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This guide walks you through using ngrok to receive Chargify webhooks on your localhost app. By integrating ngrok with Chargify, you can:
  • Develop and test Chargify webhooks locally without deploying to a public environment or setting up HTTPS.
  • Inspect and troubleshoot requests from Chargify in real time via the inspection UI and API.
  • Modify and replay Chargify webhook requests with a single click instead of reproducing events manually in your Chargify account.
  • Secure your app with Chargify webhook validation provided by ngrok. Invalid requests are blocked by ngrok before reaching your app.

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What you’ll need

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1. Start your app

For this tutorial, you can use the sample Node.js app on GitHub. To install the sample, run the following in a terminal: 
git clone https://github.com/ngrok/ngrok-webhook-nodejs-sample.git
cd ngrok-webhook-nodejs-sample
npm install
Then start the app: 
npm start
The app runs on port 3000 by default. You can confirm it’s running by visiting http://localhost:3000. The app logs request headers and body in the terminal and shows a message in the browser.

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2. Expose your app with ngrok

Once your app is running locally, you’re ready to put it online securely using ngrok.
The ngrok agent uses your authtoken to authenticate when you start a tunnel.
  • Start ngrok: 
    ngrok http 3000
  • Copy the URL ngrok displays. Your app is now exposed at that URL for use with Chargify.

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3. Configure Chargify to send webhooks

Chargify can send webhook requests to your app when events occur in your account. To register for those events:
  • Sign in to Chargify.
  • On the home page, select a site from the Site dropdown at the top.
  • Click Config, Settings, and then Webhooks.
  • On the Webhooks page, click Add New Endpoint.
  • On the Add New Endpoint page, enter your ngrok URL in the Webhook URL field (for example, https://1a2b-3c4d-5e6f-7g8h-9i0j.ngrok.app).
  • Select the Events you want (for this tutorial, select all) and click Add.

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Run webhooks with Chargify and ngrok

Chargify sends different request body contents depending on the event. To trigger new calls from Chargify to your app:
  • On your Chargify site, go to Tools and then Webhook Testing.
  • On the Webhook Testing page, select one of the events you subscribed to, select the webhook, and click Send.
Confirm your localhost app receives the event and logs both headers and body in the terminal. You can verify the webhook call in Chargify: go to Tools, Webhook Panel, and click Details for the webhook call.

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Inspecting requests

ngrok’s Traffic Inspector captures all requests made through your ngrok endpoint to your localhost app. Select any request to view detailed information about both the request and response.
To avoid exposing secrets, accounts only collect traffic metadata by default. 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. (Optional) Modify the request: 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.

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Secure webhook requests

ngrok can verify that incoming requests are from your Chargify webhook so only that traffic reaches your app.
Webhook verification is limited to 500 validations per month on free accounts. If you need more, you can upgrade to Hobbyist or Pay-as-you-go. See TPU Pricing for details.
To add verification:
  • On your Chargify site, click Edit current Site from the Site dropdown at the top.
  • On the Site page, copy the value of the Site Shared Key.
  • Create a Traffic Policy file named chargify_policy.yml. Replace {your site shared key} with the value you copied: 
    on_http_request:
  - actions:
      - type: verify-webhook
        config:
          provider: chargify
          secret: "{your site shared key}"
  • Restart ngrok with the policy file: 
    ngrok http 3000 --traffic-policy-file chargify_policy.yml
  • Go to Webhook Testing and send a new test notification to your webhook.
Your app should receive the request and log it in the terminal.