Run Your LINE Bot Backend on Cloudflare Workers: Deploy the Worker + Set Up the Official Account Webhook

Why Run Your LINE Bot Backend on Cloudflare Workers?

To make a LINE Official Account “reply on its own,” you need a backend that is online 24/7 and processes messages the instant they arrive. The traditional approach is renting a cloud server — but for individuals or small projects that’s expensive and a hassle to maintain.

Cloudflare Workers makes this simple:

Comparison	Cloudflare Workers	Self-hosted server
Startup speed	Global edge nodes, millisecond cold starts	Pick a data center yourself
Cost	100k requests/day free	Monthly rent at minimum
Maintenance	No OS, no updates to manage	You manage the OS and security
Deploy	One wrangler deploy	SSH and a pile of config
Public URL	HTTPS URL auto-assigned on deploy	Set up your own domain & cert

In short: you only write the message-handling code; Cloudflare handles where it runs, whether it stays up, and the URL. That public HTTPS URL is exactly the Webhook URL LINE uses to push messages to you.

💡 New to the Bot Webhook concept? Start with the Telegram Integration Complete Guide — it walks you through the same flow with the simpler BotFather first.

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Prerequisites

Before you start you’ll need:

1. A LINE Official Account (create one free at LINE Official Account Manager)
2. A Cloudflare account (free plan is fine)
3. Claude Code and wrangler (Cloudflare’s CLI deploy tool) installed locally
4. A Worker script already written (receives LINE messages, calls the AI, returns the result)

The flow has two halves: deploy the backend and get its URL, then go back to the LINE console to paste that URL in and turn on the Webhook.

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Step 1: Deploy the Cloudflare Worker with Claude Code

Open Claude Code in your project directory and have it handle the Cloudflare setup and deploy. A complete deploy usually covers:

1. wrangler login: log into your Cloudflare account
2. Set up KV / R2 storage (if your Bot needs to remember conversations)
3. wrangler secret put: store secrets like the LINE Channel secret encrypted (never hardcode them)
4. wrangler deploy: push it live — when done it returns a Webhook URL

After a successful deploy, the terminal prints a URL like https://your-worker.xxx.workers.dev. Write it down — you’ll paste it into the LINE console shortly.

⚠️ Secrets like the Channel secret and access token should always be stored with wrangler secret put — never commit them to Git.

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Step 2: Open the LINE Official Account Console

Go to LINE Official Account Manager, log in, pick your official account, and land on the home page. Click “Settings” in the top right.

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Step 3: Enable the Messaging API and Grab the Channel Info

In the left menu of the settings page, find Messaging API. Three key pieces of info live here:

• Channel ID: the channel identifier
• Channel secret: the key used to verify request origin (the one you wrangler secret put in the previous step)
• Webhook URL: fill in the Worker URL from Step 1

Fill the Webhook URL field with your Worker URL and click Save.

🚨 Common mistake: the secret doesn’t match If the Bot receives messages but keeps returning 401 / verification failures, the Channel secret stored in your backend usually doesn’t match the one shown here. Go back to Step 1 and re-store it with wrangler secret put.

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Step 4: Turn On Webhook in “Response Settings”

Filling in the URL isn’t enough — you need to tell LINE to hand messages to the Webhook. Go to “Settings → Response settings.” There are a few toggles here; set them like the screenshot below:

• Chat: off (no live human chat)
• Webhook: on (this is the key — only then does LINE POST message events to your Worker)
• Auto-reply messages: leave it on for now; the next step only disables the default canned message

💡 (Optional) Let the Bot be invited into groups: under “Settings → Features,” you can enable “Accept invitations to groups and multi-person chats” so you can later add the Bot to group chats.

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Step 5: Disable the Default Auto-Reply Message

By default LINE has a canned auto-reply that competes with your Bot, so users get two messages. Turn it off.

Under “Auto-reply messages,” switch off the default one.

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Verify It Works

1. Add your official account as a friend on your phone
2. Send any message
3. Within seconds you get a reply processed and returned by your Worker — success!

If nothing happens, use wrangler tail to watch the Worker logs live and see whether messages are arriving and where it’s failing.

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Troubleshooting

🚨 Bot replies twice to one message

The default auto-reply isn’t off (see Step 5), or the response mode is still on “Chat” instead of Webhook (see Step 4).

🚨 Edited the code, but nothing changed on LINE

Cloudflare Workers don’t auto-update — run wrangler deploy again after every change. The Webhook URL stays the same, so no need to touch the LINE console.

🚨 Receiving no messages at all

Check in order: is the Webhook toggle on (Step 4) → is the Webhook URL filled in correctly and saved (Step 3) → use wrangler tail to see whether requests reach the Worker.

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Next Steps

• Want the Bot to remember conversation context? Learn about how AI Agents handle memory
• Want to connect more services (calendar, databases, external APIs)? See how the MCP protocol wires tools into the AI