix and rebuild the app
  6. Tap to the affected screen in the simulator
  7. Take a new screenshot to verify the fix worked
You don’t open Xcode. You don’t touch the simulator.

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Check the surrounding screens

After the fix, ask the agent to verify nothing else broke:
Check that the Invite screen still works.
The agent taps the Invite button on its own, takes a screenshot, and confirms the avatar is still showing there too. When both screens look right, tell the agent to commit.

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Why this works

Modaal gives the agent a live connection to the iOS simulator — screenshots, console logs, UI hierarchy, and the ability to tap, scroll, and switch tabs. So when the agent says “the fix is verified,” it’s because it looked at the screen, not because the build compiled. That’s the loop a senior iOS engineer runs every day. Visual debugging is how Modaal gives you the same loop without learning Swift.