AWS Lambda quick start

Use Fauna’s JavaScript driver to query e-commerce demo data using an AWS Lambda function.

Create a database with demo data
Log in to the Fauna Dashboard, and create a database with the following configuration:
- Region group: Choose your preferred region group, which determines where your data resides.
- Use demo data: Enabled.
- Enable backups: Disabled.
Leave the other options as is.
Create an authentication secret
Fauna supports several types of authentication secrets. Create a key, which is a type of secret, with the built-in server-readonly role:
1. In the Dashboard’s Explorer page, select your demo database.
2. In the database’s Keys tab, click Create Key.
3. Choose a Role of server (read-only).
4. Click Save.
5. Copy the Key Secret.
Create the Lambda function
1. Open the Functions page of the Lambda console.
2. Click Create function.
3. Select Author from scratch.
4. In the Basic information pane, for Function name, enter myFaunaLambda.
5. For Runtime, click Node.js 22.x.
6. Leave architecture set to x86_64.
7. Under Additional Configurations, select Enable function URL. Under Auth type, select NONE.
8. Click Create function.
Save the resulting Function URL. You’ll use the URL later.
Set the FAUNA_SECRET environment variable
1. On the function’s page, click the Configuration tab, then click Environment variables.
2. Under Environment variables, click Edit.
3. Click Add environment variable.
4. Enter FAUNA_SECRET as the Key. Paste the key secret you copied earlier as the Value.
5. Click Save.
Initialize a Node.js project
In your local machine’s terminal:
- Create and navigate to a project directory named myFaunaLambda.
- Initialize a Node.js project.
- Install the Fauna JavaScript driver.
mkdir myFaunaLambda cd myFaunaLambda npm init -y npm install fauna

Add code for the Lambda function

In the myFaunaLambda directory, create an index.mjs file and add the following code:

import { Client, fql, FaunaError } from "fauna";

export const handler = async (event) => {
  // Initialize the client to connect to Fauna
  // using the `FAUNA_SECRET` environment variable.
  const client = new Client();

  try {
    // Compose a query using an FQL template string.
    // The query calls the `Product` collection's
    // `sortedByPriceLowToHigh()` index. It projects the `name`,
    // `description`, and `price` fields covered by the index.
    const query = fql`
      Product.sortedByPriceLowToHigh() {
        name,
        description,
        price
      }`;

    // Run the query.
    const pages = await client.paginate(query);

    // Iterate through the results.
    const products = [];
    for await (const product of pages.flatten()) {
      products.push(product);
    }

    return {
      statusCode: 200,
      body: JSON.stringify(products)
    };
  } catch (error) {
    console.error('Fauna Query Error:', error);
    return {
      statusCode: 500,
      body: JSON.stringify({
        error: error instanceof FaunaError ? error.message : 'Unknown error'
      })
    };
  } finally {
    client.close();
  }
};

Package the function
In the myFaunaLambda directory, run the following command to package the function as a ZIP file:
zip -r function.zip .
Upload the function
1. On the Lambda function page, click the Code tab, then click Upload from and select .zip file.
2. Click Upload.
3. Select the function.zip file in the myFaunaLambda directory.
4. Click Save.

Test the function

To test the function, make a GET request to the Function URL you saved earlier. Using curl:

curl <AWS_LAMBDA_FUNCTION_URL> | jq .

The response contains the results of the query:

[
  {
    "name": "single lime",
    "description": "Conventional, 1 ct",
    "price": 35
  },
  {
    "name": "cilantro",
    "description": "Organic, 1 bunch",
    "price": 149
  },
  {
    "name": "limes",
    "description": "Conventional, 16 oz bag",
    "price": 299
  },
  {
    "name": "organic limes",
    "description": "Organic, 16 oz bag",
    "price": 349
  },
  {
    "name": "avocados",
    "description": "Conventional Hass, 4ct bag",
    "price": 399
  },
  {
    "name": "pizza",
    "description": "Frozen Cheese",
    "price": 499
  },
  {
    "name": "cups",
    "description": "Translucent 9 Oz, 100 ct",
    "price": 698
  },
  {
    "name": "taco pinata",
    "description": "Giant Taco Pinata",
    "price": 2399
  },
  {
    "name": "donkey pinata",
    "description": "Original Classic Donkey Pinata",
    "price": 2499
  }
]