LINE Messaging API SDK for Ruby

Introduction

The LINE Messaging API SDK for Ruby makes it easy to develop bots using LINE Messaging API, and you can create a sample bot within minutes.

Documentation

See the official API documentation for more information

• English: https://developers.line.biz/en/docs/messaging-api/overview/
• Japanese: https://developers.line.biz/ja/docs/messaging-api/overview/

Also, generated documentation by YARD is available.

• https://line.github.io/line-bot-sdk-ruby/
• https://line.github.io/line-bot-sdk-ruby/_index.html

Requirements

This library requires Ruby 3.2 or later.

Installation

Add this line to your application's Gemfile:

gem 'line-bot-api'

And then execute:

bundle

Or install it yourself as:

gem install line-bot-api

Example projects

We provide examples to help you get started with the SDK. They work in your local environment if you have owned your bot account.

Go the examples directory for more examples.

Synopsis

RBS

This library provides RBS files for type checking.
You can code with type support in the corresponding IDE or editor.

Basic Usage

# app.rb
require 'sinatra'
require 'line-bot-api'

set :environment, :production

def client
  @client ||= Line::Bot::V2::MessagingApi::ApiClient.new(
    channel_access_token: ENV.fetch("LINE_CHANNEL_ACCESS_TOKEN")
  )
end

def blob_client
  @blob_client ||= Line::Bot::V2::MessagingApi::ApiBlobClient.new(
    channel_access_token: ENV.fetch("LINE_CHANNEL_ACCESS_TOKEN")
  )
end

def parser
  @parser ||= Line::Bot::V2::WebhookParser.new(channel_secret: ENV.fetch("LINE_CHANNEL_SECRET"))
end

post '/callback' do
  body = request.body.read
  signature = request.env['HTTP_X_LINE_SIGNATURE']

  begin
    events = parser.parse(body: body, signature: signature)
  rescue Line::Bot::V2::WebhookParser::InvalidSignatureError
    halt 400, { 'Content-Type' => 'text/plain' }, 'Bad Request'
  end

  events.each do |event|
    case event
    when Line::Bot::V2::Webhook::MessageEvent
      case event.message
      when Line::Bot::V2::Webhook::TextMessageContent
        case event.message.text
        when 'profile'
          if event.source.type == 'user'
            profile_response = client.get_profile(user_id: event.source.user_id)
            reply_text(event, "Display name: #{profile_response.display_name}\nStatus message: #{profile_response.status_message}")
          else
            reply_text(event, "Bot can't use profile API without user ID")
          end
        else
          request = Line::Bot::V2::MessagingApi::ReplyMessageRequest.new(
            reply_token: event.reply_token,
            messages: [
              Line::Bot::V2::MessagingApi::TextMessage.new(text: "[ECHO] #{event.message.text}")
            ]
          )
          client.reply_message(reply_message_request: request)
        end
        
      when Line::Bot::V2::Webhook::ImageMessageContent, Line::Bot::V2::Webhook::VideoMessageContent
        response = blob_client.get_message_content(message_id: event.message.message_id)
        tf = Tempfile.open("content")
        tf.write(response)
      end
    end
  end

  # Don't forget to return a successful response
  "OK"
end

Main classes

You may use this classes to use LINE Messaging API features.

Webhook

• Line::Bot::V2::WebhookParser (LINE Developers)
• Line::Bot::V2::Webhook::Event (LINE Developers)

Clients

Class(YARD documentation)	API EndPoint	LINE Developers
Line::Bot::V2::ChannelAccessToken::ApiClient	https://api.line.me/** (related to oauth)	https://developers.line.biz/en/reference/messaging-api/#channel-access-token
Line::Bot::V2::Insight::ApiClient	https://api.line.me/v2/bot/insight/**	https://developers.line.biz/en/reference/messaging-api/#get-insight
Line::Bot::V2::Liff::ApiClient	https://api.line.me/liff/**	https://developers.line.biz/en/reference/liff-server/#server-api
Line::Bot::V2::ManageAudience::ApiClient	https://api.line.me/v2/bot/audienceGroup/**	https://developers.line.biz/en/reference/messaging-api/#manage-audience-group
Line::Bot::V2::ManageAudience::ApiBlobClient	https://api-data.line.me/v2/bot/audienceGroup/**	https://developers.line.biz/en/reference/messaging-api/#manage-audience-group
Line::Bot::V2::MessagingApi::ApiClient	https://api.line.me/v2/bot/**	https://developers.line.biz/en/reference/messaging-api/ https://developers.line.biz/en/reference/partner-docs/
Line::Bot::V2::MessagingApi::ApiBlobClient	https://api-data.line.me/v2/bot/**	https://developers.line.biz/en/reference/messaging-api/
Line::Bot::V2::Module::ApiClient	https://api.line.me/v2/bot/** (related to module)	https://developers.line.biz/en/reference/partner-docs/#module
Line::Bot::V2::ModuleAttach::ApiClient	https://manager.line.biz/module/auth/v1/token/**	https://developers.line.biz/en/reference/partner-docs/#module
Line::Bot::V2::Shop::ApiClient	https://api.line.me/shop/**	https://developers.line.biz/en/reference/partner-docs/#mission-stickers

