Archetypes

The archetypes feature provides a way to create user defined types that extend the basic element/relationship types and optionally add some defaults for descriptions, technology, tags, properties, and perspectives. The key benefits are as follows:

• Archetypes reduce duplication (define a type once, use it anywhere).
• Archetypes lead to more concise DSL definitions.
• Archetypes allow teams to build their own ubiquitous language on top of the C4 model.

Element archetypes

Element archetypes can be defined for:

• person
• softwareSystem
• container
• component
• deploymentNode
• infrastructureNode
• group
• element

For example, you could define archetypes named application and datastore that are essentially just aliases for container.

workspace {

    model {
        archetypes {
            application = container
            datastore = container
        }
        
        softwareSystem "A" {
            webapp = application "Web Application"
            db = datastore "Database Schema"
            
            webapp -> db "Reads from"
        }
    }
    
}

Element archetypes can have a set of defaults defined for:

• Description
• Technology (applies to containers and components only)
• Properties
• Perspectives
• Tags
• Metadata (applies to custom elements only)

workspace {

    model {
        archetypes {
            application = container {
                technology "Java"
                tag "Application"
            }
            datastore = container {
                technology "MySQL"
                tag "Data Store"
            }
        }
        
        softwareSystem "A" {
            webapp = application "Web Application"
            db = datastore "Database Schema"
            
            webapp -> db "Reads from"
        }
    }
    
}

Element archetypes can also be extended:

workspace {

    model {
        archetypes {
            application = container {
                technology "Java"
                tag "Application"
            }
            springBootApplication = application {
                technology "Spring Boot"
            }
            datastore = container {
                technology "MySQL"
                tag "Data Store"
            }
        }
        
        softwareSystem "A" {
            webapp = springBootApplication "Web Application"
            db = datastore "Database Schema"
            
            webapp -> db "Reads from"
        }
    }
    
}

Relationship archetypes

Relationship archetypes are also supported, with defaults defined for:

• Description
• Technology
• Properties
• Perspectives
• Tags

workspace {

    model {
        archetypes {
            sync = -> {
                tags "Synchronous"
            }
            https = --sync-> {
                technology "HTTPS"
            }
        }
        
        a = softwareSystem "A"
        b = softwareSystem "B"
        
        a --https-> b "Makes APIs calls using"
    }

}