Provides patterns to generate comprehensive REST API documentation using SpringDoc OpenAPI 3.0 and Swagger UI in Spring Boot 3.x applications. Use when setting up API documentation, configuring Swagger UI, adding OpenAPI annotations, implementing security documentation, or enhancing REST endpoints with examples and schemas.

Provides patterns for testing Spring application events (ApplicationEvent) with @EventListener and ApplicationEventPublisher. Handles event publishing, listening, and async event handling in Spring Boot applications. Use when validating event-driven workflows in your Spring Boot services.

Provides JWT authentication and authorization patterns for Spring Boot 3.5.x covering token generation with JJWT, Bearer/cookie authentication, database/OAuth2 integration, and RBAC/permission-based access control using Spring Security 6.x. Use when implementing authentication or authorization in Spring Boot applications.

Provides patterns to build declarative AI Services with LangChain4j using interface-based patterns, annotations, memory management, tools integration, and advanced application patterns. Use when implementing type-safe AI-powered features with minimal boilerplate code in Java applications.

Edge case and boundary testing patterns for unit tests. Testing minimum/maximum values, null cases, empty collections, and numeric precision. Pure JUnit 5 unit tests. Use when ensuring code handles limits and special cases correctly.

Provides dependency injection patterns for Spring Boot projects covering constructor-first patterns, optional collaborator handling, bean selection, and validation practices. Use when configuring beans, wiring dependencies, or troubleshooting injection issues.

Provides REST API design standards and best practices for Spring Boot projects. Use when creating or reviewing REST endpoints, DTOs, error handling, pagination, security headers, HATEOAS and architecture patterns.

Provides patterns to configure Spring Boot Actuator for production-grade monitoring, health probes, secured management endpoints, and Micrometer metrics across JVM services. Use when setting up monitoring, health checks, or metrics for Spring Boot applications.

Provides Amazon DynamoDB patterns using AWS SDK for Java 2.x. Use when creating, querying, scanning, or performing CRUD operations on DynamoDB tables, working with indexes, batch operations, transactions, or integrating with Spring Boot applications.

This skill should be used when implementing fault tolerance and resilience patterns in Spring Boot applications using the Resilience4j library. Apply this skill to add circuit breaker, retry, rate limiter, bulkhead, time limiter, and fallback mechanisms to prevent cascading failures, handle transient errors, and manage external service dependencies gracefully in microservices architectures.

Provides patterns for unit testing utility/helper classes and static methods. Validates pure functions and helper logic. Use when verifying utility code correctness.

Provides parameterized testing patterns with @ParameterizedTest, @ValueSource, @CsvSource. Enables running a single test method with multiple input combinations. Use when testing multiple scenarios with similar logic.

Provides patterns for unit testing REST controllers using MockMvc and @WebMvcTest. Validates request/response mapping, validation, and exception handling. Use when testing web layer endpoints in isolation.

Provides patterns for unit testing JSON serialization/deserialization with Jackson and @JsonTest. Use when validating JSON mapping, custom serializers, and date format handling.

Provides patterns for unit testing service layer with Mockito. Validates business logic in isolation by mocking dependencies. Use when testing service behaviors and business logic without database or external services.

Provides AWS CloudFormation patterns for Amazon ElastiCache. Use when creating ElastiCache clusters (Redis, Memcached), replication groups, parameter groups, subnet groups, and implementing template structure with Parameters, Outputs, Mappings, Conditions, and cross-stack references for distributed caching infrastructure.

Validates a skill against DevKit standards (requirements, template, dependencies). Use when you need to verify a skill before publishing or after modifications.

Extract subtitles/transcripts from a YouTube video URL and save as a local file. Use when you need to extract subtitles from a YouTube video.

Generate, remix, or edit images with Nanobanana / Nano Banana 2 through the bundled Gemini CLI wrapper. Use this whenever the user wants AI image generation or editing, especially for reference-image composition, character consistency, grounded visuals that may need live web search, style transfer, marketing graphics, product mockups, social assets, or when they explicitly mention Nanobanana, Gemini image models, Google image generation, AI drawing, 图片生成, AI绘图, 图片编辑, or 生成图片.

Use when work must continue across multiple Codex sessions with `.autonomous/` tracking, resumable execution, or autonomous handoff. Use for long-running, multi-session, or resume-later tasks.