Implement Upvote feature using Cloudflare Workers + KV

07 Sep, 2025

I followed https://github.com/rokcso/post-upvote-api and added the Upvote feature to my site. Now visitors can upvote the blogs and the upvote count and status is displayed. What I did differently with the tutorial was that I went through the steps through C3 and Wrangler instead of Cloudflare dashboard.

Create and Deploy Worker

Create a new Worker project

npm create cloudflare@latest -- post-upvote

For setup,

dannishi@DanniIsWorking cloudflare % npm create cloudflare@latest -- post-upvote

> npx
> "create-cloudflare" post-upvote


────────────────────────────────────────────────────────────────────────────────
👋 Welcome to create-cloudflare v2.52.3!
🧡 Let's get started.
📊 Cloudflare collects telemetry about your usage of Create-Cloudflare.

Learn more at: https://github.com/cloudflare/workers-sdk/blob/main/packages/create-cloudflare/telemetry.md
────────────────────────────────────────────────────────────────────────────────

╭ Create an application with Cloudflare Step 1 of 3
│
├ In which directory do you want to create your application?
│ dir ./post-upvote
│
├ What would you like to start with?
│ category Hello World example
│
├ Which template would you like to use?
│ type Worker only
│
├ Which language do you want to use?
│ lang JavaScript
│
├ Copying template files
│ files copied to project directory
│
├ Updating name in `package.json`
│ updated `package.json`
│
├ Installing dependencies
│ installed via `npm install`
│
╰ Application created 

╭ Configuring your application for Cloudflare Step 2 of 3
│
├ Installing wrangler A command line tool for building Cloudflare Workers
│ installed via `npm install wrangler --save-dev`
│
├ Retrieving current workerd compatibility date
│ compatibility date 2025-10-11
│
├ Do you want to use git for version control?
│ yes git
│
├ Initializing git repo
│ initialized git
│
├ Committing new files
│ git commit
│
╰ Application configured 

╭ Deploy with Cloudflare Step 3 of 3
│
├ Do you want to deploy your application?
│ no deploy via `npm run deploy`
│
╰ Done 

────────────────────────────────────────────────────────────
🎉  SUCCESS  Application created successfully!

💻 Continue Developing
Change directories: cd post-upvote
Start dev server: npm run start
Deploy: npm run deploy

📖 Explore Documentation
https://developers.cloudflare.com/workers

🐛 Report an Issue
https://github.com/cloudflare/workers-sdk/issues/new/choose

💬 Join our Community
https://discord.cloudflare.com
────────────────────────────────────────────────────────────

Replace the source code Replace the code in src/index.js with the code in worker.js. Run the wrangler dev command in the project directory to start a local server and preview the Worker locally at http://localhost:8787/.

npx wrangler dev

You should be seeing

{"code":0,"msg":"Visit https://rokcso.com/p/post-upvote-api/ to see more."}

Deploy the Worker

npx wrangler deploy

Preview your Worker at <YOUR_WORKER>.<YOUR_SUBDOMAIN>.workers.dev.

Create KV namespace and bind it with Worker

npx wrangler kv namespace create upvote-count

Once you run this command, Wrangler will prompt you a few questions and help create the binding to connect Worker with your KV namespace.

🌀 Creating namespace with title "upvote-count"
✨ Success!
To access your new KV Namespace in your Worker, add the following snippet to your configuration file:
{
  "kv_namespaces": [
    {
      "binding": "upvote_count",
      "id": "******"
    }
  ]
}
✔ Would you like Wrangler to add it on your behalf? … yes
✔ What binding name would you like to use? … UPVOTE_COUNT
✔ For local dev, do you want to connect to the remote resource instead of a local resource? … no

Wrangler manage the bindings through wrangler.jsonc file.

"kv_namespaces": [
		{
			"binding": "UPVOTE_COUNT",
			"id": "******"
		}
	]

Create and bind another namespace ‘upvote-record’

npx wrangler kv namespace create upvote-record

Deploy the Worker again with KV namespace

npx wrangler deploy

You should be seeing something like

Your Worker has access to the following bindings:
Binding                                                   Resource          
env.UPVOTE_COUNT (******)       KV Namespace      
env.UPVOTE_RECORD (******)      KV Namespace      

Uploaded post-upvote (2.65 sec)
Deployed post-upvote triggers (1.01 sec)

Go to Cloudflare dashboard, you should be seeing

KV namespace and bindings are successfully created

Update `hugo.toml` to enable upvote

[params]
    upvote = true
    upvoteURL = "The domain name of the Worker that was just deployed/"

Ta-da! Please click the Upvote button below to help me testing 😉

#Danniverse #Dev #Cloudflare

Implement Upvote feature using Cloudflare Workers + KV

Create and Deploy Worker

Create KV namespace and bind it with Worker

Deploy the Worker again with KV namespace

Update hugo.toml to enable upvote

Update `hugo.toml` to enable upvote