Nucleus
Production-ready microservices foundation for Java/Spring Boot applications. Build business logic on day one.
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Authentication & Security

OAuth2/OIDC server with JWT rotating keys, role-based access control, and login audit trail. Drop-in security for any service.

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Declarative Audit Trail

One annotation on any method logs who did what, when. SpEL expressions for dynamic descriptions. Kafka-published for real-time dashboards.

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Email Pipeline

Kafka-driven email with Thymeleaf templates, SMTP delivery, step-by-step tracking, and resend capability. Full delivery audit trail.

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Messaging Abstraction

Pluggable Kafka publishers with transactional and fire-and-forget modes. JSON/XML/YAML serialization. Swap backends without code changes.

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Service Monitoring

Self-registration via heartbeats, remote log streaming toggled per-instance, remote shutdown, multi-instance identity. Zero-config observability.

Real-Time Push

Server-Sent Events with role-based delivery. Live dashboards, job progress, notifications — all through one SSE channel with message expiration.

Java 17 Spring Boot 3.5 Kafka / RabbitMQ JPA (Any DB) MinIO Angular 19 OAuth2/OIDC OpenAPI 3.0
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12 Production Modules

nucleus-coreBase components, JWT, pagination, reports
nucleus-authenticationOAuth2/OIDC with rotating keys
nucleus-audit-core@AuditAction declarative audit
nucleus-connectorsKafka messaging abstraction
nucleus-monitoring-clientSelf-registration, remote logging
nucleus-ui-message-brokerSSE with role-based delivery
nucleus-mailKafka email pipeline
nucleus-storageMinIO/S3 file storage
nucleus-execution-eventsAsync job framework
nucleus-configSpring Cloud Config Server
nucleus-userUser management & roles
nucleus-addressGoogle Maps address validation