LangChain Expression Language

LangChain Expression Language is a declarative way to easily compose chains together. Any chain constructed this way will automatically have full sync, async, and streaming support. See guides below for how to interact with chains constructed this way as well as cookbook examples.

📄️ Cookbook

In this notebook we'll take a look at a few common types of sequences to create.

📄️ Interface

In an effort to make it as easy as possible to create custom chains, we've implemented a "Runnable" protocol that most components implement. This is a standard interface with a few different methods, which makes it easy to define custom chains as well as making it possible to invoke them in a standard way. The standard interface exposed includes: