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*   LangChain Expression Language

LangChain Expression Language (LCEL)
====================================

LangChain Expression Language or LCEL is a declarative way to easily compose chains together. Any chain constructed this way will automatically have full sync, async, and streaming support.

If you're looking for a good place to get started, check out the [Cookbook section](/v0.1/docs/expression_language/cookbook/) - it shows off the various Expression Language pieces in order from simple to more complex.

#### [Interface](/v0.1/docs/expression_language/interface/)[​](#interface "Direct link to interface")

The base interface shared by all LCEL objects

#### [Cookbook](/v0.1/docs/expression_language/cookbook/)[​](#cookbook "Direct link to cookbook")

Examples of common LCEL usage patterns

#### [Why use LCEL](/v0.1/docs/expression_language/why/)[​](#why-use-lcel "Direct link to why-use-lcel")

A deeper dive into the benefits of LCEL

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