Which LangChain Products, Languages, and Packages Are Covered in LangChain Reference Docs?

LangChain Reference Docs covers five product areas — LangChain, LangGraph, DeepAgents, LangSmith, and integrations — and spans Python, TypeScript, Java, and Go packages. It is the unified API reference for the LangChain ecosystem, meaning you can browse classes, functions, and types across all of these products and languages from one place. It is a reference site, not a tutorial site: if you need guides or conceptual explanations, the docs point you to the main documentation site instead.

Products covered

The reference documentation is organized around the following product areas:

If your work touches any of these five areas, the reference is the place to look up exact signatures, class members, and type definitions.

Languages and packages

The reference is browsable across four language ecosystems:

• Python packages
• TypeScript packages
• Java packages
• Go packages

This matters if your stack is not Python-first. You can check whether the class, function, or type you depend on exists in your language's package before committing to an integration approach.

What you can actually browse

Within each product and language, the reference exposes the API surface:

• Classes — constructors, methods, attributes
• Functions — parameters, return types
• Types — type definitions used across the ecosystem

The scope is described as covering the "entire LangChain ecosystem," so the reference is intended as a single entry point rather than one site per product.

How to decide whether this is the right resource

Use LangChain Reference Docs when you:

• Need the exact signature or type of an API you already know you want to use
• Are checking whether a feature exists in your language (Python, TypeScript, Java, or Go)
• Want to compare the API surface of two products, such as LangChain versus LangGraph

Look elsewhere when you:

• Are learning a concept for the first time and need a walkthrough
• Want a step-by-step tutorial or a conceptual overview — the reference explicitly directs you to the main documentation site for guides, tutorials, and conceptual docs

Practical check before you start

Because coverage is split across products and languages, confirm two things first: which product area your task belongs to (for example, LangGraph for graph workflows versus LangSmith for observability), and which language package you are working in. That combination determines which section of the reference is relevant to you. If a class or function you expect is not listed under your language, it may exist only in another language's package or only in a different product area — check both before assuming it is unavailable.