zoom-webhook-proxy

A lightweight Node.js proxy that instantly responds to Zoom's 3-second webhook validation and asynchronously forwards the full payload to a Google Apps Script doPost() endpoint for further processing.

Architecture

Zoom api <-(*)-> nginx - zoom-webhook-proxy(Node.js) <- (**) -> Google Apps Script

• (*) due to latency issues, direct connections from Zoom API to Google Apps Script cannot satisfy Zoom's validation requirements. additionally, Zoom does not permit redirects. therefore, the endpoint.url_validation event is processed by zoom-webhook-proxy.
• (**) the proxy forwards x-zm-signature and x-zm-request-timestamp via query string, since these HTTP headers are stripped by the Google Apps Script environment. the proxy also checks whether Google Apps Script returns the same result for endpoint.url_validation. if the response matches, forwarding behavior continues; otherwise, it is suspended until the next validation pass.

Setup

1. Get your Zoom Webhook Secret

Visit Zoom Marketplace and create a Webhook-only app. Copy the Secret Token from the app settings.

2. Install dependencies

npm install express axios dotenv ip-cidr ipaddr.js

3. Configure .env

Copy the example.env file to a .env file and fill the following:

POST_URL="https://script.google.com/macros/s/.../exec"
ZOOM_SECRET="your_zoom_webhook_secret"

• POST_URL: The URL of your Google Apps Script doPost() endpoint
• ZOOM_SECRET: The secret token from your Zoom webhook app

4. Run the proxy server

node index.js

5. Example Nginx configuration

location "/zoom-webhook-proxy" {
  proxy_pass         http://127.0.0.1:3000/zoom-webhook-proxy;
  proxy_http_version 1.1;
  proxy_set_header   Host $host;
  proxy_set_header   X-Real-IP              $remote_addr;
  proxy_set_header   X-Forwarded-For        $proxy_add_x_forwarded_for;
  proxy_set_header   X-Forwarded-Proto      $http_x_forwarded_proto;
  proxy_set_header   X-Zm-Signature         $http_x_zm_signature;
  proxy_set_header   X-Zm-Request-Timestamp $http_x_zm_request_timestamp;
}

Enjoy!