LINE Message Types

Engage Studio supports multiple LINE message types in One-off Campaigns. This page describes the available message types, their configuration fields, validation rules, and personalization options.

Each campaign delivery can include up to 5 message objects in a single bundle. All messages in the bundle are delivered together in a single LINE Messaging API call. Recipients receive them as a sequence of messages in the LINE chat.

When a message object in the bundle fails (for example, due to a text length violation), that individual object is recorded as failed. Other messages in the same bundle that succeed are recorded separately.

• Promotional announcements and time-sensitive notifications
• Personalized greetings and loyalty status updates
• Coupon codes and discount descriptions
• Follow-up messages after a purchase or registration

Character limit: LINE enforces a 5,000-character limit on Text v2 messages. Because Liquid variables are expanded at delivery time, character count validation is not enforced at authoring time. If the expanded text exceeds 5,000 characters for a given profile, LINE rejects that message. The rejection is recorded in the delivery log for that profile.

Text messages support Liquid template syntax. Variables are expanded per profile at delivery time.

Common variables:

{{ profile.first_name }}
{{ profile.last_name }}
{{ profile.loyalty_tier }}
{{ profile.coupon_code }}

Default values (used when the profile attribute is null or empty):

{{ profile.first_name | default: "Customer" }}

Conditional content — use if/else/endif tags to show different text based on profile attributes:

• Condition: {%- if profile.loyalty_tier == "gold" -%}
• True branch: Exclusive Gold Member Offer: {{ profile.offer_text }}
• False branch ({%- else -%}): Check out our latest campaign!
• Close: {%- endif -%}

The following LINE Text v2 API features are not supported in the current release and are planned for future milestones:

• Mention substitution — Mentioning LINE users by handle
• LINE Emoji — LINE-native emoji codes (Unicode emoji in plain text are supported)
• Advanced substitution objects — Custom substitution schemas beyond Liquid variable expansion

An Imagemap message displays a single banner image with one or more tappable regions overlaid on it. Each region is a rectangular tap area that can open a URL, send a message, or copy text to the clipboard when tapped. Because the entire message is rendered as an image, Imagemap is well-suited for visually rich promotions where layout and branding are important.

Imagemap messages are delivered as a single image in the LINE chat. Recipients tap a region to trigger the configured action — no text labels are shown on the image itself, so the visual design must communicate the intent of each tap area clearly.

• Promotional banners with multiple tappable call-to-action areas (e.g., "Shop Now", "Learn More", "View Recipe")
• Product showcase images with individual product links
• Event announcements with registration and detail links
• Campaign landing page promotions using a single banner image

Each tap area defines a rectangular region on the Imagemap and the action triggered when a user taps it.

Action types:

Overlapping tap areas are allowed. When areas overlap, the topmost area in the list takes precedence.

Tap area coordinates are defined in a 1040 × height pixel space matching the uploaded image dimensions:

(0,0) ─────────────────────── (1040,0)
  │                                │
  │         Image Canvas           │
  │                                │
(0,height) ──────────────── (1040,height)

Example — a banner split into two equal vertical halves:

The editor validates the following at save time:

• baseUrl is present and uses HTTPS
• altText is present
• baseSize.width equals exactly 1040
• baseSize.height is a positive integer
• At least one tap area is defined
• All tap area fields are non-negative integers
• Each tap area has a valid action type and value

Engage Studio supports LINE Flex Messages for rich, highly customizable layouts.

Paste a JSON payload conforming to LINE's Flex Message schema into the message editor. The editor validates that altText is present and that the contents block is a valid bubble or carousel.

Ready-to-use JSON templates are available in the Flex Message Template Gallery.

The following message types are planned for a future Engage Studio release and are not available currently:

For customers with specific requirements for these message types, contact your customer success representative to discuss timeline and availability.

• Create a One-off LINE Campaign
• Click Tracking
• Testing LINE Campaigns
• LINE Messaging API Reference