How to send a message to Telegram from Zapier

Zapier does not offer native integration for Telegram. How can one send a message to Telegram chat from Zapier?

Zapier offers Code actions that can execute JavaScript or Python code. You can use JavaScript fetch and Telegram HTTP API to post messages to Telegram chats through your bot.

// TG bot API documentation https://core.telegram.org/bots/api

// Set up the bot with BotFather and the API token https://telegram.me/BotFather
const TG_API_TOKEN = "xxx";

// Add the bot to a chat
// In chat type: /start to make the bot to recognise the chat 
// Get chat it by calling TG getUpdates API in terminal and picking
// the chat id from the output by hand
//
//  curl https://api.telegram.org/bot$TG_API_TOKEN/getUpdates | jq 
// 
const CHAT_ID = "xxx";

async function postData(url, data) {
  // Default options are marked with *
  const response = await fetch(url, {
    method: 'POST', 
    headers: {
      'Content-Type': 'application/json'
    },
    body: JSON.stringify(data) // body data type must match "Content-Type" header
  });
  return response.json(); // parses JSON response into native JavaScript objects
}

// Create the message using uptick formatting from whatever inputData field 
// you choose in Zapier
const message = `Hello my old friend ${inputData.id}`;

console.log("Sending out", message);

// Create sendMessage payload
const payload = {chat_id: CHAT_ID, text: message, disable_notification: false};

// Which endpoint we are calling
const endpoint = `https://api.telegram.org/bot${TG_API_TOKEN}/sendMessage`;

// Call Telegram HTTP API
const resp = await postData(endpoint, payload);

console.log("We got", resp);

// Zapier scripts needed output - pass Telegram API response
output = resp;