Gen-AI Developer Classroom notes 12/Jul/2025

Langchain & LangGraph

• Langchain:
  • Langchain abstracts the llm interactions
    
  • Langchain provides all the necessary tooling to build the ai enable applications
    
    
• Langgraph:
  • Langgraph helps in building complex agent by creating workflows as graphs Refer Here

Abstraction

• To interact with models (llm) langchain has chat models
• setup:
  • create a new folder
  • execute uv init
  • create virtual environment
  • add langchain package uv add langchain
• Get API Keys of any model. Generally we need to set them as environmental variables.
  • openai
• Add langchain[openai] package for openai interactions
• Add langchain[google-vertexai] package for model interaction based on gcp account.
• Refer Here the notes for basic interaction.

Setting up GCP ACCOUNT for accessing from langchain/langgraph

• Ensure GCP account is active
• install gcloud cli windows, mac
• login into gcloud from cli gcloud init
• and execute gcloud auth application-default login