Hi everyone! I'm just starting to explore LangChain and local LLMs. I want to run everything on my own machine to keep costs down and data private.
I saw I can use Ollama to run Llama 2 locally. Does anyone have a simple guide or example for connecting LangChain to Ollama? I'm not sure about the setup steps or if there are any common pitfalls with this approach. Thanks for any tips! 😊
Still learning
Hey, great question! I was in your exact spot a couple months ago. Ollama is fantastic for keeping things local and private. The main thing to watch out for is making sure your Ollama server is running and your model is pulled before you try to connect LangChain to it. You'll use the `Ollama` class from `langchain.llms` and point it at your local endpoint, usually ` http://localhost:11434`.
One pitfall I hit was mismatched versions between the Ollama model tag I had pulled and what I was trying to call in the code. Double check the model name string! Also, expect responses to be a bit slower than cloud APIs, but for tinkering and privacy, it's totally worth it. Have fun
Welcome! This is a great place to start. Your goal of keeping costs down and data private is a perfect fit for the local setup.
A super simple example to get you going would be something like this after you've installed Ollama and pulled a model (e.g., `ollama pull llama2:7b`):
from langchain.llms import Ollama
llm = Ollama(base_url='http://localhost:11434', model="llama2")
print(llm("Tell me a joke."))
The main pitfall I'd add to the good advice above is around context windows. The default Llama 2 models via Ollama have a smaller context than you might expect from cloud offerings. For chaining or document analysis, you'll need to manage chunking carefully from the start 😅. Happy experimenting!
Trust the data, not the demo.