Registering LINE User ID to Repro

How to register LINE User IDs to Repro

You can register LINE User IDs to Repro using one of the following three methods.

1. Import from the Dashboard

   • Register LINE User IDs in bulk using a CSV file. This is the simplest method for the initial registration.

2. Automatic import via S3

   • By uploading CSV files generated from your CDP or internal systems to S3, Repro automatically imports LINE User IDs.

3. Register via Web/iOS/Android SDK

   • Integrate the Repro SDK into your app or website to send LINE User IDs to Repro in real time based on user actions.

Recommended setup

We recommend starting with an initial import from the Dashboard to register base data,

then combining SDK or S3 import for automatic updates during ongoing operation.

This ensures that the latest LINE User ID information is always synchronized with Repro.

Common Preparation

Preparing LINE User IDs and User IDs

From your CDP or internal systems, export the User ID set via the Repro SDK and the LINE User ID according to the CSV format described below. If you are importing User IDs alongside LINE User IDs, you must link them in advance using Account Linking or similar methods. If you do not need to link Repro User IDs, you can import with a CSV containing only LINE User IDs.

Warning

• The LINE User ID differs from the display name or the LINE ID used for friend search in the LINE app.

CSV Format

The CSV file supports the following two formats.

Format 1: LINE User ID and User ID (Recommended)

line_user_id,user_id
Uxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx,dummy_user_id_000000000001
Uyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy,dummy_user_id_000000000002
...

Format 2: LINE User ID only

line_user_id
Uxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Uyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
...

• Header

  • The first line must contain the header.

  • line_user_id is required. user_id is optional.

• Data contents

  • line_user_id

    • LINE User ID (a 33-character alphanumeric string starting with ‘U’)

    • Required field

  • user_id

    • User ID (The value set as User ID via the SDK)

    • Up to 191 characters

    • Optional field (can be omitted)

• Maximum file size

  • 500 MB

• Character encoding

  • UTF-8 (without BOM)

Import Type

There are two import types for LINE User IDs.

• Import as deliverable users: Import as deliverable users who have added the account as a friend.

• Import as blocked users: Import as blocked users. Blocked users will be excluded from LINE message delivery.

You must specify this import type when importing via either the dashboard or S3 automatic import.

Common Import Patterns

There are several import patterns for LINE User IDs depending on your organization’s system environment and how block information is managed.

Pattern 1: When block information is not stored in your system and only exists in a LINE delivery tool other than Repro

In this pattern, you need to import deliverable users and blocked users separately.

1. Retrieve all users including blocked users from your system or CDP in Format 1 (LINE User ID, User ID), and import them as deliverable users to Repro.

2. Retrieve blocked users from your LINE delivery tool in Format 2 (LINE User ID only), and import them as blocked users to Repro.

Pattern 2: When block information is managed in your own system

In this pattern, import a list with blocked users already excluded.

1. Retrieve users excluding blocked users from your system or CDP in Format 1 (LINE User ID, User ID), and import them as deliverable users to Repro.

Pattern 3: When you do not have blocked user information

In this pattern, use the LINE Messaging API to check block status and import only deliverable users.

1. Retrieve all users from your system or CDP in Format 1 (LINE User ID, User ID).

2. Use the LINE Messaging API’s Get follower IDs API to retrieve a list of friends who have not blocked the account.

3. Compare the lists from steps 1 and 2, and import the list excluding blocked users as deliverable users to Repro.

Note

• For all patterns, you can maintain an up-to-date list of deliverable users by regularly updating user information even after the initial import.

Import Behavior

• When importing as deliverable users with Format 2 (LINE User ID only): Repro User IDs will not be linked. In this case, only broadcast delivery to existing users is available, and segment-based delivery is not possible. To use segment delivery with linked User IDs, please use Format 1.

• When importing as blocked users: For users already imported as deliverable users with Format 1, the block status of those users will be updated.

• Checking block status after import: You can check the block status of individual users by searching with LINE User ID or User ID using ID-specified Audience.

