langchain4j-ai-services-patterns

Type-safe AI services in Java using interface-based patterns, annotations, and declarative configuration. This skill provides guidance for building declarative AI Services with LangChain4j using interface-based patterns, annotations for system and user messages, memory management, tools integration, and advanced AI application patterns that abstract away low-level LLM interactions. LangChain4j AI Services define AI functionality using Java interfaces with annotations, providing type-safe, declarative AI with minimal boilerplate. Use this skill when: Follow these steps to create declarative AI Services with LangChain4j: Create a Java interface with method signatures for AI interactions: Use @SystemMessage and @UserMessage annotations to define prompts: Use AiServices builder or create to instantiate the service: Add memory management using @MemoryId for multi-user scenarios: Register tools using @Tool annotation to enable AI function execution: Test AI services with concrete validation patterns: See examples.md for comprehensive practical examples including: Complete API documentation, annotations, interfaces, and configuration patterns are available in references.md . - Define AI capabilities as plain Java interfaces with @SystemMessage and @UserMessage annotations, eliminating manual prompt construction and response parsing - Built-in memory management for multi-turn...