First Chair Prep

A home-screen app for a 10-week ski conditioning plan (Oct 8 – Dec 15, 2026). Static files only: no build step. Vercel hosts it. Supabase stores your log and syncs it across devices.

Files

File	What it does
index.html	The whole app (plan, views, sync)
config.js	Your Supabase URL and key. Edit this.
manifest.webmanifest	App name, icon, full-screen mode
sw.js	Offline cache
icons/	Home-screen icons
supabase/schema.sql	Database table and security rules
vercel.json	Cache headers

1. Set up Supabase (10 min)

1. Go to supabase.com → New project. Pick a name and a region near you (for example, West US). Save the database password somewhere safe.
2. Open SQL Editor → New query. Paste all of supabase/schema.sql and click Run.
3. Open Authentication → Emails → Magic Link (the template name can be "Magic link" or "Confirm sign in"). Replace the body with:

   <h2>Your First Chair code</h2>
   <p>Enter this code in the app: <strong>{{ .Token }}</strong></p>
   

   The app signs you in with a code, not a link. A link opens Safari, and on iPhone a home-screen app does not share sign-in with Safari.
4. Open Project Settings → API. Copy the Project URL and the anon public key (or the publishable key). Paste both into config.js.

2. Deploy to Vercel (5 min)

Option A: GitHub (best for updates)

1. Make a new GitHub repo and push this folder to it.
2. On vercel.com → Add New → Project → import the repo.
3. Framework preset: Other. Leave the build command and output directory empty. Click Deploy.
4. Each later git push deploys again.

Option B: Vercel CLI

cd first-chair-app
npx vercel        # first time: log in and accept the defaults
npx vercel --prod

3. Finish Supabase auth settings

1. Authentication → URL Configuration → Site URL: paste your Vercel URL (for example https://first-chair.vercel.app).
2. Open the app, tap Sign in to sync, and sign in once with your email.
3. Then go to Authentication → Sign In / Providers and turn off "Allow new users to sign up". Now only you can use your database.

4. Install on your phone

• iPhone: open your Vercel URL in Safari → Share → Add to Home Screen. Open the app from the icon and sign in again (the home-screen app has its own storage).
• Android: open it in Chrome → menu → Install app.

How sync works

• Every tap saves on the device first, so the app works with no signal.
• When you are online and signed in, changes go to Supabase about one second later. The app also syncs when you open it or come back to it.
• If the same day changes on two devices, the newest change wins.

Updating the app

1. Edit the files.
2. In sw.js, change VERSION (for example fc-v1 → fc-v2).
3. Deploy. Close the app fully and open it again to load the new version.

Limits to know

• The free Supabase email sender allows only a few emails per hour. That is enough for one person.
• Free Supabase projects pause after about a week with no activity. Daily use keeps it awake. If it pauses, restore it from the dashboard. Your data stays.