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LINE Message API Library

This page provides a complete library of LINE Official Account message API payloads for every supported content type. For channel behaviour, recipient addressing, and message counting, see LINE Official Account (Two-way).

Note

Every 8x8 LINE example writes type in Title Case (Text, Image, Video, Audio, Location). The shared /messages OpenAPI schema lists the enum in lowercase, but its own inline example uses Title Case. No available source states that the field is case-insensitive, so use Title Case exactly as shown.

All character, count, and file-size limits on this page are LINE's. No available source states which of them the 8x8 platform pre-validates before forwarding a message to LINE.

Endpoint: POST https://chatapps.8x8.com/api/v1/subaccounts/{subAccountId}/messages

Message TypeAPI Payload

Text​

LINE text message exampleSource: LINE Developers

Send: POST https://chatapps.8x8.com/api/v1/subaccounts/{subAccountId}/messages

View JSON
{
  "user": {
    "channelUserId": "U3d3edab4f36c6292e6d8a8131f141b8b"
  },
  "type": "Text",
  "content": {
    "text": "Hello from 8x8 Messaging API"
  }
}

Key Fields:

  • content.text (required): The message body.

LINE Limits:

  • Maximum 5,000 characters.
  • LINE counts in UTF-16 code units. Emoji and some Kanji count as more than one character.
  • LINE emoji placeholders are replaced with alternative text when counting, so a message containing LINE emoji can exceed the limit unexpectedly.

Image​

LINE image message exampleSource: LINE Developers

Send: POST https://chatapps.8x8.com/api/v1/subaccounts/{subAccountId}/messages

View JSON
{
  "user": {
    "channelUserId": "U3d3edab4f36c6292e6d8a8131f141b8b"
  },
  "type": "Image",
  "content": {
    "url": "https://www.example.com/original.png",
    "image": {
      "thumbnail": "https://www.example.com/thumbnail.png"
    }
  }
}

Key Fields:

  • content.url (required): Public URL of the full-size image.
  • content.image.thumbnail: URL of the thumbnail preview image.

LINE Limits:

ConstraintFull-size imagePreview image
FormatJPEG or PNGJPEG or PNG
Max file size10 MB1 MB
ProtocolHTTPS (TLS 1.2+)HTTPS (TLS 1.2+)
Max URL length2,000 characters2,000 characters

Note: LINE may use the full-size image as the preview instead of the thumbnail you supplied, depending on the device state.

Video​

LINE video message exampleSource: LINE Developers

Send: POST https://chatapps.8x8.com/api/v1/subaccounts/{subAccountId}/messages

View JSON
{
  "user": {
    "channelUserId": "U3d3edab4f36c6292e6d8a8131f141b8b"
  },
  "type": "Video",
  "content": {
    "url": "https://www.example.com/original.mp4",
    "video": {
      "thumbnail": "https://www.example.com/preview.jpg"
    }
  }
}

Key Fields:

  • content.url (required): Public URL of the video file.
  • content.video.thumbnail: URL of the preview image shown before playback.
  • content.video.filesize (optional): Video file size, in bytes.
  • content.video.duration (optional): Duration of the video, in seconds.

LINE Limits:

ConstraintVideo filePreview image
Formatmp4JPEG or PNG
Max file size200 MB1 MB
ProtocolHTTPS (TLS 1.2+)HTTPS (TLS 1.2+)
Max URL length2,000 characters2,000 characters

Note: LINE recommends the video and preview image share the same aspect ratio. A very wide or very tall video may be cropped during playback.

Audio​

LINE audio message exampleSource: LINE Developers

Send: POST https://chatapps.8x8.com/api/v1/subaccounts/{subAccountId}/messages

View JSON
{
  "user": {
    "channelUserId": "U3d3edab4f36c6292e6d8a8131f141b8b"
  },
  "type": "Audio",
  "content": {
    "url": "https://www.example.com/original.mp3",
    "audio": {
      "duration": 300
    }
  }
}

Key Fields:

  • content.url (required): Public URL of the audio file.
  • content.audio.duration (required): Duration of the audio, in seconds.

Important: The 8x8 field is in seconds. LINE's native field is in milliseconds (LINE's example: 60000 for one minute). Do not copy a duration value from LINE's documentation into an 8x8 request.

LINE Limits:

  • Format: mp3 or m4a.
  • Max file size: 200 MB.
  • Protocol: HTTPS (TLS 1.2 or later).
  • Max URL length: 2,000 characters.

Location​

LINE location message exampleSource: LINE Developers

Send: POST https://chatapps.8x8.com/api/v1/subaccounts/{subAccountId}/messages

View JSON
{
  "user": {
    "channelUserId": "U3d3edab4f36c6292e6d8a8131f141b8b"
  },
  "type": "Location",
  "content": {
    "location": {
      "latitude": 1.285651,
      "longitude": 103.847564,
      "name": "8x8 Office Singapore",
      "address": "One George Street, Singapore 049145"
    }
  }
}

Key Fields:

  • content.location.latitude (required): Latitude, as a number.
  • content.location.longitude (required): Longitude, as a number.
  • content.location.name: Location name (maps to LINE's title).
  • content.location.address: Street address.

LINE Limits:

  • Title: maximum 100 characters.
  • Address: maximum 100 characters.

Note: The 8x8 schema marks only latitude and longitude as required, but LINE marks title and address as required too. Supply name and address on every location send.

Media Hosting​

Host your media yourself and pass a publicly reachable HTTPS URL in content.url. Every LINE send example, both in the published usage samples and in 8x8's internal test collection, references an external public URL.

The URL must satisfy LINE's requirements: HTTPS with TLS 1.2 or later, percent-encoded using UTF-8, and no longer than 2,000 characters.

For Developers:

Cross-channel References:

External: