Version: 1.4

Multi-Channel Support

Bottender intends to meet enterprise project needs. So, Bottender supports multiple chat channels in the very early stage. For example, you can put the environment variables of each chat channel in one config file; you can use platform specific routes to organize user events from various platforms.

Plus, Bottender aims to support the full features of each chat channel, e.g., Block Kit of Slack, rich menu of LINE, Handover Protocol of Messenger. And you don't have to learn extra generic chat UIs and worry about if these still apply to the latest chat UI of each chat channel.

The primary three steps to build a basic cross-platform bot are as follows:

Set up each chat channel
Enable each chat channel
Develop cross-platform bot actions

Set Up Each Chat Channel

To build a cross-platform bot, you have to set up each platform first. In short, you have to fill in environment variables in your .env for the chat channels supported by your bot.

# .env

MESSENGER_PAGE_ID=
MESSENGER_ACCESS_TOKEN=
MESSENGER_APP_ID=
MESSENGER_APP_SECRET=
MESSENGER_VERIFY_TOKEN=

WHATSAPP_ACCOUNT_SID=
WHATSAPP_AUTH_TOKEN=
WHATSAPP_PHONE_NUMBER=

LINE_ACCESS_TOKEN=
LINE_CHANNEL_SECRET=

TELEGRAM_ACCESS_TOKEN=

SLACK_ACCESS_TOKEN=
SLACK_VERIFICATION_TOKEN=

VIBER_ACCESS_TOKEN=

Note: If you are not familiar with setting up chat channels, you may refer to the following Bottender docs:
Messenger Setup
WhatsApp Setup
LINE Setup
Slack Setup
Telegram Setup
Viber Setup

Enable Each Chat Channel

Next, you have to make sure you have enable the channel you want to support in bottender.config.js.

For example, if you want to enable your bot to support Messenger, you have to set channels.messenger.enabled as true.

// bottender.config.js

module.exports = {
  channels: {
    messenger: {
      enabled: true,
      path: '/webhooks/messenger',
      pageId: process.env.MESSENGER_PAGE_ID,
      accessToken: process.env.MESSENGER_ACCESS_TOKEN,
      appId: process.env.MESSENGER_APP_ID,
      appSecret: process.env.MESSENGER_APP_SECRET,
      verifyToken: process.env.MESSENGER_VERIFY_TOKEN,
    },
    whatsapp: {
      enabled: true,
      path: '/webhooks/whatsapp',
      accountSid: process.env.WHATSAPP_ACCOUNT_SID,
      authToken: process.env.WHATSAPP_AUTH_TOKEN,
      phoneNumber: process.env.WHATSAPP_PHONE_NUMBER,
    },
    line: {
      enabled: true,
      path: '/webhooks/line',
      accessToken: process.env.LINE_ACCESS_TOKEN,
      channelSecret: process.env.LINE_CHANNEL_SECRET,
    },
    telegram: {
      enabled: true,
      path: '/webhooks/telegram',
      accessToken: process.env.TELEGRAM_ACCESS_TOKEN,
    },
    slack: {
      enabled: true,
      path: '/webhooks/slack',
      accessToken: process.env.SLACK_ACCESS_TOKEN,
      signingSecret: process.env.SLACK_SIGNING_SECRET,
    },
    viber: {
      enabled: true,
      path: '/webhooks/viber',
      accessToken: process.env.VIBER_ACCESS_TOKEN,
      sender: {
        name: 'xxxx',
      },
    },
  },
};

Develop Cross-Platform Bot Actions

Now, you can develop actions to handle messages from different platforms.

A right bot action relates to the current user status with the incoming event. In the following section, you can see various approaches to cross-platform event handling.

Using `context.platform` to Manage Cross-Platform Events

You can use context.platform to check that each message belongs to which platform.

In the following code, you can see a simple action that replies to the users with the platform they are using.

module.exports = async function App(context) {
  await context.sendText(`Hello World. Platform: ${context.platform}`);
};

You can check out the repository of the above example here.

Using `router` and `platform` to Manage Cross-Platform Events

Different platforms provide different advanced events for better user experience. For example, Messenger supports Button Template, while LINE supports Flex Message. Therefore, you might want to define some platform-specific actions to handle these advanced events.

To better organize bot actions, you can use router and platform functions from bottender/router to handle routing among different platforms.

In the example app, you can see two additional actions to leverage the platform-specific events.

import { platform, router } from 'bottender/router';

async function LineAction(context) {
  await context.sendFlex('This is a line-specific message!', {
    type: 'bubble',
    body: {
      type: 'box',
      layout: 'horizontal',
      contents: [
        {
          type: 'text',
          text: 'Hello,',
        },
        {
          type: 'text',
          text: 'World',
        },
      ],
    },
  });
}

async function MessengerAction(context) {
  await context.sendButtonTemplate('This is a messenger-specific message!', [
    {
      type: 'postback',
      title: 'Hello',
      payload: 'Hello',
    },
    {
      type: 'postback',
      title: 'World',
      payload: 'World',
    },
  ]);
}

module.exports = async function App(context) {
  return router([
    platform('line', LineAction),
    platform('messenger', MessengerAction),
  ]);
};

Using Platform Specific Routes to Manage Cross-Platform Events

By Bottender 1.1+, you can use platform specific routes as an alternative to organize events from various chat channels. To learn more about the details of those specific routes, check out their documentation:

Set Up Each Chat Channel​

Enable Each Chat Channel​

Develop Cross-Platform Bot Actions​

Using context.platform to Manage Cross-Platform Events​

Using router and platform to Manage Cross-Platform Events​

Using Platform Specific Routes to Manage Cross-Platform Events​