elizaos--eliza/plugins/plugin-line/README.md

@elizaos/plugin-line

LINE Messaging API plugin for elizaOS agents. Enables chatbot integration with LINE, a popular messaging platform in Japan, Taiwan, and Thailand.

Features

• Text Messages: Send and receive text messages
• Rich Messages (Flex): Create visually rich card messages
• Location Messages: Share locations with map pins
• Quick Replies: Provide suggested reply options
• Group/Room Support: Operate in groups and multi-user rooms
• User Profiles: Access user display names, pictures, and language
• Webhook Integration: Receive messages via LINE webhooks

Installation

# npm
npm install @elizaos/plugin-line

# bun
bun add @elizaos/plugin-line

Configuration

Environment Variables

Variable	Description	Required
LINE_CHANNEL_ACCESS_TOKEN	Channel access token from LINE Developers Console	Yes
LINE_CHANNEL_SECRET	Channel secret for webhook verification	Yes
LINE_WEBHOOK_PATH	Webhook endpoint path	No
LINE_DM_POLICY	DM policy: open, pairing, allowlist, disabled	No
LINE_GROUP_POLICY	Group policy: open, allowlist, disabled	No
LINE_ALLOW_FROM	Comma-separated user IDs for allowlist	No
LINE_ENABLED	Enable/disable the plugin	No

Agent Configuration

{
  "plugins": ["@elizaos/plugin-line"],
  "pluginParameters": {
    "LINE_CHANNEL_ACCESS_TOKEN": "your-channel-access-token",
    "LINE_CHANNEL_SECRET": "your-channel-secret",
    "LINE_DM_POLICY": "pairing",
    "LINE_GROUP_POLICY": "allowlist"
  }
}

Setup

1. Create a LINE Developers account at https://developers.line.biz/
2. Create a new Messaging API channel
3. Get your Channel Access Token (issue a long-lived token)
4. Get your Channel Secret
5. Set up webhook URL pointing to your server

Usage

Actions

LINE messaging routes through the canonical MESSAGE action using source: "line".

Primary action	Operation	Description
MESSAGE	send	Send text, flex, or location content to a user, group, or room
MESSAGE	read_channel	Read recent LINE conversation history when available
MESSAGE	list_channels	List recent LINE targets when available

Providers

LINE does not register standalone planner providers. Chat and user context is exposed through the LINE message connector hooks.

LINE ID Formats

• User IDs: Start with U followed by 32 hex characters (e.g., U1234567890abcdef1234567890abcdef)
• Group IDs: Start with C followed by 32 hex characters
• Room IDs: Start with R followed by 32 hex characters

Message Limits

• Text messages: 5000 characters max
• Alt text (for flex/template): 400 characters max
• Location title/address: 100 characters max
• Messages per push: 5 max (batched automatically)

Webhook Setup

1. Configure your webhook URL in the LINE Developers Console
2. Ensure your server verifies webhook signatures using the channel secret
3. The plugin provides middleware for Express-style webhook handling

import { LineService } from "@elizaos/plugin-line";

// Get the middleware
const middleware = lineService.createMiddleware();

// Use with Express
app.post("/webhooks/line", middleware, async (req, res) => {
  const events = req.body.events;
  await lineService.handleWebhookEvents(events);
  res.status(200).end();
});

Flex Messages

LINE Flex Messages allow rich visual content. The plugin supports creating info card bubbles:

const flexMessage = {
  altText: "Update Notification",
  contents: {
    type: "bubble",
    body: {
      type: "box",
      layout: "vertical",
      contents: [
        { type: "text", text: "Title", weight: "bold", size: "xl" },
        { type: "text", text: "Body content", margin: "md", wrap: true }
      ]
    }
  }
};

Security Policies

DM Policies

Policy	Description
open	Accept DMs from anyone
pairing	Accept DMs and remember senders
allowlist	Only accept from LINE_ALLOW_FROM list
disabled	Don't accept any DMs

Group Policies

Policy	Description
open	Respond to anyone in groups
allowlist	Only respond to allowed users
disabled	Don't respond in groups

Development

Building

bun run --cwd plugins/plugin-line build

Testing

bun run --cwd plugins/plugin-line test

API Reference

LineService

Methods

• isConnected(): Check connection status
• getBotInfo(): Get bot profile
• sendMessage(to, text, options?): Send text message
• sendFlexMessage(to, flex): Send flex message
• sendTemplateMessage(to, template): Send template message
• sendLocationMessage(to, location): Send location
• replyMessage(replyToken, messages): Reply using token
• getUserProfile(userId): Get user profile
• getGroupInfo(groupId): Get group info
• leaveChat(chatId, chatType): Leave group/room

License

MIT