Coffee House Island — Consumer Endpoint¶

The Coffee House is the consumer endpoint of the supply chain. It is intentionally lean: no ERP, no Kafka, no Fabric peer node. A real coffee house has no IT department. Its three software modules can run on one machine or on separate hardware.

→ Architecture overview | Lab Cloud | Hyperledger Fabric

Hardware¶

Component	Function
Linux PC	Runs POS module and optionally Traceability Display
RFID / barcode scanner	Goods receipt (incoming bags) and optionally customer receipts
Customer-facing display	Traceability Display web application
Smart coffee machine + sensors	Reports grind, temperature, bean type, water volume, hardness, extraction time

Three Independent Software Modules¶

Module	Function	Connects to
POS Module	Sales, goods receipt (RFID scan → Distributor REST call), reorders	Distributor REST API
Traceability Display	Shows full batch history + brew parameters to the customer	Lab Cloud (Fabric Gateway + IoT REST)
IoT Connector	Coffee machine sends sensor data via MQTT/serial	Lab Cloud IoT backend

The modules communicate with each other via local REST endpoints and are loosely coupled — each can be developed, deployed, and replaced independently.

What the Coffee House Does NOT Have¶

Not present	Reason
ERP system	A real coffee house doesn't have one
Kafka / internal message broker	No need for event streaming at this scale
Hyperledger Fabric peer node	Read-only access via Lab Cloud Fabric Gateway is sufficient
Local IoT processing	Delegated to Lab Cloud — analogous to a managed cloud service

Traceability Flow¶

Customer orders a coffee
    ↓
Barista scans bag RFID tag (or customer scans QR on receipt)
    ↓
POS Module retrieves batch_id
    ↓
Traceability Display queries Lab Cloud Fabric Gateway (REST)
    ↓
Display shows:
  ✓ Farm:        Yirgacheffe, Ethiopia, 1850m altitude
  ✓ Factory:     medium roast, 212°C, 11 min
  ✓ Distributor: shipped Vienna depot → this café
  ✓ This cup:    18g grind, 93°C, 28s extraction

Status¶

Planned — POS module, Traceability Display, and IoT connector are not yet implemented.