Wa-chat-server-telegram NPM

wa-chat-server-telegram

wa-chat-server-telegram is a wa-chat-server adapter for the Telegram messenger.

Create a Telegram Bot

Contact BotFather from your Telegram messenger.
Type /newbot and answer the questions.
Save the token for further use.

Adapter Usage

Register The Adapter

An initialization of the wa-chat-server (in a chat application using wa-chat-server to communicate with Watson Assistant) with a wa-chat-server-telegram adapter looks like this:

require('dotenv').config();
import { WAChatServer, Types } from 'wa-chat-server';
import { WAChatServerTelegramAdapter } from 'wa-chat-server-telegram';
const server: WAChatServer = new WAChatServer((process.env as any) as Types.IWAChatServerConfig);
server.addAdapter('telegram', WAChatServerTelegramAdapter);
server.serve();

Configure The Adapter

We must set the following environment variables (e. g. in .env):

Variable	Obligatory	Meaning
`adapter__telegram__token`	Y	The Bot token generated by the BotFather
`adapter__telegram__apiUrl`	Y	The Telegram endpoint, typically https://api.telegram.org)
`adapter__telegram__callbackUrl`	Y	The endpoint to be called by Telegram (without the path `adapters/telegram`
`adapter__telegram__webhookLifetimeS`	N	The Telegram webhook lifetime in seconds. Whenever the lifetime is reached a new webhook URL (containing a random token) is generated. 0 by default which means "generate URL only once at application startup"

Local Development

HTTP Tunnel Setup

For local development we need to set up a secure tunnel localhost and Telegram. We can use ngrok for this purpose:

ngrok http 3023

opens a tunel and gives us a public HTTPS URL to be used by Telegram (without an ngrook account the lifetime of the tunnel will be 2 hours). We must then use the Telegram API to configure this URL in Telegram:

export ENDPOINT="[NGROK_URL]"; export TOKEN=[BOT_TOKEN]; curl -X POST -H "Content-Type:application/json" -d "{\"url\":\"$ENDPOINT/adapters/telegram\"}" "https://api.telegram.org/bot$TOKEN/setwebhook"

We may inspect the communication tunneled by ngrok to localhost on http://localhost:4040.

IMPORTANT: Don't do it for a Telegram bot that is already attached to some server installation. Create your own Telegram bot instead.