Event Standard

Executive Summary

Event Standard defines engineering rules for internal events in the Spring Boot Modulith. Events coordinate cross-module workflows and carry business facts that already happened.

Event Rules

Rule	Requirement
Past tense	Event names describe facts that happened.
Source module publishes	The module that owns the fact publishes the event.
Consumers are idempotent	Duplicate delivery must not corrupt state.
Tenant metadata required	TenantId and OrganizationId are required for customer-scoped events.
No source ownership transfer	Consumers react but do not own publisher facts.
Version events	Event contracts require versioning as they evolve.
Audit material events	Important publication and consumption outcomes are auditable.

Event Flow

sequenceDiagram
    participant App as Application Service
    participant Domain as Domain Model
    participant Outbox as Outbox Boundary
    participant EventBus as Internal Event Bus
    participant Consumer as Consumer Module

    App->>Domain: Execute command
    Domain-->>App: Produce domain event
    App->>Outbox: Record event when reliability is required
    Outbox->>EventBus: Publish event
    EventBus->>Consumer: Deliver event
    Consumer-->>Consumer: Process idempotently

Outbox Pattern

The outbox pattern is the future-safe reliability boundary. It should be used for events that coordinate workflows, integrations, analytics, notifications, AIOS, or future external delivery.

Candidate Events

Module	Example Published Events
organization	OrganizationOnboarded, OrganizationProfileUpdated.
compliance	ComplianceEvidenceUploaded, ComplianceRiskRaised.
opportunity	OpportunityDiscovered, OpportunityMatched.
bid	BidWorkspaceCreated, BidApprovalRequested.
intelligence	AIRecommendationProduced, MemoryUpdateProposed.