LINE Connect

Dify Endpoint Plugin — Connect any Dify chatbot or agent app to a LINE Official Account in minutes.

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Overview

LINE Connect bridges LINE Messaging API and Dify's chat API. Users chat on LINE; your Dify app answers automatically — with full conversation persistence, image/file support, and a built-in admin dashboard.

Architecture

                         Webhook (POST)
LINE User  ──message──>  LINE Platform  ──────────>  LINE Connect Plugin
                                                         |
                                                    Dify Chat API
                                                    (stream/block)
                                                         |
LINE User  <──reply────  LINE Platform  <──────────  LINE Connect Plugin
                                                         |
                                              Admin Dashboard (GET)
                                                    Browser UI

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Screenshots

Dashboard

Overview of your LINE Connect workspace — total conversations, active users, message activity chart, and system status at a glance.

Conversations

Real-time chat view with message history, bot toggle, tags, notes, and unread indicators.

Analytics

Message volume trends, response time distribution, user growth, and peak hours heatmap.

Settings

Quick reply templates, tag management, bot schedule, broadcast messaging, and storage info.

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Features

Feature	Description
Two-way messaging	Receive LINE messages, forward to Dify, reply automatically
Image support	Users send images via LINE — uploaded to Dify as file variables for vision models
File support	Video, audio, and documents are uploaded and forwarded to Dify
Image debounce	Batch multiple images into a single Dify call (configurable delay)
Display name forwarding	Inject LINE user's display name as a Dify input variable
Markdown to FlexMessage	Render bot replies as rich FlexMessage bubbles with headings, bold, lists, tables, blockquotes
Conversation persistence	Each user/group gets a unique Dify conversation ID
Group & room chat	Works in 1:1, group, and multi-party room chats
Streaming with fallback	Stream-first with automatic blocking fallback for reliability
Multi-endpoint isolation	Each endpoint has its own isolated storage — fully separated
Admin dashboard	Password-protected web UI for managing all conversations
Analytics	Message volume, user growth, response time charts with daily breakdown
Typing indicator	Animated dots in dashboard while bot is processing
Unread badges	Per-chat unread count with visual indicators
Chat management	Custom names, tags, starred chats, notes, search
Broadcast	Send messages to all or starred conversations
Schedule	Working hours configuration with per-chat override
Scalable	Optimized for 1,000+ users with cached index lookups

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Requirements

Requirement	Details
Dify	v0.7.0+ with plugin support enabled
LINE	A LINE Official Account with Messaging API channel
Dify App	A published Chatbot or Agent app with an API key

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Quick Start

Step 1 — LINE Developers Console

1. Go to LINE Developers and create a Messaging API channel (or use an existing one).
2. Copy the Channel Secret from Basic settings.
3. Issue a Channel Access Token from the Messaging API tab.

Step 2 — Dify App

1. Create or open your Dify app (Chatbot or Agent).
2. Publish the app and go to API Access to copy the API key (starts with app-...).

Step 3 — Install the Plugin

1. In Dify, go to Plugins and upload the .difypkg file (download from Releases).
2. Click + to add a new endpoint and fill in the settings:

  

Settings Reference

Setting	Required	Default	Description
Endpoint Name	Yes	—	A name for this endpoint (e.g. BOT)
Channel Secret	Yes	—	LINE Developers > Basic settings
Channel Access Token	Yes	—	LINE Developers > Messaging API
Dify App API Key	Yes	—	Your Dify app's API key (app-...)
Admin Dashboard Password	Yes	—	Password to access the admin web UI
Dify API URL	No	https://api.dify.ai/v1	Change for self-hosted Dify (e.g. http://api:5001/v1)
Pass LINE Display Name	No	True	Forward user's LINE name as an input variable
Display Name Variable	No	displayName	Variable name for the display name in your Dify app
Enable Image Support	No	False	Accept images and files from LINE
Image Variable Name	No	img	Variable name for uploaded images in your Dify app
Image Prompt	No	User sent an image	Query text sent to Dify when user sends an image
Image Debounce (seconds)	No	0	Wait time to batch multiple images (0 = disabled, recommended: 3)
Markdown to FlexMessage	No	False	Render replies as rich FlexMessage bubbles
Strip Markdown	No	True	Remove markdown formatting from bot replies
Debug Mode	No	False	Show error details in LINE replies (for development only)
Welcome Message	No	Welcome!...	Message sent when a user adds the bot as friend
Max Stored Media	No	200	Max media files kept for admin preview
Max Media Storage (MB)	No	800	Max total size for stored media in MB

