TL;DRTo integrate Contentful webhooks with ngrok:
  1. Launch your local app that will process Contentful webhook requests npm start
  2. Launch ngrok ngrok http 3000
  3. Configure Contentful webhooks with your ngrok URL
This guide covers how to use ngrok to route Contentful Webhooks to your localhost app for development and integration testing. Contentful webhooks can be used to notify an external application whenever specific events occur in your Contentful account. By integrating ngrok with Contentful, you can:
  • Develop and test Contentful webhooks locally, eliminating the time in deploying your development code to a public environment and setting it up in HTTPS.
  • Inspect and troubleshoot requests from Contentful in real-time via the inspection UI and API.
  • Modify and Replay Contentful webhook requests with a single click and without spending time reproducing events manually in your Contentful account.
  • Verify signed Contentful webhook requests at the edge using ngrok’s traffic policy with webhook verification

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Step 1: Start your app

For this tutorial, we’ll use the sample NodeJS app available on GitHub. To install this sample, run the following commands in a terminal: 
git clone https://github.com/ngrok/ngrok-webhook-nodejs-sample.git
cd ngrok-webhook-nodejs-sample
npm install
This will get the project installed locally. Now you can launch the app by running the following command: 
npm start
The app runs by default on port 3000. You can validate that the app is up and running by visiting http://localhost:3000. The application logs request headers and body in the terminal and responds with a message in the browser.

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Step 2: Launch ngrok

Once your app is running successfully on localhost, let’s get it on the internet securely using ngrok!
  1. If you’re not an ngrok user yet, just sign up for ngrok for free.
  2. Download the ngrok agent.
  3. Go to the ngrok dashboard and copy your Authtoken.
    Tip: The ngrok agent uses the auth token to log into your account when you start a tunnel.
  4. Start ngrok by running the following command: 
    ngrok http 3000
    Or with Contentful Webhook Request Verification enabled:
    1. Create a traffic policy file named contentful_policy.yml: 
      on_http_request:
  - actions:
      - type: verify-webhook
        config:
          provider: contentful
          secret: "<webhook signing secret>"
    2. Start ngrok with traffic policy: 
      ngrok http 3000 --traffic-policy-file contentful_policy.yml
  5. ngrok will display a URL where your localhost application is exposed to the internet (copy this URL for use with Contentful). ngrok agent running

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Step 3: Integrate Contentful

To register a webhook on your Contentful account follow the instructions below:
  1. Access the Contentful site and sign in using your Contentful account.
  2. On the home page, click Settings on the top meu, click Webhooks, and then click Add Webhook.
  3. On the Webhook page, enter a name in the Name field and enter the URL provided by the ngrok agent to expose your application to the internet in the URL field (i.e. https://1a2b-3c4d-5e6f-7g8h-9i0j.ngrok.app). URL to Publish
  4. Make sure the Active switch is selected and Trigger for all events is selected under the Triggers section.
  5. Select application/json as the Content type value and then click Save.

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Run Webhooks with Contentful and ngrok

Contentful sends different request body contents depending on the event that is being triggered. You can select specific triggering events during the webhook configuration. To trigger Contentful calls to your application follow the instructions below:
  1. Access the Contentful site and sign in using your Contentful account.
  2. On the home page, click Media on the top meu, click Add Asset, and then click Single asset.
  3. On the Asset page, drag and drop an image from your desktop to the File area, and then click Publish. Confirm your localhost app receives two event notifications and logs both headers and body in the terminal.
Optionally, you can verify the log of the webhook call in Contentful:
  1. On the home page the Contentful site, click Settings on the top meu, click Webhooks, click the name of your webhook, and then click the Activity log tab. Webhook Logs

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Inspecting requests

ngrok’s Traffic Inspector captures all requests made through your ngrok endpoint to your localhost app. Click on any request to view detailed information about both the request and response.
By default, accounts only collect traffic metadata to avoid exposing secrets. You must enable full capture in the Observability section of your account settings to capture complete request and response data.
Use the traffic inspector to:
  • Validate webhook payloads and response data
  • Debug request headers, methods, and status codes
  • Troubleshoot integration issues without adding logging to your app

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Replaying requests

Test your webhook handling code without triggering new events from your service using the Traffic Inspector’s replay feature:
  1. Send a test webhook from your service to generate traffic in your Traffic Inspector.
  2. Select the request you want to replay in the traffic inspector.
  3. Choose your replay option:
    • Click Replay to send the exact same request again
    • Select Replay with modifications to edit the request before sending
  4. Modify the request (optional): Edit any part of the original request, such as changing field values in the request body.
  5. Send the request by clicking Replay.
Your local application will receive the replayed request and log the data to the terminal.