Arktype Patterns

Patterns for composing arktype schemas, naming runtime schema values alongside inferred types, and building discriminated unions with .merge() and .or().

When to Apply This Skill

• Defining a discriminated union schema (e.g., commands, events, actions)
• Composing a base type with per-variant fields
• Working with defineTable() schemas that use union types
• Importing or exporting schema values that share a name with inferred types

base.merge(type.or(...)) Pattern (Recommended)

Use when you have shared base fields and per-variant payloads discriminated on a literal key. .merge() distributes over unions: it merges the base into each branch of the union automatically.

import { type } from 'arktype';