Task management,
structured.

# Task Management System — Schema

## Entities

### Users
| Field | Type | Required | Description |
| :--- | :--- | :---: | :--- |
| `id` | string · uuid | Yes | Unique identifier for the user. |
| `name` | string | Yes | Display name of the user. |
| `email` | string · email | Yes | Email address of the user. |

### Tasks
| Field | Type | Required | Description |
| :--- | :--- | :---: | :--- |
| `id` | string · uuid | Yes | Unique identifier for the task. |
| `title` | string | Yes | Short, descriptive name of the task. |
| `description` | string | Yes | Details of the work to be completed. |
| `status` | string · enum | Yes | One of: todo, in_progress, done. |
| `assigned_to_user_id` | string · uuid | Yes | References the id of the assigned user. |

## Relationship

| From | To | Cardinality | Key mapping | Rule |
| :--- | :--- | :--- | :--- | :--- |
| Users | Tasks | One-to-many (1:N) | `tasks.assigned_to_user_id` → `users.id` | Each task is assigned to exactly one user; a user can have zero or many tasks. |

> JSON Schema validates document structure. Uniqueness of IDs and whether an assigned user exists must be enforced by the application or database.

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "Task Management System",
  "description": "A collection of users and the tasks assigned to them.",
  "type": "object",
  "required": [
    "users",
    "tasks"
  ],
  "properties": {
    "users": {
      "type": "array",
      "description": "Users who can be assigned tasks.",
      "items": {
        "$ref": "#/$defs/User"
      }
    },
    "tasks": {
      "type": "array",
      "description": "Tasks assigned to users.",
      "items": {
        "$ref": "#/$defs/Task"
      }
    }
  },
  "additionalProperties": false,
  "$defs": {
    "User": {
      "type": "object",
      "required": [
        "id",
        "name",
        "email"
      ],
      "properties": {
        "id": {
          "type": "string",
          "format": "uuid",
          "description": "Unique identifier for the user."
        },
        "name": {
          "type": "string",
          "minLength": 1,
          "description": "Display name of the user."
        },
        "email": {
          "type": "string",
          "format": "email",
          "description": "Email address of the user."
        }
      },
      "additionalProperties": false
    },
    "Task": {
      "type": "object",
      "required": [
        "id",
        "title",
        "description",
        "status",
        "assigned_to_user_id"
      ],
      "properties": {
        "id": {
          "type": "string",
          "format": "uuid",
          "description": "Unique identifier for the task."
        },
        "title": {
          "type": "string",
          "minLength": 1,
          "description": "Short, descriptive name of the task."
        },
        "description": {
          "type": "string",
          "description": "Details of the work to be completed."
        },
        "status": {
          "type": "string",
          "enum": [
            "todo",
            "in_progress",
            "done"
          ],
          "description": "Current stage of the task."
        },
        "assigned_to_user_id": {
          "type": "string",
          "format": "uuid",
          "description": "References users[].id. Referential integrity is enforced by the application or database."
        }
      },
      "additionalProperties": false
    }
  }
}