AI Model Governance

Background

The EU AI Act (enacted in 2024, fully enforced in 2026) classifies AI systems by risk level and mandates conformity assessments, post-deployment monitoring, and incident reporting for high-risk AI. This example implements the core requirements of the EU AI Act within a single bounded context using DDD tactical patterns and the Functorium framework.

Functorium DDD Example Series

Example	Layer	Domain	Key Learning
designing-with-types	Domain	Contact Management	Value Object, Aggregate Root
ecommerce-ddd	Domain + Application	E-Commerce	CQRS, FinT LINQ, Apply Pattern
ai-model-governance (this example)	Domain + Application + Adapter	AI Model Governance	Advanced IO Features, Observability, Full-stack DDD

This is the third and final example in the series, building on the patterns covered in the Domain/Application layers by adding Adapter layer LanguageExt IO advanced features (Retry, Timeout, Fork, Bracket) and OpenTelemetry 3-Pillar observability.

functorium-develop 7-Step Workflow

This example follows the 7-step workflow of functorium-develop plugin v0.4.0.

Step	Skill	Document	Description
0	project-spec	Project Requirements Specification	PRD: KPIs, Ubiquitous Language, Aggregate Candidates, Acceptance Criteria
1	architecture-design	Architecture Design	Project Structure, DI Strategy, Observability Pipeline
2-4	domain-develop	Domain Track	VO, Aggregate, Domain Service, Specification
2-4	application-develop	Application Track	CQRS UseCase, Port, Event Handler
2-4	adapter-develop	Adapter Track	Repository, External Service, HTTP API
5	observability-develop	Observability Track	Dashboard, Alerts, ctx.* Propagation
6	test-develop	(Test code included)	268 Unit Tests, Integration Tests

Applied DDD Building Blocks

DDD Concept	Functorium Type	Application
Value Object	`SimpleValueObject<T>`, `ComparableSimpleValueObject<T>`	ModelName, ModelVersion, EndpointUrl, DriftThreshold, etc.
Smart Enum	`SimpleValueObject<string>` + `HashMap`	RiskTier, DeploymentStatus, IncidentStatus, AssessmentStatus, etc.
Entity	`Entity<TId>`	AssessmentCriterion (child entity)
Aggregate Root	`AggregateRoot<TId>`	AIModel, ModelDeployment, ComplianceAssessment, ModelIncident
Domain Event	`DomainEvent`	18 types (Registered, Quarantined, Reported, etc.)
Domain Error	`DomainErrorType.Custom`	InvalidStatusTransition, AlreadyDeleted, etc.
Specification	`ExpressionSpecification<T>`	12 types (ModelNameSpec, DeploymentActiveSpec, etc.)
Domain Service	`IDomainService`	RiskClassificationService, DeploymentEligibilityService
Repository	`IRepository<T, TId>`	4 Repository Interfaces

Applied Application Patterns

Pattern	Implementation	Application
CQRS	`ICommandUsecase` / `IQueryUsecase`	8 Commands, 7 Queries
Apply Pattern	`tuple.ApplyT()`	Parallel VO Validation Composition
FinT LINQ	`from...in` Chaining	Async Error Propagation
Port/Adapter	`IQueryPort`, `IRepository`	Read/Write Separation
Event Handler	`IDomainEventHandler<T>`	2 Event Handlers
FluentValidation	`MustSatisfyValidation`	Syntactic + Semantic Dual Validation

Applied Adapter Patterns (Advanced IO Features)

IO Pattern	Implementation Class	Purpose
Timeout + Catch	`ModelHealthCheckService`	Health Check Timeout Handling
Retry + Schedule	`ModelMonitoringService`	External API Retry (Exponential Backoff)
Fork + awaitAll	`ParallelComplianceCheckService`	Parallel Compliance Checks
Bracket	`ModelRegistryService`	Resource Lifecycle Management (Session)

Applied Observability Patterns

Pattern	Implementation	Application
Observable Port	`[GenerateObservablePort]` + Source Generator	Repository 10, Query 5, External Service 4
Pipeline Middleware	`UseObservability()` + Explicit Opt-in	Metrics, Tracing, CtxEnricher, Logging, Validation, Exception
DomainEvent Observability	`ObservableDomainEventNotificationPublisher`	Observing Publication/Handling of 18 DomainEvents
ctx.* Propagation	`[CtxTarget]` + CtxPillar	MetricsTag(2), MetricsValue(1), Default(8+), Logging(2)

