Prescription Meditation
Dr. Stillwell asks what's going on with you, asks a couple of follow-up questions, then prescribes one guided meditation on YouTube, dosed to the time you have.
- Sign in with Google (Firebase Authentication)
- Live AI doctor (Gemini, free tier, through Firebase AI Logic)
- Voice input (the browser's speech recognition: Chrome, Edge, Safari)
- A real video, played in the app (YouTube Data API; optional, it falls back to a YouTube search link)
- Favourites, dislikes and a patient file saved privately per person (Cloud Firestore)
- Repeats a prescription only when your mood is near-identical to an earlier one
One-time setup
1. Firebase (console.firebase.google.com)
- Authentication → Get started → Sign-in method → Google → Enable → Save.
- Firestore Database → Create database → production mode.
- AI Logic → Get started → choose the Gemini Developer API (free).
- Project settings → Your apps → </> (web) → register the app → copy the
firebaseConfig values into .env.local:
VITE_FIREBASE_API_KEY=...
VITE_FIREBASE_AUTH_DOMAIN=...
VITE_FIREBASE_PROJECT_ID=...
VITE_FIREBASE_STORAGE_BUCKET=...
VITE_FIREBASE_MESSAGING_SENDER_ID=...
VITE_FIREBASE_APP_ID=...
2. YouTube key (optional, but it's what makes a specific video play in the app)
- Go to console.cloud.google.com and pick the same project Firebase created.
- APIs & Services → Library → YouTube Data API v3 → Enable.
- APIs & Services → Credentials → Create credentials → API key.
- Edit the key: under Application restrictions choose Websites and add
http://localhost:5173/* and https://thespectrumtechengine.com/*. Under API restrictions allow only YouTube Data API v3.
- Put it in
.env.local as VITE_YOUTUBE_API_KEY=...
The free quota is about 100 prescriptions a day (each costs ~101 units of the 10,000 daily).
Run it on your computer
npm install
npm run dev
Open http://localhost:5173
Put it online
The app is published automatically to https://thespectrumtechengine.com/prescription-meditation/ by GitHub Pages.
Every push to main runs .github/workflows/deploy.yml, which builds the app and publishes it.
The settings from .env.local are stored as repository secrets (Settings → Secrets and variables → Actions),
because .env.local itself is never committed. If you change a key, update the matching secret too.
Google sign-in only works on addresses listed in Firebase → Authentication → Settings → Authorised domains
(localhost and thespectrumtechengine.com).
The database (Firestore, europe-west1) rules live in firestore.rules. After changing them, publish with npx firebase-tools deploy --only firestore:rules.
Before sharing it widely
- Turn on App Check (Firebase console → App Check) so only your site can use your free AI quota.
- The free Gemini tier may use requests to improve Google's products; the sign-in screen says so. Switching the project to a paid plan changes that.
- Each Gemini model has its own small free daily allowance, so
src/doctor.js (CHAINS) spreads requests across several and moves on when one runs out. Adding billing to the Firebase project removes the daily limits.
Growing the app (checklist for when there are more users)
Free limits today, for the whole app per day:
| Limit | Capacity | How to raise it |
|---|
| Gemini AI, free tier (~20 requests per model, 4 models rotate) | ~20 consultations | Upgrade the Firebase project to Blaze (can share the What's 4 the Gaff billing account). Paid tier, no daily cap, ~€0.005–0.01 per consultation. |
| YouTube Data API (10,000 units; ~101 per prescription) | ~99 prescriptions | Not affected by Blaze. Apply (free) via the YouTube API quota extension form well before it's needed. When it runs out, slips show a "Find it on YouTube" link instead. |
| Fraud Defense / App Check | 10,000 checks a month (~100 regular users) | Small charge beyond that. |
Rough budget guide: €15 a month ≈ 1,500–3,000 consultations ≈ 15–35 people using it 3 times every day, or 60–100 typical users.
Before a big launch:
- Upgrade to Blaze and set a budget alert (an alert, not a hard stop).
- Update the sign-in privacy note: on the paid tier Google doesn't use conversations to improve its products.
- Move the free-plan limits (one prescription a day, one swap, one reply afterwards) into Firestore security rules so they can't be bypassed. They're enforced in the app today.
- Request more YouTube quota.
- Optionally simplify
CHAINS in src/doctor.js to always use the best model.
Files
src/doctor.js – Dr. Stillwell's instructions: follow-up questions and the prescriptionsrc/youtube.js – picks the best real video (length, teacher, never one you disliked)src/firebase.js – sign-in, saving, AI connectionsrc/main.js – the screensfirestore.rules – who can read and write what
