Webhooks Tutorial

In this tutorial, we’ll create a Node.js Express app that handles webhook callbacks and uses ngrok (ngrok.com) to expose the app to the Internet. Then, we’ll create a webhook and observe the callback using the ngrok web interface when the event is triggered.

Prerequisites

• A store or app API account with OAuth scopes that include Information & Settings read-only and Products read-only.
• Webhooks Overview
• Familiarity with working in the terminal
• Familiarity working with node and npm

Create an Express app

First, let’s make a webhooks-test directory and initialize a Node.js Express app inside of it. To do so, run the following commands in the terminal.

mkdir webhooks-test         # Create project directory
cd webhooks-test            # Move into project directory
npm init                    # Initialize a Node.js project (hit return to accept the default values)
touch index.js              # Create main app script file

Then, copy and paste the following JavaScript code into index.js.

const express = require('express');
const ngrok = require('ngrok')
const app = express();
// when there's a post request to /webhooks...
app.post('/webhooks', function (req, res) {
    // respond with 200 OK
    res.send('OK');
});
// listen to port 3000
app.listen(3000, function () {
    console.log('Listening for webhooks on port 3000');
    // start ngrok and create a tunnel to port 3000
    (async function() {
        const url = await ngrok.connect(3000);
    })();
})

Then download and install the latest supported version of ngrok. This app listens to requests on port 3000, then responds with a 200 status once it receives a POST request to /webhooks.

The following commands show the steps to install ngrok using Homebrew.

brew install ngrok/ngrok/ngrok
ngrok config add-authtoken <TOKEN>

Start the app

To start the app, run the following commands:

cd ~/path/to/webhooks-test # Make sure you're in your webhooks-test project directory
ngrok http http://localhost:8080              # Start the app

Navigate to http://localhost:4040/ in your browser. You should see the ngrok web interface like shown in the image below. Copy the HTTPS tunnel URL and keep the app running.

Create a webhook

Now, we’ll create a webhook that subscribes to the store/product/updated webhook event. To do so, send a POST request to /stores/{{STORE_HASH}}/v3/hooks.

POST https://api.bigcommerce.com/stores/{{STORE_HASH}}/v3/hooks
X-Auth-Token: {{ACCESS_TOKEN}}
Accept: application/json
Content-Type: application/json
{
 "scope": "store/product/updated",
 "destination": "https://6a35e97b.ngrok.io/webhooks", # Replace 6a35e97b.ngrok.io with your HTTPS tunnel URL
 "is_active": true
}

Trigger the webhook event

Webhooks fire when shoppers perform actions on the storefront and when users make changes in the control panel. They will also fire when you make changes using an API. Trigger the webhook you just created by performing the following actions in your BigCommerce control panel:

1. Navigate to Products > View.
2. Edit a product and change something like name or description.
3. Click Save.

Now, visit the ngrok web interface address (http://127.0.0.1:4040) and check for a 200 response.

The summary shows the webhook fired and our Express app returned a 200 response along with the text OK. The response is generated by res.send(‘OK') in our app code. For more information, see Express Routing.

Adding custom headers

You can add custom headers to your create webhook request for added security. The headers property accepts any key-value pair as a string. BigCommerce will include the headers in callback requests made to your application.

POST https://api.bigcommerce.com/stores/{{STORE_HASH}}/v3/hooks
X-Auth-Token: {{ACCESS_TOKEN}}
Accept: application/json
Content-Type: application/json
{
  "scope": "store/cart/lineItem/*",
  "destination": "https://myapp.herokuapp.com/",
  "is_active": true,
  "headers": {
    "Authorization": "Basic SGVsbG86R29vZGJ5ZQ=="
  }
}

Troubleshooting

Custom ports

Currently, BigCommerce does not support destination URLs served over custom HTTPS ports. Use the default HTTPS port 443.

Getting a 404 error using the root (/) url?

Add this snippet to your code to respond to incoming GET requests with ‘hello’:

app.get('/',(req, res)=>{
    res.send('Hello!');
});

Getting error “ngrok not found”?

There are two ways to fix this. Your local setup will determine which command will work. Use the command mv ngrok /usr/local/bin to move ngrok to your local bin folder. This way it becomes available globally. Use the command ./ngrok http 3000 to run ngrok as a sudo user.

Windows users

If you are having trouble getting ngrok started, try setting the PATH.

• What are PATH and other environment variables, and how can I set or use them?

Resources

• Webhooks Overview
• Webhook Events
• Webhooks Reference