Domain Events Overview

Why This Exists

This document explains how domain events support communication across the Algosure Domain Model.

Owner

The owner is the Chief Product Officer and Enterprise Architect.

Business Value

Domain events allow Algosure domains to collaborate without sharing ownership. They support workflow automation, notifications, analytics, AI reasoning, auditability, and modular implementation.

Event-Driven Principle

A domain event records that something meaningful happened inside an owning domain.

Examples:

• OrganizationRegistered.
• ComplianceDocumentExpiring.
• OpportunityMatched.
• BidWorkspaceCreated.
• ContractMilestoneCompleted.
• LearningRecommendationCreated.
• NotificationDelivered.
• MetricSnapshotCreated.
• SubscriptionPastDue.
• AuthorizationDecisionRecorded.
• FeatureFlagUpdated.

Event Communication Model

sequenceDiagram
    participant Source as Owning Domain
    participant EventBus as Event Mesh
    participant Notification
    participant Analytics
    participant Intelligence
    participant Consumer as Other Domain

    Source->>EventBus: Publish domain event
    EventBus-->>Notification: Communication trigger
    EventBus-->>Analytics: Reporting input
    EventBus-->>Intelligence: Reasoning input
    EventBus-->>Consumer: Workflow trigger
    Consumer->>Consumer: Apply own rules before state change

Event Metadata Standard

Every cross-domain event should include:

• EventId.
• EventType.
• SourceDomain.
• AggregateId.
• AggregateType.
• OccurredAt.
• OrganizationId where applicable.
• ActorId where applicable.
• CorrelationId.
• CausationId.
• SchemaVersion.

Event Ownership Rules

• The source domain owns event meaning.
• Consumers own their reaction.
• Events must not expose internal implementation details.
• Events must not require consumers to mutate source state.
• Events should carry enough context to route and evaluate, not enough to duplicate entire aggregates.

Common Event Consumers

Consumer	Typical use
Notification	Creates notification requests, reminders, and escalations.
Analytics	Creates snapshots, reporting models, trends, and insights.
Intelligence	Interprets events, explains changes, and supports recommendations.
Learning	Creates learning recommendations from gaps or operational patterns.
Administration	Opens support, review, or governance workflows.
Identity	Responds to access-related configuration and membership changes where appropriate.

Event And Command Distinction

Events say what happened. Commands request something to happen.

Example:

• Event: PaymentFailed.
• Command: RequestBillingNotification.

This distinction protects ownership because consumers do not treat every event as permission to mutate another domain's facts.

Spring Boot Modulith Alignment

Spring Boot Modulith supports application events and module boundary verification. Algosure should use domain events to express module collaboration and use tests to ensure modules communicate through approved APIs and events.