Use in production

Here’s a markdown documentation page that shows how to build a Node.js TypeScript backend API for answering business questions using Ax:

Building a Business Q&A API with Ax and Node.js

This guide demonstrates creating a Node.js TypeScript backend API to answer business questions using the Ax library. The API will utilize OpenAI for natural language processing and Weaviate as a vector database for efficient information retrieval.

Table of Contents

1. Project Initialization
2. Code Implementation
3. Docker Image Creation
4. Building and Deploying to Google Cloud Run
5. Secrets Management

Project Initialization

To get started, follow these steps to set up your project:

1. Create a new directory for your project:

   mkdir business-qa-api && cd business-qa-api

2. Initialize a new Node.js project:

   npm init -y

3. Install the necessary dependencies:

   npm install @ax-llm/ax hono tsx dotenv
   npm install --save-dev typescript @types/node

4. Create a tsconfig.json file:

   npx tsc --init

5. Create a src directory and an index.ts file inside it:

   mkdir src && touch src/index.ts

6. Create a .env file in the root directory to store your environment variables:

   touch .env

Code Implementation

Add the following code to your src/index.ts file:

import { AxAI, AxDBManager, AxDBWeaviate, AxRAG } from '@ax-llm/ax';
import { Hono } from 'hono';

// Initialize the AI with the API key
const ai = new AxAI({
  name: 'openai',
  apiKey: process.env.OPENAI_APIKEY as string
});

// Initialize a vector db
const db = new AxDBWeaviate({
    apiKey: process.env.WEAVIATE_APIKEY as string,
    host: process.env.WEAVIATE_HOST as string
});

// Manager for handling database operations with AI
const manager = new AxDBManager({ ai, db });

// Function to fetch answers from the vector database
const fetchFromVectorDB = async (query: string): Promise<string> => {
  const matches = await manager.query(query);
  return (
    matches
      .at(0)
      ?.slice(0, 3)
      ?.map((match) => match.text)
      ?.join('\n') ?? 'No answers found'
  );
};

// Initialize Hono app
const app = new Hono();

// Endpoint to get questions and return answers
app.post('/get-answer', async (c) => {
  // RAG instance for processing queries using recursive answers generation
  const rag = new AxRAG(ai, fetchFromVectorDB, { maxHops: 1 });

  // Extract question from request body
  const question = c.req.body.question;

  // Validate question presence
  if (!question) {
    return c.json({ error: 'Question is required' }, 400);
  }

  try {
    // Process the question using RAG
    const answer = await rag.forward({ question });

    // Return the answer in JSON format
    return c.json({ answer });
  } catch (error) {
    // Handle possible errors
    return c.json({ error: 'Failed to fetch answer' }, 500);
  }
});

// Start the server
app.listen({ port: 3000 });

To run the application, use the following command:

node --env-file=.env --import=tsx src/index.ts

Test your new API

curl -X POST http://localhost:3000/get-answer \
     -H "Content-Type: application/json" \
     -d '{"question": "List 3 of the top most important work done by Michael Stonebraker?"}'

Docker Image Creation

To containerize your application, create a Dockerfile in the root directory:

# Use an official Node.js runtime as the base image
FROM node:18

# Set the working directory in the container
WORKDIR /usr/src/app

# Copy package.json and package-lock.json to the working directory
COPY package*.json ./

# Install the application dependencies
RUN npm install

# Copy the application source code to the working directory
COPY . .

# Expose the port the app runs on
EXPOSE 3000

# Define the command to run the application
CMD ["node", "--env-file=.env", "--import=tsx", "src/index.ts"]

Build the Docker image:

docker build -t business-qa-api .

Building and Deploying to Google Cloud Run

1. Install and set up the Google Cloud SDK.

2. Authenticate with Google Cloud:

   gcloud auth login

3. Set your project ID:

   gcloud config set project YOUR_PROJECT_ID

4. Build and push the Docker image to Google Container Registry:

   gcloud builds submit --tag gcr.io/YOUR_PROJECT_ID/business-qa-api

5. Deploy to Google Cloud Run:

   gcloud run deploy business-qa-api \
     --image gcr.io/YOUR_PROJECT_ID/business-qa-api \
     --platform managed \
     --region us-central1 \
     --allow-unauthenticated

Secrets Management

For managing secrets in Google Cloud Run:

1. Store your secrets in Google Secret Manager:

   echo -n "your-openai-api-key" | gcloud secrets create OPENAI_APIKEY --data-file=-
   echo -n "your-weaviate-api-key" | gcloud secrets create WEAVIATE_APIKEY --data-file=-
   echo -n "your-weaviate-host" | gcloud secrets create WEAVIATE_HOST --data-file=-

2. Grant the Cloud Run service account access to the secrets:

   gcloud run services update business-qa-api \
     --set-secrets=OPENAI_APIKEY=OPENAI_APIKEY:latest,WEAVIATE_APIKEY=WEAVIATE_APIKEY:latest,WEAVIATE_HOST=WEAVIATE_HOST:latest

3. Update your Dockerfile to use the secrets:

   # ... (previous Dockerfile content)
   
   # Use secrets in the command
   CMD ["sh", "-c", "OPENAI_APIKEY=$OPENAI_APIKEY WEAVIATE_APIKEY=$WEAVIATE_APIKEY WEAVIATE_HOST=$WEAVIATE_HOST node --import=tsx src/index.ts"]

4. Redeploy your application to apply the changes.

This setup ensures that your sensitive information is securely managed and accessible to your application in Google Cloud Run.