Moshi is a modern JSON library for Kotlin and Java that handles parsing and serialization of JSON data into and from application objects.
Moshi solves the problem of converting between JSON and strongly-typed Java or Kotlin classes. It provides built-in type adapters for core data types including primitives, collections, strings, and enums, automatically handling field-by-field serialization and deserialization of model classes. For cases where the default behavior does not fit, developers can write custom type adapters using methods annotated with @ToJson and @FromJson, allowing fine-grained control over how values are encoded and decoded. Type adapters can work with intermediate representations, enabling transformations such as combining multiple JSON fields into a single object property or reformatting field names during parsing.
Moshi suits projects that need straightforward JSON handling without heavy configuration. It works well for Android applications and backend services written in Java or Kotlin. The library is particularly valuable when you need to customize serialization behavior for specific types without writing boilerplate parsing code. Developers should be aware that Kotlin support requires either code generation or the KotlinJsonAdapterFactory for reflection, as plain Java-based reflection does not work with Kotlin classes.
The project maintains active development with regular updates to its codebase. Pull requests receive timely review and feedback from maintainers. The issue tracker shows consistent engagement with bug reports and feature requests, with maintainers providing detailed responses and guidance. Documentation is kept current alongside code changes, and the project demonstrates responsiveness to community contributions.
