Custom Attributes (attr)

While Scapius provides a comprehensive set of built-in properties, enterprise architecture teams frequently need to record bespoke metadata, FinOps cost codes, compliance identifiers, and cloud provider tags.

The attr keyword allows defining namespaced key-value pairs on any entity or relationship.

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Syntax

attr (<namespace>:)*<attribute_name> <value>

• Namespace (optional): snake_case prefix indicating the domain (e.g. aws, finops, sec, k8s).
• Attribute Name: snake_case identifier.
• Value: String ("value"), Boolean (true / false), or Numeric literal (123, 99.9).

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Usage on Entities

system sys_order_router "Order Router" {
    # Custom cloud metadata
    attr aws:account_id "123456789012"
    attr aws:region "us-east-1"

    # FinOps metadata
    attr finops:cost_center "CC-9012"
    attr finops:chargeback_enabled true

    # Custom security categorization
    attr sec:cmdb_id "CMDB-SYS-4410"
    attr sec:critical_infrastructure true
}

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Usage on Relationships

Custom attributes can also be attached to relationship property blocks:

sys_order_router flows_to sys_warehouse "Transfers packing slips" {
    attr net:protocol "mTLS"
    attr net:port 8443
    attr kafka:topic "orders.fulfillment.v1"
}

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Best Practices for Namespaces

Namespace Prefix	Recommended Usage	Example
cloud: / aws: / azure:	Cloud provider runtime metadata	attr cloud:vpc "vpc-0a81"
finops:	Cost centers, chargeback allocations	attr finops:cost_center "CORP-IT"
sec:	Security classifications & CMDB tags	attr sec:data_steward "Jane Doe"
arch:	Architecture review board tracking	attr arch:arb_approval_date "2026-04-01"

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Querying Custom Attributes in Views & Styles

Custom attributes are first-class query targets in view where clauses and style rule predicates using the attr.<namespace:attribute_name> syntax:

views {
    landscape cloud_landscape "US-East AWS Landscape" {
        # Filter entities matching custom attribute queries
        include system where attr.aws:region == "us-east-1"
        exclude system where attr.finops:chargeback_enabled == false

        # Apply predicate-based conditional styling to custom attributes
        style system where attr.sec:critical_infrastructure == true {
            css_class "critical-border"
        }
    }
}

The predicate evaluator automatically infers and resolves attribute types (string, boolean, or numeric) and supports equality (==, !=), string matching (contains, starts_with, ends_with), and comparison operators (>, <, >=, <=).