Authenticating External Services for LangChain in Python

An example Python app demonstrating how to integrate Pangea's Vault service into a LangChain app to authenticate with external services.

Prerequisites

• Python v3.12 or greater.
• pip v24.2 or uv v0.4.24.
• A Pangea account with Vault enabled.
• An OpenAI API key.
• A Google Drive folder containing documents. Note down the ID of the folder (see the LangChain docs for a guide on how to get the ID from the URL).
• A Google Cloud project with the Google Drive API enabled.
• A Google service account with the "https://www.googleapis.com/auth/drive.readonly" scope.

The Google service account's credentials will also need to be added to Vault. This would look like:

Save the ID of the new Vault item for later.

Setup

git clone https://github.com/pangeacyber/langchain-python-service-authn.git
cd langchain-python-service-authn

If using pip:

python -m venv .venv
source .venv/bin/activate
pip install .

Or, if using uv:

uv sync
source .venv/bin/activate

The sample can then be executed with:

python -m langchain_service_authn

Usage

Usage: python -m langchain_service_authn [OPTIONS] PROMPT

Options:
  --google-drive-folder-id TEXT  The ID of the Google Drive folder to fetch
                                 documents from.  [required]
  --vault-item-id TEXT           The item ID of the Google Drive credentials
                                 in Pangea Vault.  [required]
  --vault-token SECRET           Pangea Vault API token. May also be set via
                                 the `PANGEA_VAULT_TOKEN` environment
                                 variable.  [required]
  --pangea-domain TEXT           Pangea API domain. May also be set via the
                                 `PANGEA_DOMAIN` environment variable.
                                 [default: aws.us.pangea.cloud; required]
  --model TEXT                   OpenAI model.  [default: gpt-4o-mini;
                                 required]
  --openai-api-key SECRET        OpenAI API key. May also be set via the
                                 `OPENAI_API_KEY` environment variable.
                                 [required]
  --help                         Show this message and exit.

For this example, we have various text documents from an Engineering department and a Finance department in a Google Drive folder.

python -m langchain_service_authn --google-drive-folder-id 1Kj77... --vault-item-id pvi_... "What is the top salary in the Engineering department?"

The top salary in the Engineering department is $130,000, earned by Michael Brown, who holds the position of System Architect.