Skip to main content

Tool use

An exciting use case for LLMs is building natural language interfaces for other β€œtools”, whether those are APIs, functions, databases, etc. LangChain is great for building such interfaces because it has:

  • Good model output parsing, which makes it easy to extract JSON, XML, OpenAI function-calls, etc. from model outputs.
  • A large collection of built-in Tools.
  • Provides a lot of flexibility in how you call these tools.

There are two main ways to use tools: chains and agents.

Chains lets you create a pre-defined sequence of tool usage(s).


Agents let the model use tools in a loop, so that it can decide how many times to use tools.


To get started with both approaches, head to the Quickstart page.