LangChain Expression Language

LCEL Coding Cheatsheet

Same pipe (|), same invoke / stream / batch. Swap ChatOpenAI and ChatAnthropic without rewriting the graph.

Snippet view 


          
          

            
            

          

        

      

    


    

      
Same prompt, two constructors. Copy either side into a notebook.

      
      
      

        

          
          
        

        

          
          
        

      

      
      

        

          
          

        

        

          
          

        

      

    


    

      

        
PrimitiveMeaning

        
      

      

        
Install

        
pip install langchain-core langchain-openai langchain-anthropic langchain
export OPENAI_API_KEY=...
export ANTHROPIC_API_KEY=...