# RAG - AstraDB This template will perform RAG using `AstraDB` (`AstraDB` vector store class) ## Environment Setup An [Astra DB](https://astra.datastax.com) database is required; free tier is fine. - You need the database **API endpoint** (such as `https://0123...-us-east1.apps.astra.datastax.com`) ... - ... and a **token** (`AstraCS:...`). Also, an **OpenAI API Key** is required. _Note that out-of-the-box this demo supports OpenAI only, unless you tinker with the code._ Provide the connection parameters and secrets through environment variables. Please refer to `.env.template` for the variable names. ## Usage To use this package, you should first have the LangChain CLI installed: ```shell pip install -U "langchain-cli[serve]" ``` To create a new LangChain project and install this as the only package, you can do: ```shell langchain app new my-app --package rag-astradb ``` If you want to add this to an existing project, you can just run: ```shell langchain app add rag-astradb ``` And add the following code to your `server.py` file: ```python from astradb_entomology_rag import chain as astradb_entomology_rag_chain add_routes(app, astradb_entomology_rag_chain, path="/rag-astradb") ``` (Optional) Let's now configure LangSmith. LangSmith will help us trace, monitor and debug LangChain applications. You can sign up for LangSmith [here](https://smith.langchain.com/). If you don't have access, you can skip this section ```shell export LANGCHAIN_TRACING_V2=true export LANGCHAIN_API_KEY= export LANGCHAIN_PROJECT= # if not specified, defaults to "default" ``` If you are inside this directory, then you can spin up a LangServe instance directly by: ```shell langchain serve ``` This will start the FastAPI app with a server is running locally at [http://localhost:8000](http://localhost:8000) We can see all templates at [http://127.0.0.1:8000/docs](http://127.0.0.1:8000/docs) We can access the playground at [http://127.0.0.1:8000/rag-astradb/playground](http://127.0.0.1:8000/rag-astradb/playground) We can access the template from code with: ```python from langserve.client import RemoteRunnable runnable = RemoteRunnable("http://localhost:8000/rag-astradb") ``` ## Reference Stand-alone repo with LangServe chain: [here](https://github.com/hemidactylus/langserve_astradb_entomology_rag).