Import from the Dashboard

1. Go to [Settings] > [LINE Settings] > [LINE User Import].

   

2. Select the target LINE channel for the import.

   

3. Under [LINE User ID Import Type], select the Import Type.

4. Select a CSV file and click [Import].

5. Once the uploaded CSV status changes from Uploading to Import Completed, the process is complete.

   

Warning

• The status does not update automatically; please refresh your browser to check the latest status.

• If the status changes to ‘Error’, the error details will be sent to you by email.

  • After correcting the issue based on the error details, please re-import the file.

Automatic import via S3

You can register LINE user information by uploading CSV files to the AWS S3 bucket provided by Repro.

Note

• To use this feature, you need to obtain authentication credentials in advance for uploading objects to the AWS S3 bucket provided by Repro. For more details, please refer to this section.

S3 path structure and explanation of each parameter

Upload in the following format:

Import as deliverable users

s3://repro-data-store/<YOUR_APP_ID>/line_user_id/<line_channel_id>/<year>/<month>/<day>/followed/<file_name>.csv

Import as blocked users

s3://repro-data-store/<YOUR_APP_ID>/line_user_id/<line_channel_id>/<year>/<month>/<day>/unfollowed/<file_name>.csv

Definition of each field

items	Description
<YOUR_APP_ID>	Application ID assigned in the Repro dashboard
<line_channel_id>	Channel ID of the target LINE channel
<year>/<month>/<day>	File upload date. Required in yyyy/mm/dd format
followed / unfollowed	Import type. followed imports as deliverable users. unfollowed imports as blocked users and excludes them from LINE message delivery.
<file_name>	CSV file name to be uploaded

Note

• You can check the <line_channel_id> from Settings > LINE Settings > LINE Channel Settings page.

Warning

• CSV files for upload cannot contain / or whitespace characters in their filename.

CSV Format

Please refer to the CSV Format section for the CSV file format.

Upload Example

For example, when using the AWS CLI, you can upload a CSV file containing LINE users with the following command.

When importing as deliverable users

$ export AWS_ACCESS_KEY_ID=AKIAXXXXXXX
$ export AWS_SECRET_ACCESS_KEY=XXXXXX
$ aws s3 cp line_user_ids.csv s3://repro-data-store/<YOUR_APP_ID>/line_user_id/<line_channel_id>/<year>/<month>/<day>/followed/line_user_ids.csv

When importing as blocked users

$ export AWS_ACCESS_KEY_ID=AKIAXXXXXXX
$ export AWS_SECRET_ACCESS_KEY=XXXXXX
$ aws s3 cp blocked_user_ids.csv s3://repro-data-store/<YOUR_APP_ID>/line_user_id/<line_channel_id>/<year>/<month>/<day>/unfollowed/blocked_user_ids.csv

Import Timing and Frequency

• The import process will automatically start when a file is uploaded to the S3 bucket.

• There are no frequency restrictions, and multiple files can be uploaded in parallel.

  • However, if the S3 path and filename are the same, the first uploaded data may not be processed and the last uploaded data may be processed multiple times. If you want to upload files with the same name on the same day, please change the filenames of each file.

FAQ

• How can I know if the file upload is complete?

  • When the import process is complete, a notification email containing information about the imported LINE user file will be sent. If any errors occur, a download link for the error CSV file will also be included.

• Are year, month, and day all required in the S3 path?

  • All are required. Please specify the file upload date in yyyy/mm/dd format (e.g., 2025/04/30).

• Can I upload another file while uploading to S3?

  • Yes. You can upload multiple files in parallel.

  • However, if the S3 path and filename are the same, the first uploaded data may not be processed and the last uploaded data may be processed multiple times. If you want to upload files with the same name on the same day, please change the filenames of each file.

Register via Web/iOS/Android SDK

You can register LINE User IDs using the SDK from your app or website. With this method, you can obtain a user’s LINE User ID and immediately deliver LINE messages in real time.

For detailed implementation instructions, please refer to the following documentation:

iOS/Android: Registering LINE User ID to Repro (iOS/Android SDK)

Web: Registering LINE User ID to Repro (Web SDK)

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