AI Assistant for BART (Bay Area Rapid Transit)

This is a simple example of exposing PromptQL to real-time public data using the BART API. The BART API is a public API that provides real-time data on the Bay Area Rapid Transit system. This example demonstrates how to use PromptQL to create a real-time chat application that allows a user to talk to the BART API and get real-time information on departures.

Check out the GitHub repo.

Here's a sample of what you can ask:

• What time is the next train arriving at Embarcadero?
• If I leave 576 Folsom St now, can I make the next train at Montgomery?

Prerequisites

Install the DDN CLI

Minimum version requirements

To use this guide, ensure you've installed/updated your CLI to at least v2.28.0.

macOS and Linux

Simply run the installer script in your terminal:

curl -L https://graphql-engine-cdn.hasura.io/ddn/cli/v4/get.sh | bash

ARM-based Linux Machines

Currently, the CLI does not support installation on ARM-based Linux systems.

Windows

• Download the latest DDN CLI installer for Windows.
• Run the DDN_CLI_Setup.exe installer file and follow the instructions. This will only take a minute.
• By default, the DDN CLI is installed under C:\Users\{Username}\AppData\Local\Programs\DDN_CLI
• The DDN CLI is added to your %PATH% environment variable so that you can use the ddn command from your terminal.

Install Docker

The Docker-based workflow helps you iterate and develop locally without deploying any changes to Hasura DDN, making the development experience faster and your feedback loops shorter. You'll need Docker Compose v2.20 or later.

Validate the installation

You can verify that the DDN CLI is installed correctly by running:

ddn doctor

Setup the Bart API

Step 1: Clone the project

git clone [email protected]:robertjdominguez/example-promptql-bart.git
cd example-promptql-bart

Step 2: Add Anthropic API key to .env

Set up your .env file with your Anthropic (or OpenAI) API key and GitHub API token.

cp .env.example .env

Get an api key from https://console.anthropic.com/settings/keys

# .env
...
...
ANTHROPIC_API_KEY=<your-anthropic-api-key>

To use an OpenAI key instead, you'll have to set OPENAI_API_KEY in your .env file and change the environment variable LLM to openai in the compose.yaml file.

Build your PromptQL app

Now, let's set up the Hasura DDN project with PromptQL to start exploring the data in natural language!

• Set up the Hasura DDN project already scaffolded in the repo:

In the root directory of the repo, run the following commands:

ddn project init

Create a build:

ddn supergraph build local

• Start the DDN project

Let's start the DDN project by executing the following command:

ddn run docker-start

• Open the local DDN Console to start exploring:

ddn console --local

This should open up your browser (or print a browser URL) for displaying the Hasura Console. It’ll typically be something like: https://console.hasura.io/local?engine=localhost:3280&promptql=localhost:3282