0002. Offline-first

• Status: Accepted
• Date: 2026-10-27

Context

Many Malaysian shops have unreliable internet. A point of sale that stalls at the counter when the connection drops loses sales and trust.

Decision

Taking an order, totalling, paying, printing and closing a shift never wait on the internet or on any remote call. Every device keeps what it needs locally (catalog, staff, its own event log) and syncs in the background when a link is available.

Consequences

• No network call (hub, cloud, telemetry, update check) may sit on the path of taking, paying or printing an order.
• Devices need local storage and their own copy of the domain logic (see ADR 0009).
• Sync must tolerate long offline periods and resent data (see ADR 0004).