Use HTTP Information

You may need to store the x-line-request-id header obtained as a response from several APIs.
In this case, please use *_with_http_info methods. You can get headers and status codes.
The x-line-accepted-request-id or content-type header can also be obtained in the same way. Note header name must be lowercase.

push_request = Line::Bot::V2::MessagingApi::PushMessageRequest.new(
  to: event.source.user_id,
  messages: [
    Line::Bot::V2::MessagingApi::TextMessage.new(text: "[^Request ID] #{headers['x-line-request-id']}")
  ]
)
_body, _status_code, headers = client.push_message_with_http_info(push_message_request: push_request)

puts headers['x-line-request-id']
puts headers['x-line-accepted-request-id']
puts headers['content-type']

Error handling

If an API call fails, the SDK does not generate an Error in Ruby; use the status code for proper error handling. Error details are stored in body.

require 'json'
require 'line-bot-api'

def client
  @client ||= Line::Bot::V2::MessagingApi::ApiClient.new(
    channel_access_token: ENV.fetch("LINE_CHANNEL_ACCESS_TOKEN"),
  )
end

def main
  dummy_message = Line::Bot::V2::MessagingApi::TextMessage.new(
    text: "Hello, world!",
  )

  valid_request = Line::Bot::V2::MessagingApi::ValidateMessageRequest.new(
    messages: [dummy_message, dummy_message, dummy_message, dummy_message, dummy_message],
  )
  body, status_code, _headers = client.validate_push_with_http_info(validate_message_request: valid_request)
  handle_response(body, status_code)

  invalid_request = Line::Bot::V2::MessagingApi::ValidateMessageRequest.new(
    messages: [dummy_message, dummy_message, dummy_message, dummy_message, dummy_message, dummy_message],
  )
  body, status_code, _headers = client.validate_push_with_http_info(validate_message_request: invalid_request)
  handle_response(body, status_code)
end

def handle_response(body, status_code)
  case status_code
  when 200
    puts "Valid"
  when 400..499
    puts "Invalid: #{JSON.parse(body)}"
  else
    puts "Other Status: #{status_code}"
  end
end

main

Use with Hash / JSON

You can use Hash instead of the SDK classes. So you can also use Hash parsed from JSON as a parameter.

This is useful, for example, in migrating from v1 or building Flex Message.

But this is not recommended because you lose type checking by RBS.

client = Line::Bot::V2::MessagingApi::ApiClient.new(
  channel_access_token: ENV.fetch("LINE_CHANNEL_ACCESS_TOKEN"),
)

request =  {
  to: "U4af4980629...",
  messages: [
    {
      type: "flex",
      alt_text: "This is a Flex Message",
      contents: {
        type: "bubble",
        body: {
          type: "box",
          layout: "horizontal",
          contents: [
            {
              type: "text",
              text: "Hello"
            }
          ]
        }
      }
    }
  ]
}
client.push_message(push_message_request: request)

# or

request = JSON.parse(
  <<~JSON
    {
      "to": "U4af4980629...",
      "messages": [
        {
          "type": "flex",
          "alt_text": "This is a Flex Message",
          "contents": {
            "type": "bubble",
            "body": {
              "type": "box",
              "layout": "horizontal",
              "contents": [
                {
                  "type": "text",
                  "text": "Hello"
                }
              ]
            }
          }
        }
      ]
    }
  JSON
)
client.push_message(push_message_request: request)

Convert to SDK classes

You can convert Hash / JSON to SDK classes using #create method.

json = <<~JSON
  {
    "to": "U4af4980629...",
    "messages": [
      {
        "type": "flex",
        "alt_text": "This is a Flex Message",
        "contents": {
          "type": "bubble",
          "body": {
            "type": "box",
            "layout": "horizontal",
            "contents": [
              {
                "type": "text",
                "text": "Hello"
              }
            ]
          }
        }
      }
    ]
  }
JSON
request = Line::Bot::V2::MessagingApi::PushMessageRequest.create(
  JSON.parse(json)
)

Versioning

This project respects semantic versioning.

• See https://semver.org/

However, if a feature that was publicly released is discontinued for business reasons and becomes completely unusable, we will release changes as a patch release.

v1 and v2

v1 and v2 are completely different implementations. Migration to v2 is strongly recommended. Please refer to Migration guide for migration procedure.

Media

News: https://developers.line.biz/en/news/

Contributing

Please check CONTRIBUTING before making a contribution.

License

Copyright (C) 2016 LINE Corp.
 
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
 
   http://www.apache.org/licenses/LICENSE-2.0
 
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.