FAQ entries tagged #Messaging API

In Chats mode, click on a rich menu from the Rich Menu pane located on the bottom right to activate it.

Check if you have included "http://" or "https://" in the URL. The link must be in the same URL format as used on browsers.

Message actions will work normally when added to the chat in Chats mode.

The actual LINE chatbot only accepts URLs starting with "https://" to ensure security. LINE Bot Designer doesn't have this limitation to encourage the creation of any chatbot prototype.

The company name displayed on the bottom of the profile page is your Provider name. You can change your Provider name by following these steps:

• For Certified providers (Certified providers have a certified provider badge before their company name)
  You need to submit an application to LINE, so contact your sales representative.
• For non-Certified providers
  From the LINE Developers Console, select provider, click Settings, and from the Provider settings, and click the Edit button under Provider name.
  

*It will take some time before the change of provider name is reflected on your profile page.

See The number of channels that can be created in the LINE Developers Console documentation.

You can find your Channel ID on the LINE Official Account Manager or the LINE Developers Console.

• LINE Official Account Manager (requires Admin role):
  Select account from accounts list and click Settings in the top-right corner of the page. Click Messaging API from the side menu, and you will see your Channel ID next to Channel Info.
  
• LINE Developers Console:
  From the LINE Developers Console, select provider, and then select channel. You can find your Channel ID under Basic settings.
  

You can find your Provider ID on the LINE Developers Console.

• If you have Provider Admin role:
  From the LINE Developers Console, select provider and then click Settings. You can find your Provider ID under Provider settings.
  
• If you don't have Provider Admin role:
  From the LINE Developers Console, select provider. From the page displayed, you will see your Provider ID in the segment after /provider/ in the URL.
  

To report a problem encountered on the LINE Platform or make a request for improvement, contact us using the help center's Inquiry form. Note that we may not be able to respond to all inquiries.

If you need technical support, see How do I contact technical support for inquiring about LINE APIs? in the FAQ.

You can use LINE Profile+ to get a user's phone number. For more information, see LINE Profile+ scopes in the options for corporate customers documentation.

LINE Profile+ is only available to corporate users who have completed certain applications. If you wish you use LINE Profile+, contact your sales representative or contact our Sales partners.

About the user ID issued by a certain provider, in the case that the corresponding LINE account is deleted, the same user ID won't be reused for other LINE accounts within the provider.

For more information on user IDs, see What are the user ID, group ID, and room ID values?

The user ID used by the LINE Platform identifies a user and has the following characteristics:

• The value is generated by the LINE Platform, not by a user. This is different from the LINE ID on LINE used to search for friends.
• Different user IDs are generated based on the provider of the channel. As long as channels have the same provider, regardless of whether the channel is for LINE Login or Messaging API, the same user ID is used for the users of the channels.
• The user ID value is a string that matches the regular expression, U[0-9a-f]{32}.

The group ID used for group chats and the room ID used for multi-person chats are values generated by the LINE Platform to identify group chats and multi-person chats.

The group ID is a string that matches the regular expression, C[0-9a-f]{32}, and the room ID is a string that matches the regular expression, R[0-9a-f]{32}.

User IDs are issued by each channel provider. Once a user ID (userId) is issued for a specific provider, it won't change unless the user deletes their LINE account.

The user ID won't change even if the user transfers their LINE account to another device.

If a user deletes their LINE account and then re-creates a LINE account with the same phone number, the user ID will change.

For more information on user IDs, see What are the user ID, group ID, and room ID values?

You can check the current status of a LINE API outage using these methods:

• Outage report in the news section of the LINE Developers site
• LINE API Status

LINE uses Open Graph Protocol tags from websites to generate URL previews.

The three OGP tags used by LINE:

Example of URL preview:

The behavior depends on the specifications of the OS, such as Android or iOS.

This isn't controlled by the LINE app.

The behavior of converting a URL in a text message to a link depends on the specifications of the OS, such as Android or iOS, and this isn't controlled by the LINE app. For this reason, a URL in a text message may not become a link.

Note that adding a space or a line break before the URL in the text message may be recognized as a valid URL.

Yes, you can. For more information, see Add LINE Official Account in group & multi-person chats in the Messaging API documentation.

You can't block a user who has added your LINE Official Account as a friend.

You can determine with a follow event and an unfollow event of webhook events. There is no endpoint to determine if a user is a friend of your LINE Official Account.

Currently, you can't get the list of group chats and multi-person chats that your LINE Official Account is participating in.

Currently, there is no function to switch the language of messages or rich menus based on the user's language.

Use the Get profile endpoint to get the user's language, and then send messages or set up a per-user rich menu based on the user's language.

No, you can't make the background of rich menus transparent.

