A small messaging app, built from one sentence. First it becomes a real app with a database and its own address. Then it gets a free AI inside. Then it goes to the App Store. Three steps, each one a real build replayed as it happened.
One sentence becomes Relay. Tested on a phone, saved to a repository, given a real database and secrets, deployed, put on its own address. Two real bugs found and fixed on screen. 15 parts, with a plain-English line under every one.
Relay gets a contact that actually answers, running on a free, open-weight model (gpt-oss on Groq). Rails and scaffolding first: what it may say, what it must refuse, a daily cap, and the key kept out of the app.
The same app, wrapped for iPhone and Android, through TestFlight and review to a store listing. What Apple checks when an app has AI in it, and what "free" means once real people use it.
index.html). Four small server functions (api/) talk to the database. A short schema (schema.sql) made the tables. A seed script filled them through the API. A BUILD_LOG.md records every change and why. Private repository, own deploy, own address.