Get started with the REST API console

In this getting started exercise, you create a serverless REST API using the API Gateway REST API console. Serverless APIs let you focus on your applications instead of spending your time provisioning and managing servers. This exercise should take less than 20 minutes to complete, and is possible within the AWS Free Tier.

First, you create a Lambda function using the Lambda console. Next, you create a REST API using the API Gateway REST API console. Then, you create an API method and integrate it with a Lambda function using a Lambda proxy integration. Finally, you deploy and invoke your API.

When you invoke your REST API, API Gateway routes the request to your Lambda function. Lambda runs the function and returns a response to API Gateway. API Gateway then returns that response to you.

To complete this exercise, you need an AWS account and an AWS Identity and Access Management (IAM) user with console access. For more information, see Set up to use API Gateway.

Step 1: Create a Lambda function

You use a Lambda function for the backend of your API. Lambda runs your code only when needed and scales automatically, from a few requests per day to thousands per second.

For this exercise, you use a default Node.js function in the Lambda console.

The default Lambda function code should look similar to the following:

export const handler = async (event) => {
    const response = {
        statusCode: 200,
        body: JSON.stringify('The API Gateway REST API console is great!'),
    };
    return response;
};

You can modify your Lambda function for this exercise, as long as the function's response aligns with the format that API Gateway requires.

Replace the default response body (Hello from Lambda!) with The API Gateway REST API console is great!. When you invoke the example function, it returns a 200 response to clients, along with the updated response.

Step 2: Create a REST API

Next, you create a REST API with a root resource (/).

Step 3: Create a Lambda proxy integration

Next, you create an API method for your REST API on the root resource (/) and integrate the method with your Lambda function using a proxy integration. In a Lambda proxy integration, API Gateway passes the incoming request from the client directly to the Lambda function.

Step 4: Deploy your API

Next, you create an API deployment and associate it with a stage.

Now clients can call your API. To test your API before deploying it, you can optionally choose the ANY method, navigate to the Test tab, and then choose Test.

Step 5: Invoke your API

(Optional) Step 6: Clean up

To prevent accruing unnecessary costs to your AWS account, delete the resources that you created as part of this exercise. The following steps delete your REST API, your Lambda function, and the associated resources.