Introduction

Sprout is a compile-time annotation processor that generates Spring Boot REST scaffolding from your JPA entities. Annotate an entity, compile, and Sprout writes the REST layer into your build output. You ship less boilerplate; Spring picks it up automatically.

What Sprout generates

For every entity annotated with @SproutResource, Sprout produces five Java source files:

Generated type	What it is
Sprout{Name}Controller	@RestController exposing CRUD endpoints
Sprout{Name}Operations	Interface the controller depends on (your override point)
Sprout{Name}Service	Default implementation of the operations interface
Sprout{Name}Repository	JpaRepository subinterface with a custom JPQL deleteById
Sprout{Name}Marker	Class with public static final constants (path, ID type, entity name, policies)

Generated sources land in the entity’s package under a .generated subpackage, so Spring’s component scan picks them up automatically as long as your @SpringBootApplication covers the entity package.

The three modules

Sprout is published as three separate artifacts so you only pull in what you need:

sprout-annotations

Contains the public API:

• @SproutResource — marks an entity for generation and controls what is generated.
• @SproutPolicy — attaches SpEL-based security expressions per HTTP operation.
• @SproutId — overrides which field or getter Sprout treats as the entity identifier.
• Endpoint — enum used with include/exclude to select individual endpoints.

These annotations have RetentionPolicy.SOURCE; they exist only at compile time and are not present in the compiled bytecode.

Add this as a regular compile/implementation dependency.

sprout-processor

The javax.annotation.processing.Processor implementation. Registered automatically via Google AutoService so no META-INF/services wiring is needed on your end.

Configure this as an annotation processor in your build tool — not a normal dependency. See Installation for the exact Maven and Gradle snippets.

sprout-runtime (optional)

Provides Spring Boot auto-configuration for two optional features:

• Unified error responses — a @RestControllerAdvice that converts common exceptions (validation failures, 404s, internal errors) into a consistent JSON structure.
• Method-security auto-configuration — enables @EnableMethodSecurity via a property so @SproutPolicy policies are enforced without any manual setup.

Add this only if you want these runtime features; Sprout works without it.