Structurizr Architecture Synchronization

Context (Input)

Use this skill when:

• Adding new components (controllers, handlers, services, repositories)
• Creating new entities or aggregates
• Modifying component relationships or dependencies
• Implementing new architectural patterns (CQRS, events, subscribers)
• Adding infrastructure components (databases, caches, message brokers)
• Refactoring that changes component structure
• After fixing Deptrac violations (may indicate architecture drift)
• Creating new bounded contexts or modules
• Implementing new API endpoints with significant handlers

Task (Function)

Keep the Structurizr workspace (workspace.dsl) synchronized with codebase changes, ensuring C4 model diagrams accurately represent the current system architecture.

Success Criteria:

• workspace.dsl contains all significant components
• Component relationships match actual code dependencies
• Layer groupings (Application/Domain/Infrastructure) are accurate
• Component descriptions reflect current purpose
• All infrastructure dependencies are documented
• C4 diagrams render without errors (check at http://localhost:${STRUCTURIZR_PORT:-8080})

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Quick Start: Update Architecture in 5 Steps

Complete Template: See reference/workspace-template.md for full workspace.dsl structure.

Step 1: Identify Architectural Changes

Determine if your code changes are architecturally significant:

✅ DO update workspace.dsl when adding:

• Processors (HTTP/GraphQL handlers)
• Command Handlers (CQRS pattern)
• Event Subscribers (event-driven patterns)
• Entities (core domain objects)
• Domain Events (significant business events)
• Repositories (data access)
• Event Bus or infrastructure services
• External dependencies (DB, Cache, Message Broker)

❌ DON'T update for:

• Factory classes
• Transformer classes (unless critical)
• Value objects (unless architecturally significant)
• Interface definitions (except hexagonal ports)
• Base classes
• DTOs and input/output objects
• Utility classes and helpers

Target: 15-25 components per diagram for clarity.

Step 2: Add Component to Appropriate Group

Edit workspace.dsl and add component in the correct layer group:

group "Application" {
    newProcessor = component "NewProcessor" "Handles new requests" "RequestProcessor" {
        tags "Item"
    }
}

Layers:

• group "Application" - Controllers, Processors, Handlers, Subscribers
• group "Domain" - Entities, Domain Events
• group "Infrastructure" - Repositories, Event Bus, Infrastructure services

External dependencies (database, cache, messageBroker) go OUTSIDE groups at container level.

See: reference/dsl-syntax.md for complete syntax.

Step 3: Define Relationships

Add relationships showing how your component interacts:

// After all component definitions
newProcessor -> commandHandler "dispatches NewCommand"
commandHandler -> repository "uses"
repository -> database "accesses data"

Common patterns: See reference/relationship-patterns.md

Step 4: Verify Diagram Renders

View the updated diagram:

# Refresh browser (Structurizr Lite auto-reloads)
# Port is configurable via STRUCTURIZR_PORT in .env (default: 8080)
open http://localhost:${STRUCTURIZR_PORT:-8080}
# Navigate to "Diagrams" → "Components_All"

Check for:

• No syntax errors displayed
• New component appears
• Relationships are visible
• Component is in correct layer group

Step 5: Position and Commit

1. Drag components in the UI to improve layout
2. Click "Save workspace" button (saves to workspace.json)
3. Commit both files:

git add workspace.dsl workspace.json
git commit -m "feat: update architecture with new processor"

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Diagram as Code Workflow

Setup (Already Configured)

Docker: Structurizr Lite runs in docker-compose.override.yml:

structurizr:
  image: structurizr/lite:2024.07.02
  ports:
    - '${STRUCTURIZR_PORT}:8080'
  volumes:
    - ./:/usr/local/structurizr

Access: http://localhost:${STRUCTURIZR_PORT:-8080} (port configurable via .env)

Standard Development Flow

1. Implement code changes → Add handler, entity, repository
2. Update workspace.dsl → Add component + relationships
3. View locally → Refresh browser at configured port
4. Position components → Drag in UI, click "Save workspace"
5. Commit together → Code + workspace.dsl + workspace.json in same PR

Manual Positioning in UI

Automatic layout doesn't work well - use manual positioning:

1. Open Structurizr UI in browser
2. Navigate to "Diagrams" → "Components_All"
3. Drag components to arrange (left-to-right flow recommended)
4. Click "Save workspace" button in top-right
5. Positions saved to workspace.json in project root
6. Commit workspace.json with workspace.dsl

Layout best practices:

• Processors/Controllers on the left (entry points)
• Command Handlers in the middle (business logic)
• Repositories to the right of handlers
• Database/Cache/Message Broker on far right (external)

Common mistakes: See reference/common-mistakes.md for complete guide.

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Reference Documentation

Detailed Guides

• C4 Model Fundamentals - Understanding C4 modeling
• DSL Syntax Reference - Complete Structurizr DSL syntax
• Component Identification - What to document
• Relationship Patterns - Common relationship types
• Workspace Template - Complete workspace.dsl template
• Common Mistakes - Pitfalls and solutions

Examples

• Adding CQRS Pattern - Command handlers, events, subscribers
• Adding API Endpoint - Controllers, processors, transformers
• Adding Domain Entity - Entities, value objects, factories
• Refactoring Components - Updating relationships during refactoring

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Critical Principles

What Makes a Good Architecture Diagram

Clarity over Completeness:

• 15-25 components (optimal readability)
• Focus on architectural significance
• Clear left-to-right or top-to-bottom flow
• External dependencies clearly visible

Layer Separation:

• Application: Entry points and orchestration
• Domain: Business logic and entities
• Infrastructure: Technical implementation

Meaningful Relationships:

• Show actual code dependencies
• Use descriptive labels
• Avoid circular dependencies

Alignment with Deptrac

Layer groupings in workspace.dsl MUST match Deptrac configuration:

group "Application"     ↔  Application layer in deptrac.yaml
group "Domain"          ↔  Domain layer in deptrac.yaml
group "Infrastructure"  ↔  Infrastructure layer in deptrac.yaml

This ensures architecture documentation matches enforced boundaries.

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Integration with Other Skills

Use this skill after:

• implementing-ddd-architecture - After creating domain model
• api-platform-crud - After adding API endpoints
• deptrac-fixer - After fixing layer violations

Use this skill before:

• documentation-sync - Update docs with architecture
• ci-workflow - Validate all changes

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Troubleshooting

Common Issues

Issue: Structurizr UI shows "Element does not exist" error

Solution: Check component variable names in relationships match the component definitions exactly. See common-mistakes.md.

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Issue: Diagram shows components in wrong positions after pull

Solution: Ensure workspace.json is committed along with workspace.dsl. The JSON file stores manual positions.

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Issue: DSL syntax validation fails

Solution:

1. Check balanced braces {}
2. Verify all components are defined before relationships
3. Ensure no duplicate variable names
4. Compare with workspace-template.md

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Issue: Too many components (30+), diagram is cluttered

Solution: Follow component-identification.md - aim for 15-25 components. Omit DTOs, utilities, and factories.

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Issue: Can't determine if component should be documented

Solution: Use the decision matrix in component-identification.md or the TL;DR section.

External Resources

• Structurizr DSL Documentation: https://docs.structurizr.com/dsl
• C4 Model: https://c4model.com/
• Structurizr Lite: https://docs.structurizr.com/lite
• User Service Example (VilnaCRM organization reference): https://github.com/VilnaCRM-Org/user-service/wiki/Design-and-Architecture-Documentation