IoT parking flow built around confirmed payment before gate release.
OpenIt coordinates hardware events, payment confirmation, and gate release in one flow. The gate opens only after the backend persists webhook-confirmed payment state.
Node-RED keeps hardware orchestration out of backend application code.
Payment context owns webhook persistence and the terminal status stream.
Gate release depends on stored payment state instead of optimistic client state.
Hardware state advances only after webhook-confirmed payment, not after optimistic UI feedback.
team of three across firmware, backend, and interface
access and payment contexts with separate rules and storage
server-pushed payment confirmation without polling
Device events travel through MQTT and Node-RED, the backend separates access from payment state, and gate release happens only after webhook-confirmed payment.
Hardware cannot trust optimistic UI state because payment truth lives in backend state.
The gate opens only after confirmed payment becomes persisted application state.
ESP32 devices publish events through MQTT, Node-RED translates them into backend actions, and the backend keeps access and payment in separate contexts. Mercado Pago confirmation persists first, SSE updates the terminal, and only then does the open-gate command leave the system.
Confirmed webhook state over optimistic gate release
Opening the gate when the UI says payment started lets hardware behavior drift away from persisted business state. OpenIt waits for the Mercado Pago webhook to persist confirmation before releasing the exit flow.
Node-RED orchestration over backend-to-device coupling
Talking to ESP32 devices directly from the backend mixes hardware protocol concerns into the application service layer. Node-RED handles MQTT orchestration so the backend stays focused on access and payment rules.
SSE updates over client polling
Client polling adds repeated reads, slower feedback, and more edge cases when payment status changes quickly. SSE lets the backend push confirmation as soon as the webhook lands.
Bounded contexts over one merged parking module
One merged parking module blends gate rules with payment rules and makes every change touch the same service logic. OpenIt keeps access and payment separate so each flow can evolve around its own state transitions.