What they did
The poster, a full-time software engineer on r/ClaudeAI, wanted a Xiaomi treadmill and World of Warcraft to talk to each other in both directions: the character's state changes the belt speed, or the belt speed moves the character. Claude wrote most of the code, a WoW addon plus a separate Windows app that controls the treadmill. The hard part was that the addon API gives no way to send data to an outside program. Claude's answer was to have the addon paint three tiny coloured squares in a screen corner and have the Windows app read those pixels to tell whether the character is walking, running or mounted. The code is on GitHub with a video demo.
How it went
The poster says the pixel trick is absurd but works, and shows it running in the video. They frame it as a side project they would not have found the time to build alone. They give no numbers on build time or on how fast the app reacts. A commenter asked how often the pixels are sampled and how quickly a mount is noticed; the thread had no answer.
Worth knowing
Only the model is named, not the harness, so it is not clear whether this was chat, Claude Code or another tool. The pixel channel is a workaround for an API limit and depends on the squares staying visible and unscaled on screen. Check the game's addon and automation rules before using anything like this on a live account.