Type System¶

The OpenMetadata type system provides reusable type definitions used across all schemas.

Overview¶

Types are fundamental building blocks that are referenced by entity schemas. They ensure consistency and enable schema composition.

Type Categories¶

Basic Types¶

Core primitive types: - UUID, Email, Timestamp, Duration - URI, Markdown, Expression - Entity links and references

Collection Types¶

Composite types: - Arrays and lists - Entity references - Tag labels - Change descriptions

Custom Properties¶

Extension mechanism: - User-defined properties - Type-safe extensions - Schema-less flexibility

Usage¶

Types are referenced using JSON Schema $ref:

{
  "owner": {
    "$ref": "../../type/entityReference.json"
  }
}

This enables: - Reusability: Define once, use everywhere - Consistency: Same type across all entities - Validation: Centralized validation rules - Documentation: Single source of truth