Threshold

Mobile-first buyer representation agreement tool for real estate agents.

Setup

1. Firebase

Run flutterfire configure after setting up your Firebase project (see issue #1). The generated lib/firebase_options.dart is gitignored — never commit it.

2. Run the app

Development (no email sending):

flutter run

With email delivery (SendGrid):

flutter run \
  --dart-define=SENDGRID_API_KEY=SG.your_key_here \
  --dart-define=FROM_EMAIL=agreements@yourdomain.com

If SENDGRID_API_KEY is not set, the app runs normally but email delivery is skipped and agreements are marked delivered immediately (useful for UI testing).

3. Environment variables

Never hardcode keys. Pass them at build time via --dart-define:

Variable	Description
SENDGRID_API_KEY	SendGrid API key for email delivery
FROM_EMAIL	Verified sender email address

For production builds, set these in your CI/CD environment.

Architecture

lib/
  core/
    services/
      delivery_service.dart     # SendGrid API call + retry logic
      connectivity_watcher.dart # Auto-retry on network restore
  features/
    auth/          # Firebase Auth login/signup
    agreement/     # Form fill, signature capture, PDF generation
    history/       # Past agreements list

Offline behaviour

PDFs are generated and stored on-device first. Email delivery is attempted immediately and retried automatically when connectivity is restored. The local PDF is preserved until delivery is confirmed.