---
type: object
properties:
  agreement_period_id:
    type: integer
    description: internally assigned identifier
    readOnly: true
  agreement_id:
    type: integer
    description: Internal agreement identifier
  started_on:
    type: string
    format: date
    description: Start of the agreement period
  ended_on:
    type:
      - string
      - "null"
    format: date
    description: End of the agreemnent period
  cancellation_deadline:
    type:
      - string
      - "null"
    format: date
    description: Deadline for the cancellation
  notes:
    type:
      - string
      - "null"
additionalProperties: false
required:
  - started_on