What problem does it solve?
LangChain streamlines building reliable LLM applications by giving you reusable building blocks for prompts, tools, RAG, and agents, while reducing token cost and output brittleness.
Core Features & Use Cases
- LCEL/Runnable composition: create end-to-end pipelines by wiring prompt | model | parser into traceable, batchable Runnables.
- Typed structured outputs: generate validated Pydantic results via with_structured_output, avoiding fragile json parsing.
- Tool calling & agents: expose Python tools to the model and run v1 agents via create_agent (LangGraph-backed).
- RAG-ready retrieval: connect retrievers and vector stores into chains for grounded answers with optional compression/reranking.
- Streaming & observability: stream tokens or semantic events and enable LangSmith tracing with run_name, tags, and metadata.
Quick Start
Use the langchain skill to build a LangChain v1 RAG chain for your question with typed structured output from the model.