sendMessage

This page describes the sendMessage() function in zalo-bot-js, used to send a text message to a user or chat through the SDK.

If your bot needs to reply to incoming text, send notifications, or return workflow results, this is one of the most commonly used functions.

Function signature

sendMessage(
  chatId: string,
  text: string,
  options?: { reply_to_message_id?: string },
): Promise<Message>

When to use it

• reply to an incoming message
• send proactive notifications to a chat_id
• return results from bot logic or workflows
• send content from webhook, polling, or internal services

Parameters

Parameter	Type	Required	Description
chatId	string	Yes	ID of the target user or chat
text	string	Yes	Text message content
options.reply_to_message_id	string	No	Message ID to reply to

Return value

The function returns Promise<Message>.

Minimal example

import "dotenv/config";
import { Bot } from "zalo-bot-js";

const bot = new Bot({ token: process.env.ZALO_BOT_TOKEN! });

async function main() {
  const chatId = process.env.ZALO_CHAT_ID!;
  const message = await bot.sendMessage(chatId, "Hello!");

  console.log(message.messageId);
}

void main();

Example in polling

bot.on("text", async (message) => {
  if (!message.text) {
    return;
  }

  await bot.sendMessage(message.chat.id, `You said: ${message.text}`);
});

Example with reply options

bot.on("text", async (message) => {
  await bot.sendMessage(
    message.chat.id,
    "I received your request.",
    {
      reply_to_message_id: message.messageId,
    },
  );
});

Relationship with replyText()

If you already have a Message, you can also use message.replyText(). Internally, that helper calls sendMessage() with the current chat.id.

Practical notes

• sendMessage() is the SDK-level API that developers should call directly
• it returns a parsed Message model instead of exposing raw transport results

Next

• See replyText for the message helper version.
• See sendPhoto if you want to send images instead of plain text.

Last updated: April 5, 2026