Developer Builds Lumi With Claude Code: A Free Spotlight With AI for Mac and Windows

A developer who used to open Spotlight every day and then switch to a browser to ask an AI model a question has merged both actions into a single input line. The app is called Lumi. It is free, open source and runs on two platforms: macOS and Windows. Press a key and type a query. If it's a file or a program, it opens. If it's a question, an AI model answers. The author wrote Lumi together with the AI assistant Claude Code.

The two-window problem

The original motivation is very mundane. Spotlight is good at searching and launching, but it won't answer a question like "how do I rename a branch in git." For that, there is a chatbot in a browser tab. So a single intent, "I need something quickly," requires two interfaces and two context switches. The author decided to close that gap and build a single entry point.

The idea is not new. On the Mac, launchers such as Raycast with AI features occupy a similar niche, and Windows has PowerToys Run. But Lumi has its own set of differences: it is free, its code is open, and it behaves the same on both systems.

What we know about Lumi

Based on the available excerpt, the announcement on Habr does not yet disclose detailed specifications. The main facts are these:

• platforms: macOS and Windows;
• license and price: free, source code open;
• interface: a single input line summoned with a hotkey;
• features: file search, program launching, answers to questions via an AI model;
• development: the author worked together with Claude Code, and a detailed account is promised at the end of the article.

What the announcement does not say: which model answers the questions, whether it runs locally or through a cloud API, and who pays for the requests. For a free app, the last point is key. Users will probably have to supply their own API key or connect a local model, but that is an assumption, not a confirmed fact. The routing logic is not described either: how Lumi decides whether it is looking at a file name or a question.

Claude Code as co-author

The development method itself is of particular interest. The author states directly that he did not build Lumi alone but in tandem with Claude Code, Anthropic's coding assistant. A cross-platform desktop tool with global hotkeys, a file index and model integration usually means wrestling with the system APIs of two operating systems. That makes the project a good illustration of how much routine work coding agents take on. The author moved the details to the end of the article: what exactly the assistant did, where it made mistakes and how many corrections were needed. That part will probably be the most useful for developers.

What to try

If you constantly switch between a launcher and a chatbot, Lumi is worth installing and comparing against your current setup. Check three things before installing. First, where the model comes from and where your queries go: a search bar sees file names, so privacy here is not a formality. Second, how search performs on a large disk. Third, how the app behaves with multiple monitors and different keyboard layouts.

Because the code is open, you can read it and verify which data leaves your computer. And the author's article is worth reading to the end: it can help you judge whether the "human plus Claude Code" approach suits your own small utilities.