Production-ready AI agent framework for Java. Built on Spring Boot 4 and LangChain4j, Gargantua turns Java methods (@AgentTool) and Markdown files (SKILL.md) into a deployable agent service with skills, hybrid routing, 3-layer memory, guardrails, human-in-the-loop approvals, multi-provider LLM failover, RAG with a pluggable EmbeddingPort, A2A protocol, MCP server gateway, cost tracking and an immutable audit trail. Ships an embedded zero-infra mode for tests and demos.