LangChain Quickstart

Simple and easy way to start learning LangChain

📖 Read the full tutorial: Run LangChain Locally in 15 Minutes Without a Single API Key

Pre requisites

Python 3.13.0

• Python 3.13.0

Installing pyenv is optional but recommended for managing Python versions.

pyenv install 3.13.0
pyenv local 3.13.0

Install Ollama

Follow the instructions at https://ollama.com/download/ to install Ollama on your system.

Download and serve a local model

ollama serve
ollama pull llama3.2

Create a virtual environment (optional but recommended)

python -m venv venv
source venv/bin/activate

Install Python dependencies

pip install langchain==1.0.3 langchain-ollama==1.0.0

or install directly from requirements.txt:

pip install -r requirements.txt

Run the example

python main.py

You should an output similar to:

Fog-get about it, it's always raining in San Francisco!