Cart App

Shopping cart, checkout, and order management service for the Rose Ash cooperative.

Architecture

One of five Quart microservices sharing a single PostgreSQL database:

App	Port	Domain
blog (coop)	8000	Auth, blog, admin, menus, snippets
market	8001	Product browsing, Suma scraping
cart	8002	Shopping cart, checkout, orders
events	8003	Calendars, bookings, tickets
federation	8004	ActivityPub, fediverse social

Structure

app.py                  # Application factory (create_base_app + blueprints)
path_setup.py           # Adds project root + app dir to sys.path
config/app-config.yaml  # App URLs, SumUp config
models/                 # Cart-domain models (Order, OrderItem, PageConfig)
bp/
  cart/                 # Cart blueprint
    global_routes.py    #   Add to cart, checkout, webhooks, return page
    page_routes.py      #   Page-scoped cart and checkout
    overview_routes.py  #   Cart overview / summary page
    services/           #   Business logic
      checkout.py       #     Order creation, SumUp integration
      check_sumup_status.py  #  Payment status polling
      calendar_cart.py  #     Calendar entry cart queries
      page_cart.py      #     Page-scoped cart queries
      get_cart.py       #     Cart item queries
      identity.py       #     Cart identity (user_id / session_id)
      total.py          #     Price calculations
      clear_cart_for_order.py  # Soft-delete cart after checkout
  order/                # Single order detail view
  orders/               # Order listing view
services/               # register_domain_services() — wires cart + calendar + market
shared/                 # Submodule -> git.rose-ash.com/coop/shared.git

Cross-Domain Communication

• services.calendar.* — claim/confirm entries for orders, adopt on login
• services.market.* — marketplace queries for page-scoped carts
• services.blog.* — post lookup for page context
• shared.services.navigation — site navigation tree

Domain Events

• checkout.py emits order.created via shared.events.emit_event
• check_sumup_status.py emits order.paid via shared.events.emit_event

Checkout Flow

1. User clicks "Checkout"
2. create_order_from_cart() creates Order + OrderItems
3. services.calendar.claim_entries_for_order() marks entries as "ordered"
4. emit: order.created event
5. SumUp hosted checkout created, user redirected
6. SumUp webhook / return page triggers check_sumup_status()
7. If PAID: services.calendar.confirm_entries_for_order(), emit: order.paid

Running

export DATABASE_URL_ASYNC=postgresql+asyncpg://user:pass@localhost/coop
export REDIS_URL=redis://localhost:6379/0
export SECRET_KEY=your-secret-key

hypercorn app:app --bind 0.0.0.0:8002