# Integrations

## Stripe (Connect + Payments)

- **Responsible for:** Card checkout, saved payment methods, walker connected-account onboarding, scheduled payouts, refunds, and webhook-driven payment/payout status updates.
- **Accounts/keys needed:** Stripe account, Stripe API secret + publishable keys, Stripe Connect platform enabled, Stripe webhook signing secret
- **Rough monthly cost at launch scale:** $0/mo base (2.9%+30c per transaction, plus Connect payout fees)
- **Cheaper alternative:** None recommended for marketplace payments; building custom card handling is a compliance and security risk not worth avoiding Stripe's fees.

## Resend (transactional email)

- **Responsible for:** Verification emails, password resets, booking confirmations/reminders, and message notifications.
- **Accounts/keys needed:** Resend account, Resend API key, Verified sending domain
- **Rough monthly cost at launch scale:** $0-20/mo at launch volume
- **Cheaper alternative:** Supabase's built-in email for auth-only flows, though a dedicated provider is needed for booking/message notifications.

## Push notification provider (Expo Push / Firebase Cloud Messaging)

- **Responsible for:** Push notifications for booking status changes and new messages on web/mobile.
- **Accounts/keys needed:** Firebase project + server key, or Expo push credentials
- **Rough monthly cost at launch scale:** $0/mo at launch scale
- **Cheaper alternative:** Email-only notifications at launch, deferring push until user volume justifies it.

## Geocoding provider (Mapbox or Google Geocoding API)

- **Responsible for:** Convert postcodes to lat/lng for radius-based walker search and distance sorting.
- **Accounts/keys needed:** Mapbox account + API token, or Google Cloud project + Geocoding API key
- **Rough monthly cost at launch scale:** $0-25/mo at launch scale
- **Cheaper alternative:** A free postcode-to-coordinates dataset (e.g. UK/US public postal geocode files) loaded into Postgres to avoid per-call API costs.