I Built My Own RSS Reader in an Afternoon, With AI Doing the Typing A developer built LumenAI, a local-first RSS reader for macOS with AI summaries, in roughly an hour by acting as product owner and build verifier while an AI wrote all the code. The project used a phased spec with explicit non-goals and a human build check-in after each phase, since the AI's Linux sandbox couldn't compile a Mac app, yielding 38 Swift files, 27 tests and no runtime crashes. The AI layer centers on a single SummaryProvider protocol with six implementations, including Apple Intelligence on-device, Ollama, Claude, OpenAI and Gemini, with API keys stored in the macOS Keychain. For years my RSS setup was a compromise. I never wanted to pay for a desktop reader, so I stayed on The Old Reader: a perfectly fine service, but it felt like visiting a website, because that's what it was. What I actually wanted was simple: a native Mac app, feeds stored locally, no account, no subscription, and fast enough to triage a hundred articles from the keyboard. So I stopped wishing and built it. LumenAI is a local-first RSS reader for macOS with AI summaries, taken from an empty folder to a notarizable DMG in about an hour of wall-clock time, with me as product owner and build verifier while the AI wrote the code. My pitch to the AI was one paragraph: a local RSS reader for Mac, a premium feel, and treat it like a real engineering project, with clear phases, and ask me questions before making decisions . That last sentence mattered most. Instead of a wall of code, it interviewed me: stack, what v1 includes, what it excludes, how refresh works, what "premium" means concretely. A few rounds of multiple-choice later we had a spec. Writing down the non-goals felt ceremonial. It wasn't: every time scope tried to creep, that list ended the discussion in one line. Every choice optimised for native feel, local data, no servers. .xcodeproj . The part I'm proudest of is the AI layer: one SummaryProvider protocol with six implementations Apple Intelligence on-device, Ollama, Claude, OpenAI, Gemini, and Disabled . Swapping providers is a dropdown; keys live in the macOS Keychain. for loop.