This template provides a simple chain template showcasing the usage of LLM Caching backed by Apache Cassandra® or Astra DB through CQL.
To set up your environment, you will need the following:
- an Astra Vector Database (free tier is fine!). You need a Database Administrator token, in particular the string starting with
- likewise, get your Database ID ready, you will have to enter it below;
- an OpenAI API Key. (More info here, note that out-of-the-box this demo supports OpenAI unless you tinker with the code.)
Note: you can alternatively use a regular Cassandra cluster: to do so, make sure you provide the
USE_CASSANDRA_CLUSTER entry as shown in
.env.template and the subsequent environment variables to specify how to connect to it.
To use this package, you should first have the LangChain CLI installed:
pip install -U langchain-cli
To create a new LangChain project and install this as the only package, you can do:
langchain app new my-app --package cassandra-synonym-caching
If you want to add this to an existing project, you can just run:
langchain app add cassandra-synonym-caching
And add the following code to your
from cassandra_synonym_caching import chain as cassandra_synonym_caching_chain
add_routes(app, cassandra_synonym_caching_chain, path="/cassandra-synonym-caching")
(Optional) Let's now configure LangSmith. LangSmith will help us trace, monitor and debug LangChain applications. LangSmith is currently in private beta, you can sign up here. If you don't have access, you can skip this section
export LANGCHAIN_PROJECT=<your-project> # if not specified, defaults to "default"
If you are inside this directory, then you can spin up a LangServe instance directly by:
This will start the FastAPI app with a server is running locally at http://localhost:8000
We can see all templates at http://127.0.0.1:8000/docs We can access the playground at http://127.0.0.1:8000/cassandra-synonym-caching/playground
We can access the template from code with:
from langserve.client import RemoteRunnable
runnable = RemoteRunnable("http://localhost:8000/cassandra-synonym-caching")
Stand-alone LangServe template repo: here.