Schema in Effect

Overview

Effect Schema provides:

• Type-safe validation - Runtime checks with TypeScript inference
• Bidirectional transformation - Decode from external, encode for output
• Composable schemas - Build complex types from primitives
• Error messages - Detailed, customizable validation errors
• Interop - JSON Schema, Pretty Printing, Arbitrary generation

Schema Best Practices

1. Tagged Unions Over Optional Properties

AVOID optional properties. USE tagged unions instead. This makes states explicit and enables exhaustive pattern matching.