Locating the source of a mysterious beep
The gist
Developer Simon Willison used Claude Code to build Beep Locator, which found the beep within about 40cm.
The culprit was an old carbon monoxide detector needing new batteries.
How it unfolded
- recentlySomething in Willison's box room, full of boxes still unpacked from his last move, began beeping intermittently.
- Nov 9, 2026Willison published a post describing how he had Claude Code build Beep Locator, using two iPads, a phone, a MacBook Pro and a Surface Ultra as listeners; it placed the beep to within about 40cm, leading him to an old carbon monoxide detector that needed new batteries.
- Nov 10, 2026Willison posted on X asking whether one should open boxes methodically or vibe code software to triangulate the beep; the post had 22.4K views. Hacker News 50 also posted a link to the story on X.
Key terms
- Claude Code
- A series of large language models developed by Anthropic, released as an AI chatbot and used in software development.
- carbon monoxide detector
- A device that senses carbon monoxide gas to help prevent carbon monoxide poisoning.
- triangulate
- To determine the location of a point by forming triangles from known reference points.
Source: Wikipedia