Basic Usage

It can be imported with CommonJS, ECMAScript modules(ES modules), and preferably TypeScript.

The library is written in TypeScript and includes TypeScript definitions by default. Nevertheless, it can surely be used with plain JavaScript too.

// ES Modules or TypeScript
import * as line from '@line/bot-sdk';

// CommonJS
const line = require('@line/bot-sdk');

Configuration

For the usage of webhook and client, LINE channel access token and secret are needed. About issuing the token and secret, please refer to Getting started with the Messaging API.

new line.messagingApi.MessagingApiClient({
  channelAccessToken: 'YOUR_CHANNEL_ACCESS_TOKEN',
});
line.middleware({
  channelSecret: 'YOUR_CHANNEL_SECRET'
});

Synopsis

Here is a synopsis of echoing webhook server with Express:

import * as line from '@line/bot-sdk'
import express from 'express'

// create LINE SDK config from env variables
const config = {
  channelSecret: process.env.CHANNEL_SECRET,
};

// create LINE SDK client
const client = new line.messagingApi.MessagingApiClient({
  channelAccessToken: process.env.CHANNEL_ACCESS_TOKEN
});

// create Express app
// about Express itself: https://expressjs.com/
const app = express();

// register a webhook handler with middleware
// about the middleware, please refer to doc
app.post('/callback', line.middleware(config), (req, res) => {
  Promise
    .all(req.body.events.map(handleEvent))
    .then((result) => res.json(result))
    .catch((err) => {
      console.error(err);
      res.status(500).end();
    });
});

// event handler
function handleEvent(event) {
  if (event.type !== 'message' || event.message.type !== 'text') {
    // ignore non-text-message event
    return Promise.resolve(null);
  }

  // create an echoing text message
  const echo = { type: 'text', text: event.message.text };

  // use reply API
  return client.replyMessage({
    replyToken: event.replyToken,
    messages: [echo],
  });
}

// listen on port
const port = process.env.PORT || 3000;
app.listen(port, () => {
  console.log(`listening on ${port}`);
});

The full examples with comments can be found in examples.

For the specifications of API, please refer to API Reference.