knorpelsenf / link-preview-bot

Telegram bot to generate link previews for all links in messages.

Link Preview Bot

What is this

This is a tiny Telegram bot (@linkpreviewbot) written in TypeScript that sends all links back to you that were found in your (think: forwarded) message. It can also follow redirects to resolve shortened links. The bot is useful if you want to (see the link preview or) visit the instant view page but the original sender disabled the preview. This happens often when subscribing to newsletter bots. So now you can subscribe to a news bot that does not send instant view pages and forward all interesting messages to @linkpreviewbot to read them with instant view anyway.

Note that instant view pages may circumvent paywalls in some cases, e.g. when the reader is permitted to read only a limited number of articles per day/week/month. Consider buying a subscription from your favorite news page if you feel guilty.

It can also generate messages with link previews for hidden links. This works because Telegram supports sending messages with link previews to websites that are not contained in the message text. Check out the /generate URL command.

How do I run it locally

Make sure you have Deno installed.

git clone [email protected]:KnorpelSenf/link-preview-bot.git
export BOT_TOKEN=your-bot-token
export DEBUG='*' # this will switch to polling+debug logs
deno run --allow-net --allow-env bot.ts

How do I deploy it on Deno Deploy

1. Make sure you have a bot token from @BotFather.
2. Create a project on Deno Deploy.
3. Upload this source code.
4. Store the bot token in an environment variable called BOT_TOKEN.
5. Remember to set the webhook at api.telegram.org to your deployment's URL.

I don't understand X and Y isn't working either

Sorry, I hacked the first version of this in under 24 hours and I no longer bother to work on this. The bot simply does its job, it's convenient, versatile, stable and even highly scalable due to its Cloud Function nature. Contact me on Telegram if there is something about the project that you just cannot figure out on your own. I know that there could be better docs (as always).