This project is based on Create React App.

You can follow the docs there to see the full docs on Create React App.

The main addition is a new folder: src/lambda. Each js file in there will automatically be deployed and routed as an AWS lambda function by Netlify's continuous deployments.

As an example, we've included a small src/lambda/hello.js function, which will be deployed to /.netlify/functions/hello.

Each function must export a handler( event, context, callback ) (eaxtly as if the Lambda had been configured with AWS's API Gateway).

The event object looks like:

{
    "path": "/.netlify/functions/hello",
    "httpMethod": "GET"
    "headers": {...}
    "queryStringParameters": {...}
    "body": "Request Body"
    "isBase64Encoded": "A boolean flag to indicate if the applicable request payload is Base64-encode"
}

our handler should use the callback to return either an error (as the first parameter) or a response object:

{
    "isBase64Encoded": true|false,
    "statusCode": httpStatusCode,
    "headers": { "headerName": "headerValue", ... },
    "body": "..."
}

Here’s a simple example function hello.js:

exports.handler = function(event, context, callback) {
  callback(null, {
    statusCode: 200,
    body: "Hello, World"
  });
}

Babel/Webpack compilation

All functions are compiled with webpack using the Babel Loader, so you can use modern JS, import npm modules, etc, without any extra setup.

Local Development

Before developing, clone the repository and run yarn from the root of the repo.

Then open one terminal tab and run:

yarn start

This will start the normal create-react-app dev server and open your app at http://localhost:3000

Then open a separate terminal tab and run:

yarn start:lambda

This will open a local server running at http://localhost:9000 serving your lambda functions.

Requests to http://localhost:3000/.netlify/functions/* will automatically be proxied to the lambda dev server.