changemaker.lite/SERVICE_INTEGRATIONS.md

Service Integrations — EventBus Architecture

Tracking document for the platform-wide EventBus and service integration work.

Started: 2026-03-30 Branch: v2

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Architecture Overview

Changemaker Lite has 30+ services but most operate as isolated tools. The EventBus provides a centralized, typed, in-process pub/sub system that decouples event producers from consumers.

Service Handler (shift created, donation completed, etc.)
        |
        v
  eventBus.publish('shift.created', payload)
        |
        +-- ListmonkListener      (newsletter sync)
        +-- RocketChatListener    (team notifications)
        +-- CrmActivityListener   (contact timeline)
        +-- CalendarSyncListener  (unified calendar)
        +-- N8nWebhookListener    (external automation)
        +-- GancioSyncListener    (public event calendar)

Why In-Process EventEmitter (not Redis PubSub)

• Single Express process — no distributed coordination needed
• Zero serialization overhead (pass JS objects directly)
• Data already persisted in DB — events are ephemeral notifications
• Matches the existing fire-and-forget pattern used by Listmonk/RC services
• Can be swapped to Redis PubSub later if we go multi-process

Key Files

File	Purpose
api/src/types/events.ts	Typed event catalog (all event names + payloads)
api/src/services/event-bus.service.ts	Core EventBus (publish/subscribe/stats)
api/src/services/event-listeners/listmonk.listener.ts	Listmonk newsletter sync
api/src/services/event-listeners/rocketchat.listener.ts	Rocket.Chat notifications
api/src/services/event-listeners/crm-activity.listener.ts	CRM ContactActivity writer
api/src/services/event-listeners/calendar-sync.listener.ts	Calendar unification
api/src/services/event-listeners/n8n-webhook.listener.ts	n8n automation bridge
api/src/services/event-listeners/gancio.listener.ts	Gancio event sync

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Progress Tracker

Phase 1: Core Infrastructure

• Explore existing event patterns (Listmonk, RC, Gancio, provisioning)
• Design EventBus architecture
• Implement EventBus service (api/src/services/event-bus.service.ts)
• Define typed event catalog (api/src/types/events.ts — 46 events across 14 modules)
• Register EventBus in server.ts startup
• Add EventBus stats endpoint (GET /api/observability/event-bus)

Phase 2: Migrate Existing Integrations

• Listmonk event sync → EventBus listener (9 event subscriptions)
• Rocket.Chat webhook service → EventBus listener (4 event subscriptions)
• Gancio shift/event sync → EventBus listener (3 event subscriptions)

Phase 3: New Listeners

• CRM Activity auto-generation listener (11 event subscriptions)
• Calendar sync listener (8 event subscriptions)
• n8n webhook emitter listener (wildcard subscription, forwards all events)
• Listmonk webhook receiver (inbound: open, click, bounce, unsubscribe → EventBus)

Phase 4: Wire Up Publishers (migrated from inline calls)

• Shift CRUD + signup (shift.created/updated/deleted, shift.signup.created/cancelled)
• Canvass session complete + visits (canvass.session.completed, contact.address.updated)
• Response submit (response.submitted)
• Campaign email sent (campaign.email.sent)
• Payment/donation/subscription events (3 event types)
• Contact tag changes (contact.tags.changed — 3 call sites)
• Reengagement sent (reengagement.sent)
• Campaign CRUD + publish + moderation (campaign.created/updated/deleted/published/status.changed)
• User create/update/delete/approve (user.created/updated/deleted/approved)
• SMS campaign start/complete + message send/receive (4 event types)
• Media video publish/unpublish/view (3 event types)
• Ticketed event publish/cancel (EventBus publishes alongside existing Gancio calls)
• Impact story publish (social.impact-story.published)
• Meeting create/delete (jitsi.routes.ts — meeting.created, meeting.deleted)

Phase 4b: Extended Listeners (2026-03-31)

• RC listener: +7 subscriptions (campaign.published, donations, subscriptions, SMS escalation, user.approved, video.published, ticketed-event.published)
• CRM listener: +2 subscriptions (subscription activated, email bounced)
• RC webhook service: +7 new formatter methods
• Prisma migration: SHIFT, MEETING, TICKETED_EVENT added to CalendarItemSource enum
• Calendar sync listener: uses proper source types (SHIFT, MEETING, TICKETED_EVENT)

Phase 5: Future

• Migrate remaining Gancio calls (ticketed-events, meeting-planner) to EventBus
• Add engagement scoring listener
• Add Homepage dashboard data listener

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Event Catalog

Currently Wired (11 event points, 3 consumers)

Event	Listmonk	Rocket.Chat	Gancio
shift.signup	yes	yes	-
shift.signup.cancelled	-	yes	-
shift.created	-	-	yes
shift.updated	-	-	yes
shift.deleted	-	-	yes
canvass.session.completed	yes	yes	-
canvass.address.updated	yes	-	-
campaign.email.sent	yes	-	-
response.submitted	-	yes	-
subscription.activated	yes	-	-
donation.completed	yes	-	-
product.purchased	yes	-	-
contact.tags.changed	yes	-	-
reengagement.sent	yes	-	-

New Events (49+ handlers need publishers)

Event	CRM Activity	Calendar	RC	n8n
campaign.created	-	-	-	yes
campaign.published	-	-	yes	yes
campaign.status.changed	-	-	yes	yes
user.approved	-	-	yes	yes
user.created	-	-	-	yes
video.published	-	-	yes	yes
video.viewed	yes	-	-	-
sms.message.received	yes	-	yes*	yes
sms.campaign.completed	-	-	yes	yes
ticketed-event.published	-	yes	-	yes
meeting.created	-	yes	-	-
impact-story.published	-	-	yes	yes
shift.created	-	yes	-	yes
donation.completed	yes	-	yes	yes
subscription.activated	yes	-	-	yes

*SMS escalations (QUESTION/NEGATIVE sentiment) to relevant RC channel

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Design Decisions

1. Listeners self-guard: Each listener checks its own feature flag (ENABLE_CHAT, LISTMONK_SYNC_ENABLED, etc.) — the EventBus doesn't filter
2. Error isolation: Each listener wraps its handler in try-catch; one listener failing doesn't affect others
3. No persistence: Events are ephemeral — if the server restarts mid-event, it's lost (data is already in DB)
4. Stats tracking: EventBus tracks per-event emission counts + per-listener execution counts for observability
5. Wildcard subscriptions: Listeners can subscribe to shift.* to catch all shift events