AI Developer (Level 7)
Topic Guide · 2026
LangChain
LangChain guide — the Python/JS framework for building LLM apps, RAG pipelines and AI agents in production.
Quick Answer
LangChain is the most popular open-source framework for building LLM-powered applications. It provides model integrations, prompt templates, memory, retrievers and agent primitives.
What you'll learn
- Chains, prompts, models, output parsers
- Retrievers and RAG
- Memory and tools
- LangSmith for tracing and evals
- LCEL (LangChain Expression Language)
- Deploy with LangServe
Recommended tools
LangChain PythonLangChain JSLangSmithLangServe
Frequently asked questions
LangChain vs LangGraph?+
LangChain — building blocks for LLM apps. LangGraph — stateful, graph-based orchestration for multi-agent systems. Use LangChain for RAG chatbots, LangGraph for agents.
Is LangChain still relevant in 2026?+
Yes. Every major AI startup and >70% of enterprise LLM stacks use LangChain, LangSmith or LangGraph for at least part of the pipeline.
Want LangChain training for your team?
Nirmal Rabari delivers this topic as a live corporate workshop across India, UAE, UK and US.