Auto is a collection of source code generators for Java that automate the creation of boilerplate code through annotation processing.
Java projects often require mechanical, repetitive code that is tedious to write, error-prone, and rarely tested. Auto solves this by providing annotation processors that generate the code you would write manually, eliminating bugs and saving development time. The tool works by processing annotations at compile time and generating source code automatically, so developers declare their intent through annotations and let the generators handle implementation details.
Auto consists of several focused subprojects. AutoValue generates immutable value-type classes with automatically implemented equals, hashCode, and toString methods for Java 8 and later. AutoFactory creates JSR-330-compatible factory classes for dependency injection. AutoService generates provider-configuration files needed by Java's ServiceLoader mechanism. The project also includes Common, a set of helper utilities for developers writing their own annotation processors. Teams should adopt Auto when they want to reduce boilerplate in value objects, factories, or service provider declarations. It is particularly valuable for libraries and frameworks that need clean, maintainable code without manual implementation of standard patterns.
The project maintains a steady stream of commits addressing bug fixes and minor improvements, with pull requests reviewed and merged regularly. Development activity shows consistent engagement with issues and maintenance of the codebase. The project accepts external contributions and processes them through standard review workflows. Updates are released periodically to address compatibility with newer Java versions and fix reported problems.
