Exposing your local Rails app with ngrok

Webhooks only work on a public server. But testing webhooks in a staging environment is tedious — ngrok solves this in seconds: it creates an HTTPS tunnel to your local port.

Steps

brew install ngrok/ngrok/ngrok

Grab your token at dashboard.ngrok.com/get-started/setup and configure it:

ngrok config add-authtoken TOKEN

Start the tunnel pointing to your rails server port:

ngrok http 3000

Copy the https://<something>.ngrok-free.app URL that appears and paste it in the provider’s dashboard that will call you (Stripe, Twilio, GitHub, etc).

Caveats

• Hosts: Rails 6+ blocks hosts not listed in config.hosts. Add something like config.hosts << /.*\.ngrok-free\.app/ in config/environments/development.rb.
• HTTPS: The public URL is https, but the local app runs on http. If you use force_ssl, disable it in dev.
• URL changes: Every time ngrok restarts the subdomain changes (on the free plan). Paid accounts allow reserving a fixed subdomain.