You can't use the Messaging API to see how a specific user added your LINE Official Account as a friend.

You can see the friend adding paths statistics, without identifying individual users, in the LINE Official Account Manager. For more information, see Insight analytics - Friends (only available in Japanese) in LINE for Business.

No, you can't.

When the person to whom the LINE Official Account was referred adds them as a friend or unblocks them, a webhook follow event is sent from the LINE Platform to the bot server. However, you can't use the Messaging API to confirm how the user added the LINE Official Account as a friend (i.e., whether the user added the LINE Official Account as a friend through someone's referral).

It is also not possible to confirm the number of people who have friended the LINE Official Account as a result of friend referrals.

You can't use the Messaging API to verify that a message you sent was read. You can get statistics about your sent messages on the following endpoints:

• Get user interaction statistics endpoint
• Get statistics per unit endpoint

You can't send PDF files with the Messaging API.

Using the Messaging API, you can send only the stickers listed in the Stickers.

You can send other stickers using the following methods:

• You can send stickers that you own with your LINE account. To send your own stickers, go to "Chats" in the LINE Official Account Manager or the LINE Official Account Manager App. For more information, see Chats (only available in Japanese) in LINE for Business.
• Only corporate users who have submitted the required applications can send stickers owned by the company such as sponsored stickers or creators' stickers. To send these stickers from your LINE Official Account, contact your sales representative or contact our Sales partners.

Once you've linked your LINE Official Account to a Messaging API channel, you can't un-link your LINE Official Account from the Messaging API channel.

If you want to continue using your LINE Official Account linked to the Messaging API channel, but want to stop using the Messaging API, see Stop using the Messaging API in the Messaging API documentation.

No, you can't unsend or delete your message sent from your LINE Official Account when using the Messaging API.

You also can't cancel the process of sending a message after you have requested to send a message.

Messages sent using the Messaging API may take some time to reach the user.

Messaging requests to each endpoint of the Messaging API are processed asynchronously. For this reason, if a LINE Official Account has many friends, or if there are a large number of requests from other LINE Official Accounts at the same time, it may take some time for the message sending process to be completed.

No, reply messages are not counted towards the message count.

In LINE Official Accounts and the Messaging API, there are various messaging features, but not all message deliveries are counted as part of the message count. Some message deliveries, such as chats and auto-response messages in the LINE Official Account Manager, can be used for free.

• Sending methods that are counted towards the message count
  • Message delivery in the LINE Official Account Manager (including targeted broadcasts and step messages)
  • Push messages, multicast messages, broadcast messages, and narrowcast messages in the Messaging API
• Sending methods that are not counted towards the message count
  • Chats, auto-response messages, and greeting messages in the LINE Official Account Manager
  • Reply messages in the Messaging API

For more information on sending methods that are counted towards the message count, see Chargeable Messages (only available in Japanese) in LINE for Business.

For more information about Messaging API pricing, see Messaging API pricing.

With the Get group chat summary API, you can get the name, and URL of the icon of the group chat that the LINE Official Account is participating in.

To delete the bot, you need to delete your LINE Official Account.

When you get content, the file format of the binary data returned in the response is indicated in the Content-Type header of the response.

By checking the value of the Content-Type header, you can find out the file format of the content. Examples of file format indicated by the Content-Type header are as follows:

To use the Messaging API with your existing LINE Official Account, enable the Messaging API on the LINE Official Account Manager.

For more information, see Enable the Messaging API for your LINE Official Account in the Messaging API documentation.

If you sent a message via the Messaging API and received a status code 2xx, but the user didn't receive the message, the possible reasons are as follows:

• The conditions required for sending a message aren't met, e.g. the user has blocked your LINE Official Account.
  • Conditions for sending push message
  • Conditions for sending multicast message
  • Conditions for sending narrowcast message

If there are no problems with the above, but the LINE app hasn't receive a message, it is possible that for some reason the user's device and the LINE server aren't automatically synchronized. Please refer to the Help Center's "Chats/Calls/Notifications > Chat list information is incorrect > Your chat history differs from what others see" and ask users to try "Repair chat history" from their device using the LINE app.

As stated in the Help Center, users are expected to back up their chat history before manually repairing it.

If you specify a user who doesn't actually receive the message, such as a user ID that blocked the LINE Official Account or a user ID that doesn't exist, the message won't be counted even if you call the API for sending the message.

If you send a message specifying a user who has blocked the LINE Official Account or a user who deleted their account, no error will occur and status code 200 will be returned as a response.

In this case, no message will be sent to the user.

No, the IP address of the LINE Platform from which the webhook request is sent isn't disclosed. For better security, use signature validation instead of access control by IP address.

