Response Tracing for LangChain in Cloudflare Workers

An example Cloudflare Worker demonstrating how to integrate Pangea's Secure Audit Log service into a LangChain app to maintain an audit log of response generations coming from LLMs. This is useful to monitor for hallucinations and leaking sensitive data.

Prerequisites

• Node.js v22.
• A Pangea account with Secure Audit Log enabled with the AI Audit Log Schema Config.
• A Cloudflare account.

Setup

git clone https://github.com/pangeacyber/langchain-js-cloudflare-response-tracing.git
cd langchain-js-cloudflare-response-tracing
npm ci
cp .dev.vars.example .dev.vars

Fill out the following environment variables in .dev.vars:

• CLOUDFLARE_ACCOUNT_ID: Cloudflare account ID.
• CLOUDFLARE_API_TOKEN: Cloudflare API token with access to Workers AI.
• PANGEA_AUDIT_TOKEN: Pangea Secure Audit Log API token.
• PANGEA_AUDIT_CONFIG_ID: Pangea Secure Audit Log configuration ID.

Usage

A local version of the Worker can be started with:

npm start

Then prompts can be sent to the worker via an HTTP POST request like so:

curl -X POST http://localhost:8787 \
  -H 'Content-Type: application/json' \
  -d '"Give me information on John Smith."'

This does not modify the input or output so it's transparent to the LLM and end user.

Audit logs can be viewed at the Secure Audit Log Viewer.