Minimal Firebase-hosted backend API has been added using Cloud Functions + Express.

The backend runs on Firebase Cloud Functions (serverless), not on the frontend client.

• Frontend calls HTTPS endpoints

• Cloud Functions reads/writes Firestore + Firebase Auth

• Raspberry Pi device continues using Firestore commands + session/live writes

Base URL after deploy:

https://<region>-<project-id>.cloudfunctions.net/api

Endpoints:

• GET /health

• POST /start body: { "deviceId": "..." }

• POST /end body: { "deviceId": "..." }

• POST /create-user body: { "email": "...", "password": "...", "displayName": "..." }

• POST /sign-up body: same as create-user

• POST /login body: { "email": "...", "password": "..." }

• GET /getAllSessionInfo/:userId

• GET /sessionInfo/:sessionId

• GET /live?sessionId=<id>&limit=200

• GET /live/current?deviceId=<id>

• PATCH /sessionInfo/:sessionId body: { "description": "...", "comments": ["..."] }

Full request/response contracts are documented in docs/api-contracts.md.

For hackathon/demo prep, use the backend seeder to create a demo login and patterned historical sessions:

npm --prefix functions run seed:demo -- --reset

Detailed guide and flags are in docs/demo-data-seeder.md.

• functions/index.js (Express routes)

• functions/package.json

• firebase.json

• .firebaserc

From EngageMint/:

1. Install Firebase CLI (if not installed): npm i -g firebase-tools

2. Login: firebase login

3. Install function deps: npm --prefix functions install

4. Set login API key (needed for /login):

   • Emulator/local: export env var before run

   • Deploy: firebase functions:secrets:set FIREBASE_WEB_API_KEY

5. Deploy: firebase deploy --only functions

From EngageMint/:

• npm --prefix functions install

• firebase emulators:start --only functions

Local base URL:

http://127.0.0.1:5001/<project-id>/us-central1/api

Per request, this is a minimal no-auth middleware API for now.

If you want, next iteration can add token verification and role-based access with minimal route changes.