I Had Claude Code Check My Waybar Fix: AT-SPI Could See the Button but Not Press It

I tried to have Claude Code check that a Waybar fix had worked, not just apply it. That is how I learned the desktop has a way to read the UI apart from the screen: the accessibility tree. Waybar's workspace buttons could not be pressed through it, though. In the end I pressed them myself.

Waybar, left alone

Waybar had bothered me for a while. Clicking a workspace button did not switch workspaces, and the Wi-Fi access point I was connected to showed wrong. I knew, and left it.

Then I felt like fixing it. I had Claude Code look at upstream: a PR that fixes the workspace commands for Hyprland's Lua config (#5013) had been merged. So I had it build waybar-git from the AUR and swap it in.

Having Claude Code check the fix

With the git version in, the next step was checking that it worked. I wondered if Claude Code could do that too: press a button and see whether the workspace switches.

Without taking a screenshot, Claude Code walked at-spi2-core's accessibility tree over D-Bus and listed Waybar's buttons and labels.

I didn't know this existed. Given the idea of separating the API from the view, maybe it's obvious, but I hadn't thought the desktop worked that way too. I learned something.

Visible, but it won't press

If it can see the button, it can press it, I thought, and had it run the AT-SPI Click action on a workspace button. Nothing switched. No error either.

I had Claude Code read Waybar's src/modules/hyprland/workspace.cpp. The button is built like this:

m_button.add_events(Gdk::BUTTON_PRESS_MASK); ... m_button.signal_button_press_event().connect(sigc::mem_fun(*this, &Workspace::handleClicked), false); 

The switch itself, handleClicked, runs only from a mouse button press event. Claude Code's explanation was that AT-SPI's Click does not raise that event, so it misses. I haven't checked this myself, and the code it read is today's upstream, which may differ from the revision I built.

I pressed it myself

I did the check by hand. The workspaces switched, and the Wi-Fi access point now showed correctly.

The check didn't get automated. Still, finding out that there is an API behind the screen that reads the UI was worth it.

This post was written with AI assistance and reviewed by the author.