Domain Track

Step	Document	Description
0. Requirements	Domain Business Requirements	Business Rules, State Transitions, Cross-Domain Rules
1. Design	Domain Type Design Decisions	Aggregate Identification, Invariant Classification, Functorium Pattern Mapping
2. Code	Domain Code Design	VO, Smart Enum, Aggregate, Domain Service Code
3. Results	Domain Implementation Results	Type Count Summary, Folder Structure, Test Status

Application Track

Step	Document	Description
0. Requirements	Application Business Requirements	Workflow Rules, Event-Reactive Flows
1. Design	Application Type Design Decisions	Command/Query/Port Identification, ApplyT, FinT Composition
2. Code	Application Code Design	Command Handler, Event Handler Code
3. Results	Application Implementation Results	UseCase/Port Summary, Applied Pattern Overview

Adapter Track

Step	Document	Description
0. Requirements	Adapter Technical Requirements	Persistence, External Services, HTTP API, Observability Requirements
1. Design	Adapter Type Design Decisions	IO Pattern Selection Rationale, Observable Port Design
2. Code	Adapter Code Design	Advanced IO Patterns, DI Registration Code
3. Results	Adapter Implementation Results	Endpoints, Implementations, Test Status

Observability Track

Step	Document	Description
0. Requirements	Observability Business Requirements	3-Pillar Requirements, SLO Targets
1. Design	Observability Type Design Decisions	KPI-Metric Mapping, ctx.* Propagation Strategy
2. Code	Observability Code Design	L1/L2 Dashboards, Alert Rules, PromQL
3. Results	Observability Implementation Results	Observable Port, Pipeline, IO Pattern Status

Project Structure

samples/ai-model-governance/
├── AiModelGovernance.slnx                        # Solution file (8 projects)
├── 00-project-spec.md                            # Project requirements specification
├── 01-architecture-design.md                     # Architecture design
├── domain/                                       # Domain layer docs (4)
├── application/                                  # Application layer docs (4)
├── adapter/                                      # Adapter layer docs (4)
├── observability/                                # Observability docs (4)
├── Src/
│   ├── AiGovernance.Domain/
│   │   ├── SharedModels/Services/                # Domain Services
│   │   └── AggregateRoots/
│   │       ├── Models/                           # AIModel, VOs, Specs
│   │       ├── Deployments/                      # ModelDeployment, VOs, Specs
│   │       ├── Assessments/                      # ComplianceAssessment, AssessmentCriterion, VOs, Specs
│   │       └── Incidents/                        # ModelIncident, VOs, Specs
│   ├── AiGovernance.Application/
│   │   └── Usecases/
│   │       ├── Models/                           # Commands, Queries, Ports
│   │       ├── Deployments/                      # Commands, Queries, Ports
│   │       ├── Assessments/                      # Commands, Queries, EventHandlers
│   │       └── Incidents/                        # Commands, Queries, EventHandlers
│   ├── AiGovernance.Adapters.Persistence/
│   │   ├── Models/                               # Repository, Query (InMemory + EfCore)
│   │   ├── Deployments/
│   │   ├── Assessments/
│   │   ├── Incidents/
│   │   └── Registrations/                        # DI Registration
│   ├── AiGovernance.Adapters.Infrastructure/
│   │   ├── ExternalServices/                     # Advanced IO Feature Demos (4 types)
│   │   └── Registrations/                        # DI Registration
│   ├── AiGovernance.Adapters.Presentation/
│   │   ├── Endpoints/                            # FastEndpoints (15 types)
│   │   └── Registrations/                        # DI Registration
│   └── AiGovernance/                             # Host (Program.cs)
└── Tests/
    ├── AiGovernance.Tests.Unit/                  # Unit Tests
    └── AiGovernance.Tests.Integration/           # Integration Tests

How to Run

# Build
dotnet build Docs.Site/src/content/docs/samples/ai-model-governance/AiModelGovernance.slnx

# Test (268 tests)
dotnet test --solution Docs.Site/src/content/docs/samples/ai-model-governance/AiModelGovernance.slnx

Aggregate Relationship Diagram

Summary Statistics

Item	Count
Aggregate Root	4
Value Object	16 (String 6, Comparable 2, Smart Enum 8)
Domain Service	2
Specification	12
Domain Event	18
Command	8
Query	7
Event Handler	2
HTTP Endpoint	15
Observable Port	19
Advanced IO Pattern	4 (Timeout, Retry, Fork, Bracket)
Total Tests	268