CQRS

Command Query Responsibility Segregation uses different models for changing state and reading state. Apply it where read and write behavior genuinely diverge; simple CRUD systems rarely need the extra coordination.

src/app/
├── commands/
├── queries/
├── domain/
├── write_infrastructure/
├── read_infrastructure/
└── interface/

Complete Configuration

deply:
  paths: ["."]
  exclude_files:
    - '.*/\.venv/.*'
    - '.*/tests?/.*'
  layers:
    - name: commands
      collectors:
        - type: directory
          directories: ["src/app/commands"]
    - name: queries
      collectors:
        - type: directory
          directories: ["src/app/queries"]
    - name: domain
      collectors:
        - type: directory
          directories: ["src/app/domain"]
    - name: write_infrastructure
      collectors:
        - type: directory
          directories: ["src/app/write_infrastructure"]
    - name: read_infrastructure
      collectors:
        - type: directory
          directories: ["src/app/read_infrastructure"]
    - name: interface
      collectors:
        - type: directory
          directories: ["src/app/interface"]
  ruleset:
    domain:
      disallow_layer_dependencies: [commands, queries, write_infrastructure, read_infrastructure, interface]
    commands:
      disallow_layer_dependencies: [queries, write_infrastructure, read_infrastructure, interface]
    queries:
      disallow_layer_dependencies: [commands, domain, write_infrastructure, interface]
    write_infrastructure:
      disallow_layer_dependencies: [queries, read_infrastructure, interface]
    read_infrastructure:
      disallow_layer_dependencies: [commands, domain, write_infrastructure, interface]

This example lets queries use read infrastructure while command handlers own ports implemented by write infrastructure. Deply cannot verify synchronization, eventual consistency, idempotency, or command semantics.

Validate

deply validate --config=deply.yaml
deply analyze --parallel --config=deply.yaml

References: CQRS and the CQRS pattern guidance.