json-serialization

Generate JSON serialization in Flutter by annotating model classes with @JsonSerializable and running build_runner to create *.g.dart files. This automates mapping API responses and persisted state to Dart objects.

The best way to keep Dart models in sync with API schemas is using json_serializable for code generation. It automatically updates serialization logic when you change model annotations, preventing manual mapping errors.

Yes, json_serializable supports immutability for Dart data models. You can apply annotations to immutable classes to generate standard fromJson and toJson methods without writing boilerplate code.

You need build_runner for Dart JSON serialization to execute the code generator that produces *.g.dart files. It compiles your @JsonSerializable annotations into functional mapping code during development.

Use code generation instead of manual JSON parsing in Flutter when managing multiple model classes, API responses, or persisted state. It standardizes data models, reduces boilerplate, and prevents serialization errors across your project.