This article will guide you through the process of setting up a Cloudflare Worker to send notifications to LINE Notify. You'll use a pre-existing access token and configure a webhook to trigger the notification process.

Prerequisites

Before you begin, ensure you have the following:

• A LINE Notify access token. (https://notify-bot.line.me/)
• A Cloudflare account with a configured Cloudflare Worker.

Step-by-step guide

1. Login LINE notify to get the access token
2. Click Generate token

1. Select a group chat or 1:1 chat room
2. Click Generate token
3. Copy your token
4. Go to Cloudflare workers and deploy with the following code

addEventListener('fetch', event => {
    event.respondWith(handleRequest(event.request));
});
 
async function handleRequest(request) {
    if (request.method === 'POST') {
        try {
            const headers = Object.fromEntries(request.headers.entries());
            console.log('Request headers:', headers);
        const body = await request.json();
        console.log('Request received:', body);

        const accessToken = '<YOUR_ACCESS_TOKEN>'; // Using the provided access token

        const response = await sendLineNotification(accessToken, body.text);
        const result = await response.json();
         
        return new Response(JSON.stringify(result), { status: response.status });
    } catch (error) {
        console.error('Server error:', error);
        return new Response('Internal Server Error', { status: 500 });
    }
} else {
    console.log('Invalid method');
    return new Response('Method Not Allowed', { status: 405 });
}

}
async function sendLineNotification(accessToken, message) {
    const url = 'https://notify-api.line.me/api/notify';
    const params = new URLSearchParams();
    params.append('message', message);
const response = await fetch(url, {
    method: 'POST',
    headers: {
        'Content-Type': 'application/x-www-form-urlencoded',
        'Authorization': `Bearer ${accessToken}`
    },
    body: params.toString()
});

return response;

}

1. Publish Cloudflare workers and copy the route domain or go with custom domain if you like.
2. Go to Cloudflare Notify
3. Put URL from the worker domain or custom domain in step 11 add route to "/webhook" path. E.g. (https://cloudflare-line-webhook.example.workers.dev/webhook)
4. Click "Save and Test"

You will get the LINE test notification message:

Tips and Considerations

• Security: Ensure that the Worker is secured and only receives requests from trusted sources. (Create custom firewall rules)
• Avoid Hard-Coding Sensitive Information: Hard-coding sensitive data like access tokens directly into your code can lead to security vulnerabilities. Instead, use Cloudflare Workers KV to securely store and retrieve such information.
• Error Handling: Implement additional error handling and logging to capture any issues that arise during the notification process.
• Rate Limits: Be aware of LINE Notify's API rate limits when sending multiple notifications.