Step 4 — Set the Webhook URL

After installing, Dify shows the endpoint URLs:

1. Copy the POST URL.
2. In LINE Developers > Messaging API > Webhook URL, paste it.
3. Enable Use webhook.
4. Disable Auto-reply messages in the LINE Official Account Manager.

Step 5 — Admin Dashboard

Open the GET endpoint URL in your browser:

Enter the admin password you configured in Step 3 to access the dashboard.

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Message Types

LINE Message	Behavior	Dify Variable
Text	Forwarded as query	—
Image	Uploaded and forwarded	img (configurable)
Video	Uploaded and forwarded	files
Audio	Uploaded and forwarded	files
File	Uploaded and forwarded	files
Sticker	Ignored silently	—

Image Debounce

When a user sends multiple images at once, each arrives as a separate webhook event. Without debounce, the bot responds to each individually:

Without debounce (0):              With debounce (3):
  Image 1 --> Bot reply 1           Image 1 --> queued
  Image 2 --> Bot reply 2           Image 2 --> queued
  Image 3 --> Bot reply 3           Image 3 --> wait 3s --> Bot reply (all 3)

Set Image Debounce to 3 seconds for the best experience with multi-image uploads.

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User Commands

Command	Action
/clear	Reset conversation and start fresh
/reset	Same as /clear
/new	Same as /clear

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How It Works

Conversation Flow

1. LINE webhook arrives at the plugin's POST endpoint
2. Signature verification using HMAC-SHA256 with Channel Secret
3. Loading animation shown to the user while processing
4. Dify API call with streaming (automatic blocking fallback)
5. Response formatting — strip markdown, split long messages, extract image URLs
6. Reply via LINE Reply API (free) with Push API fallback

Retry Strategy

1. Stream + conversation_id     (fastest, preserves context)
2. Blocking + conversation_id   (different transport, same context)
3. Stream + new conversation    (only if conversation_id seems stale)
4. Blocking + new conversation  (final fallback)

Storage

All storage keys are namespaced per endpoint using a hash of the Channel Secret, so multiple endpoints in the same plugin installation are fully isolated.

Key Pattern	Data	Limit
{ns}_lc_{userId/groupId}	Dify conversation ID	1 per chat
hist_{ns}_lc_{...}	Chat message history	100 messages
{ns}_cidx	Index of all conversations	1,000 entries
img_{messageId}	Stored media files	configurable (default: 200 files / 800 MB)
off_{ns}_lc_{...}	Bot disabled flag	1 per chat

Total plugin storage quota: 1 GB

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Troubleshooting

Problem	Solution
Bot doesn't reply	Check webhook URL is correct and "Use webhook" is enabled in LINE settings
401 error in webhook	Verify Channel Secret and Channel Access Token are correct
Images not working	Enable "Image Support" in settings and add a file input variable in your Dify app
Bot replies multiple times for images	Set Image Debounce to 3 seconds
Admin dashboard won't load	Use the GET endpoint URL (not the POST webhook URL)
Bot not responding in group chat	Make sure the bot is invited to the group and has permission to read messages
Conversation seems to reset	Check Dify app logs — the conversation ID may have expired or been invalidated

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Changelog

See CHANGELOG.md for the full release history.

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License

MIT

Author

suphachok — @DomT00T