Read Model Standard

Purpose

The Read Model Standard defines implementation-level rules for query projections.

Read Model Types

Type	Purpose
Domain read model	Query view owned by one module.
Workflow read model	Task, approval, deadline, or process view.
Cross-domain projection	Governed view combining references from multiple modules.
Mobile read model	Compact view optimized for mobile experiences.
Analytics projection	Reporting projection owned by Analytics.

Rules

• Read models are not source facts.
• Read models have explicit owner, source domains, and lineage.
• TenantId and OrganizationId are required where source data is tenant-scoped.
• Staleness and refresh behavior must be documented.
• Read models should be rebuildable where practical.
• Corrections happen in source domains, then projections update.
• Read model writes are performed by projection builders or owning module services, not arbitrary consumers.

Projection Flow

flowchart LR
    Source[Source Domain]
    Event[Domain Event]
    Projection[Projection Builder]
    ReadModel[(Read Model Table)]
    API[Query API]

    Source --> Event
    Event --> Projection
    Projection --> ReadModel
    ReadModel --> API

Required Spec Fields

• Owner.
• Source domains.
• Source events or read contracts.
• Tenant and organization scope.
• Refresh strategy.
• Rebuild strategy.
• Data freshness metadata.
• Security and entitlement behavior.