AppBuilder-SDK is a client SDK that enables AI-native application developers to build, orchestrate, monitor, and deploy AI-powered apps on Baidu AppBuilder. It supports core capabilities across invocation, orchestration, monitoring, and deployment. Developers can call large language models and integrate 40+ Baidu ecosystem components to empower Agent applications, as well as access and manage AI-native applications published in the AppBuilder console and register local functions to link cloud components. For knowledge-driven use cases, KnowledgeBase management enables document parsing, chunking, embedding, indexing, and retrieval to support industrial-grade RAG workflows. The SDK provides multi-level workflow abstractions (Message, Component, AgentRuntime) to orchestrate complex pipelines and can connect with LangChain and OpenAI ecosystem capabilities. Production observability is enhanced with visual tracing and detailed debug logs. Deployment options include deploying AgentRuntime as a Flask/gunicorn API service, as a Chainlit frontend, and using the appbuilder_bce_deploy tool to publish public APIs on Baidu Cloud. The documentation also offers end-to-end cookbooks and examples illustrating how to assemble robust RAG apps.