Transforms

Validation modes: Validation modes reference

Transform attaches decode/encode functions to schemas without mutating them (stored in a WeakMap). After a transform is registered, instantiate() automatically applies the decoder before validation — decode's output is what gets validated, defaulted, and stripped. See Canonical decode/default ordering.

Methods

Method	Description	Mode
Transform.create / jt.encode	Attach decode/encode pair; encode domain → wire	Compile-time + Runtime
Transform.brand	Compile-time nominal brand (no runtime effect)	Compile-time
Transform.chain	Multi-step decode/encode chain	Compile-time + Runtime

All examples use the bookstore domain.

Related

• instantiate - applies decode during instantiation
• dump - applies encode during serialization
• jt.encode - single-schema encode step
• Constraint brands - automatic brands from JSON Schema keywords

See also

• Bookstore domain - schemas used throughout transform examples
• Picking a method - when transforms are applied vs when to apply manually