notification_engine — Zalo ZNS Delivery

The notification engine currently implements Zalo ZNS campaign delivery and Zalo OA token maintenance. It validates approved zalo_zns campaigns, resolves eligible phone recipients, binds typed template parameters, dispatches through the selected adapter, and writes idempotent dispatch-log records.

It also projects Zalo opt-out events from the S3 event lake onto cdp_master_profiles.communication_preferences.

Dagster interface

• zalo_token_refresh_job
• notification_engine_job
• zalo_optout_projection_job
• Schedules: zalo_token_refresh_schedule and zalo_optout_projection_schedule, each every five minutes

The implementation is in notification_engine/. Campaign sends use send_zalo_campaign; token refresh uses refresh_due_tokens; opt-out projection uses project_optout_events.

Package layout

Path	Responsibility
dagster_defs.py	Jobs, ops, schedules, and typed campaign configuration
notification_engine/send.py	ZNS campaign validation, recipient batching, dispatch, and ledger writes
notification_engine/adapters.py	ZNS provider adapter selection
notification_engine/provider_config.py	Tenant-scoped Zalo connector and OA token loading
notification_engine/optout_projection.py	S3-first opt-out event projection
notification_engine/token_refresh.py	Near-expiry OA token refresh
tests/	Pure notification-engine tests

Local development

cd customer360-backend/notification_engine
./run_tests.sh