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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 - it shows off the various Expression Language pieces in order from simple to more complex.


The base interface shared by all LCEL objects


Examples of common LCEL usage patterns

Why use LCEL

A deeper dive into the benefits of LCEL

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