How to configure webhooks to get notified of new PDF form submissions

This example showcases the use of a Node.js server to handle incoming webhooks from SimplePDF.

It saves in memory all "submission.created" events and surfaces the submission in a table view.

Clicking on each submission URL opens up the SimplePDF viewer for this specific submission

A live demo can be seen here: https://webhooks.simplepdf.com

This guide explains how to deploy the SimplePDF webhooks example to Cloudflare Workers (Free Plan compatible).

• Node.js installed
• Cloudflare account (free plan works)
• Wrangler CLI installed

npm install

npx wrangler login

This will open a browser window to authenticate with your Cloudflare account.

Create a KV namespace to store webhook events:

npx wrangler kv:namespace create "SIMPLEPDF_WEBHOOKS_KV"

This will output something like:

Created namespace with id "abc123def456"

Copy the namespace ID and update wrangler.toml:

[[kv_namespaces]]
binding = "SIMPLEPDF_WEBHOOKS_KV"
id = "YOUR_KV_NAMESPACE_ID"  # Replace with your actual ID

Edit wrangler.toml to customize the company identifier:

[vars]
COMPANY_IDENTIFIER = "your-company-name"

npm run deploy

Your worker will be deployed and you'll receive a URL like:

https://simplepdf-webhooks.YOUR_SUBDOMAIN.workers.dev

Run the worker locally for testing:

npm run dev

This will start a local development server at http://localhost:8787

The worker automatically cleans up submissions older than 15 minutes. The cron schedule is configured in wrangler.toml:

[triggers]
crons = ["*/15 * * * *"]  # Runs every 15 minutes

Available environment variables in wrangler.toml:

• COMPANY_IDENTIFIER: Your SimplePDF company identifier (default: "webhooks-playground")

The Cloudflare Workers version has these key differences:

1. Storage: Uses Cloudflare KV instead of in-memory arrays
2. Cleanup: Uses Cron Triggers instead of setInterval
3. Runtime: Uses Service Worker API instead of Express
4. Stateless: Each request is independent, no shared state

• GET / - Lists all submissions
• GET /submissions/:id - View specific submission details
• POST /webhooks - Receive webhook events from SimplePDF
• GET /flush - Clear all submissions

Events are stored in KV with keys: submission:{submissionId}

Each value is a JSON string containing the full webhook event payload.

A cron trigger runs every 15 minutes to delete submissions older than 15 minutes.