The number of messages is counted by the number of people to whom the message was sent. In this example, if there are five people in the group chat or multi-person chat where you sent the message, the number of messages counted is five. The number of message objects specified in a single request doesn't affect the number of messages sent.

For message count when you send a message to a user who doesn't receive the message, see If I send a message to a user who doesn't receive the message, is it still counted as one message?.

For more information on pricing, see Messaging API pricing.

Yes.

If multiple message objects are set in the request body when sending a message, the messages will be delivered in the order they are set from the top.

Characters in a text are counted in UTF-16 code units (16-bit). Characters expressed in multiple code units, such as some kanji characters and Unicode emojis, are counted as multiple characters instead of one character.

However, some properties are counted in grapheme cluster units rather than UTF-16 code units. For more information, see Character counting in a text in the Messaging API documentation.

Also, unlike Unicode emojis, LINE emojis provided by LINE are internally converted to the alternative text (e.g., (love)), so they're counted by the number of characters in the alternative text.

Examples of counting the number of characters in UTF-16 code units are as follows:

Message IDs are assigned a value that is unique throughout the Messaging API environment.

It doesn't mean that it's unique for each channel or message type, such as an image.

The order in which messages are displayed depends on how the messages are sent.

If endpoints used for sending messages are executed multiple times, the order in which the endpoints are executed and the order in which the messages will be displayed won't be necessarily the same.

If an endpoint for sending messages is executed once and multiple messages are specified in the request body, the messages will be displayed in the order specified in the request body.

You can find your user ID in the Your user ID of the Basic settings tab of the channel in the LINE Developers Console. For more information, see Developer gets their own user ID in the Messaging API documentation.

Even if a message that contains a video is successfully sent, the video may not play properly on the user's device. If the video doesn't play properly, confirm the following:

• The video must be in a playable file format (mp4).
• The file size of the video must be 200 MB or less.
• The server hosting the video must support HTTP range requests.
• The codec, profile, and level of the video must be set appropriately. *

* If the video doesn't play properly on a particular device, you should take steps such as setting the video codec, profile, and level appropriately. The video might play if you set the video to a setting that is easier for the device to process.

Your account may not have been set up to allow webhooks. To allow webhooks, enable Use webhook on the Messaging API tab of your channel settings on the LINE Developers Console.

It's possible that Allow bot to join group chats setting is disabled on your LINE Official Account, or that another LINE Official Account has already joined the group chat or multi-person chat you invited.

For more information, see Add LINE Official Account in group & multi-person chats in the Messaging API documentation.

Depending response settings on the LINE Official Account Manager, the LINE Official Account will automatically send replies.

Click Edit in Auto-reply messages on the Messaging API tab of your channel settings on the LINE Developers Console to access LINE Official Account Manager and check Response setting.

LINE Official Account will automatically send replies in these cases:

• If Greeting message is set to Enabled, it will automatically send replies when user adds your LINE Official Account as a friend.
• If Auto-response is set to Enabled, it will automatically send replies according to the preset conditions.
• If Chat is set to On, depending on the Chat response method setting, it may automatically send replies.

If a user blocks and then unblocks a LINE Official Account after linking a per-user rich menu, that rich menu will be unlinked from the user.

In this case, if a default rich menu has been set, the default rich menu will be displayed on the user's screen instead. If no default rich menu has been set, the rich menu itself won't be displayed.

There are several reasons why the intended rich menu may not be displayed:

• A rich menu with a higher display priority has been already set
  Rich menus are displayed based on their display priority, not the set date and time. For example, suppose you have set a per-user rich menu. If you then set a default rich menu, the per-user rich menu will be displayed because it has a higher priority than the default rich menu.
  For more information, see When the intended rich menu isn't displayed in the Messaging API documentation.
• The user blocked the LINE Official Account and then unblocked it
  If a user blocks the LINE Official Account after linking a per-user rich menu, and then unblocks the account, that rich menu will be unlinked from the user.
• The developer deleted the rich menu
  If the developer deletes a per-user rich menu, that rich menu will no longer be displayed.
  If a default rich menu is set, the default rich menu will be displayed instead. If no default rich menu has been set, the rich menu itself won't be displayed.

The iPad that created the LINE account or the iPad that took over the LINE account can display rich menus.

Other iPads can't display rich menus.

You can check the LINE settings screen to see if your iPad can display rich menus.

• If Delete Account appears in Settings > Accounts, the iPad can display rich menus.
• If Logout appears in Settings > Accounts, the iPad can't display rich menus.

No, you can't. Take the necessary steps to use these APIs or features.

No, you can't set multiple bot server endpoints in the webhook URL. Only one bot server endpoint can be set in the webhook URL per Messaging API channel.