How to Connect LINE Messaging MCP to an AI Agent
Auth setup
1. Go to developers.line.biz. 2. Create Provider > Create Messaging API Channel. 3. Issue channel access token (long-lived). 4. Set webhook URL for receiving messages.
Key facts
| Base URL | https://api.line.me/v2/bot/ |
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| API version | v2 |
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| Auth | Channel Access Token. Create a LINE Messaging API channel in LINE Developers Console. Use the long-lived or stateless channel access token in Authorization: Bearer header. |
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| Token URL | https://api.line.me/oauth2/v3/token |
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| Request body | application/json |
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| Pagination | Not applicable for messaging. For group members: continuationToken param. |
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| Rate limit | Push: 100,000/min. Reply: unlimited. Broadcast: depends on plan (free plan: 200/month total messages). |
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| Error format | JSON: {"message":"The request body has 1 error(s)","details":[{"message":"...","property":"..."}]} |
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Key endpoints
| Method | Path | Description |
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POST | /message/push | Send push message to a user |
POST | /message/reply | Reply to a user message (via replyToken) |
POST | /message/broadcast | Send message to all friends |
GET | /profile/{userId} | Get user profile |
POST | /message/multicast | Send to multiple specific users |
Quickstart
POST /v2/bot/message/push HTTP/1.1
Host: api.line.me
Authorization: Bearer {channel_access_token}
Content-Type: application/json
{"to":"U1234567890abcdef","messages":[{"type":"text","text":"Hello!"}]}
Response: {} (200 OK, empty body on success)
Agent pitfalls & tips
- User IDs start with 'U' and are 33 chars. They're channel-specific — same user has different IDs across channels.
- Reply tokens expire in 1 minute. For async responses, use push message instead of reply.
- Flex Messages (v2): rich interactive layouts. JSON structure is complex — use the Flex Message Simulator to build templates.
- Free plan limits: 200 push messages/month. Development: use reply messages (unlimited) during testing.
- Webhook required: LINE sends user messages to your webhook URL. No polling API for incoming messages.
- Japanese users heavily use LINE — it's the #1 messaging platform in Japan with 96M monthly users.
Source: curated by KanseiLink from official documentation (docs) and registry checks. Last reviewed: 2026-04-04. Specs change — verify against the official docs before production use.
Frequently Asked Questions
What is LINE Messaging MCP's AEO score?
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LINE Messaging MCP has an AEO score of 1.00 and is rated AAA (Best-in-class agent integration). AEO (Agent Engine Optimization) measures how well a SaaS service works with AI agents. Scores range from 0.00 to 1.00, with grades from AAA (best) to D (not agent-ready).
Is LINE Messaging MCP AI-agent-ready?
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LINE Messaging MCP is currently ✓ verified for AI agent use. It offers an official MCP (Model Context Protocol) server, which means AI agents can connect directly. For detailed connection guides, auth setup, and known pitfalls, use the KanseiLink MCP tool.
How does LINE Messaging MCP compare to other Communication services?
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In the Communication category, LINE Messaging MCP is rated AAA. KanseiLink evaluates services based on MCP availability, API quality, documentation, auth-guide clarity, and integration recipe availability (methodology published). Visit the full rankings at kansei-link.com to see how LINE Messaging MCP compares.
How can I integrate LINE Messaging MCP with an AI agent?
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The fastest way to integrate LINE Messaging MCP with an AI agent is through KanseiLink MCP. Install it with: npx @kansei-link/mcp-server — then use the search_services and get_service_detail tools to get the current auth setup, endpoints, rate limits, and agent-specific tips. This data is kept fresh from registry checks, curated official-doc guides, and agent reports.
How do I authenticate with LINE Messaging MCP?
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Channel Access Token. Create a LINE Messaging API channel in LINE Developers Console. Use the long-lived or stateless channel access token in Authorization: Bearer header. Setup: 1. Go to developers.line.biz. 2. Create Provider > Create Messaging API Channel. 3. Issue channel access token (long-lived). 4. Set webhook URL for receiving messages.
What are LINE Messaging MCP's API rate limits?
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Push: 100,000/min. Reply: unlimited. Broadcast: depends on plan (free plan: 200/month total messages).