# Extraction - OpenAI functions This template uses [OpenAI function calling](https://python.langchain.com/docs/modules/chains/how_to/openai_functions) for extraction of structured output from unstructured input text. The extraction output schema can be set in `chain.py`. ## Environment Setup Set the `OPENAI_API_KEY` environment variable to access the OpenAI models. ## Usage To use this package, you should first have the LangChain CLI installed: ```shell pip install -U langchain-cli ``` To create a new LangChain project and install this as the only package, you can do: ```shell langchain app new my-app --package extraction-openai-functions ``` If you want to add this to an existing project, you can just run: ```shell langchain app add extraction-openai-functions ``` And add the following code to your `server.py` file: ```python from extraction_openai_functions import chain as extraction_openai_functions_chain add_routes(app, extraction_openai_functions_chain, path="/extraction-openai-functions") ``` (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/extraction-openai-functions/playground](http://127.0.0.1:8000/extraction-openai-functions/playground) We can access the template from code with: ```python from langserve.client import RemoteRunnable runnable = RemoteRunnable("http://localhost:8000/extraction-openai-functions") ``` By default, this package is set to extract the title and author of papers, as specified in the `chain.py` file. LLM is leveraged by the OpenAI function by default.