Archetypes

The archetypes feature (from v4.0.0) 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

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"
        }
    }
    
}

Archetypes can have a set of defaults defined too:

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"
        }
    }
    
}

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:

workspace {

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

}