Line Getting Started: Messaging API Quickstart (2026)

Getting started overview

To begin developing with Line's Messaging API, the process involves several key steps: account creation, setting up a messaging channel, obtaining API credentials, and then executing a basic API request. This guide focuses on enabling a developer to send their first message through the Line platform.

Line's Messaging API facilitates communication with Line users through official accounts, supporting various message types, including text, images, and rich media. It is commonly used for building chatbots, customer service applications, and marketing automation within the Line ecosystem, particularly in Asian markets Line Messaging API overview.

Quick Reference Steps

Create an account and get keys

Access to the Line Messaging API begins with creating a Line Developers account. This account serves as the central point for managing all your Line-related development projects.

1. Register for a Line Developers Account: Navigate to the Line Developers Console and sign in with your existing Line account. If you do not have a Line account, you will need to create one first.
2. Create a Provider: A Provider is an entity that offers services on the Line Platform. You can create a new Provider from the Providers list within the console. Give your Provider a descriptive name.
3. Create a Messaging API Channel: Within your newly created Provider, select the option to create a new channel. Choose 'Messaging API' as the channel type. You will need to provide details such as the channel name, description, and category. This channel represents your application or bot that interacts with Line users Line channel creation guide.
4. Obtain Channel Credentials: After creating your Messaging API channel, navigate to its settings within the Line Developers Console. You will find two critical credentials under the 'Basic settings' or 'Channel settings' tab:
   • Channel ID: A unique identifier for your channel.
   • Channel Secret: A secret key used to verify the authenticity of requests from the Line platform to your webhook endpoint.
   • Channel Access Token: This token is required to authenticate your API requests when sending messages or interacting with the Line API. You can issue a new long-lived channel access token from the Messaging API tab of your channel settings.

These credentials (Channel ID, Channel Secret, and Channel Access Token) are essential for making authenticated requests to the Line Messaging API. Store them securely and avoid hardcoding them directly into your application code, especially in production environments.

Your first request

Once you have obtained your channel access token, you can make your first API request to send a message. This example demonstrates sending a simple text message using a curl command. For more complex applications, using one of Line's official SDKs is recommended Line SDKs documentation.

Prerequisites

• A Line Developers account with a Messaging API channel.
• A valid Channel Access Token.
• The User ID of a Line user to whom you want to send a message. You can find your own User ID by adding your bot as a friend and sending it a message; the User ID will appear in the webhook event logs, or you can use the Line Developers Console's 'Trial Message' feature.

Sending a Push Message with curl

The following curl command sends a push message to a specified user. Replace <YOUR_CHANNEL_ACCESS_TOKEN> and <USER_ID> with your actual credentials and the recipient's User ID.

curl -v -X POST https://api.line.me/v2/bot/message/push \
-H 'Content-Type: application/json' \
-H 'Authorization: Bearer <YOUR_CHANNEL_ACCESS_TOKEN>' \
-d '{ "to": "<USER_ID>", "messages": [ { "type": "text", "text": "Hello from Line Messaging API!" } ] }'

This command sends a JSON payload to the /v2/bot/message/push endpoint. The to field specifies the recipient's User ID, and the messages array contains the message content. In this case, it's a simple text message.

Using an SDK (Node.js Example)

Line provides SDKs for several programming languages, simplifying API interactions. Here's an example using the Node.js SDK to send the same push message:

const line = require('@line/bot-sdk');

const client = new line.Client({
  channelAccessToken: '<YOUR_CHANNEL_ACCESS_TOKEN>'
});

const message = {
  type: 'text',
  text: 'Hello from Line Messaging API!'
};

const userId = '<USER_ID>';

client.pushMessage(userId, message)
  .then(() => {
    console.log('Message sent successfully!');
  })
  .catch((err) => {
    console.error(err);
  });

First, install the Node.js SDK: npm install @line/bot-sdk. Then, replace <YOUR_CHANNEL_ACCESS_TOKEN> and <USER_ID> with your values. This code initializes the Line client with your access token and then uses the pushMessage method to send the text message.

Common next steps

After successfully sending your first message, consider these common next steps to further develop your Line application:

• Set up a Webhook: To receive messages and events from Line users, you need to configure a webhook endpoint for your channel. This endpoint will receive JSON payloads from Line whenever an event occurs (e.g., a user sends a message, adds your bot as a friend). You can set up your webhook URL in the Line Developers Console under your channel's Messaging API settings. This is crucial for building interactive chatbots that can respond to user input.
• Explore Message Types: Line supports a variety of rich message types beyond simple text, including stickers, images, videos, audio, location, and interactive templates like Flex Messages. Experiment with these to create more engaging user experiences. The Line Messaging API reference provides details on all available message objects.
• Implement Reply Messages: Instead of push messages, which can be sent anytime, reply messages are sent in response to a user's action within a limited time frame (typically within 5 minutes of receiving an event). Reply messages are free and essential for conversational bots. The Line documentation on reply messages offers guidance.
• Integrate with Line Login: For applications that require user identity or profile information, integrate Line Login. This allows users to log in to your service using their Line account, providing access to their display name, profile picture, and other public information, subject to user consent.
• Explore the Free Plan Limitations: Understand the Line Messaging API Free Plan, which allows up to 1,000 push messages per month and unlimited reply messages. As your application scales, you may need to consider a paid plan.
• Secure Your Webhook: If you set up a webhook, ensure its security. Verify the signature of incoming requests from Line to confirm their authenticity. This prevents malicious actors from sending forged events to your endpoint. The Line documentation on signature verification provides necessary steps. For general webhook security, resources like AWS API Gateway webhook security best practices can also offer relevant insights.

Troubleshooting the first call

If your first API call to Line's Messaging API fails, consider the following common issues and troubleshooting steps:

• Invalid Channel Access Token: This is a frequent cause of authentication errors. Double-check that your Channel Access Token is correct, has not expired, and is included in the Authorization: Bearer header of your request. Ensure there are no extra spaces or characters. You can re-issue a new token from the Line Developers Console if needed.
• Incorrect User ID: Ensure the to field in your request contains a valid User ID of a Line user who has added your bot as a friend. If the user has not added your bot, they will not receive push messages. Test with your own User ID first.
• JSON Payload Errors: Verify that your JSON payload is correctly formatted. Even minor syntax errors (missing commas, unclosed braces, incorrect data types) can cause the API to reject the request. Use a JSON linter to check your payload.
• HTTP Status Codes: Pay attention to the HTTP status code returned in the API response. Common codes include:
  • 200 OK: Success.
  • 400 Bad Request: Indicates issues with your request payload or parameters.
  • 401 Unauthorized: Typically an issue with your Channel Access Token.
  • 403 Forbidden: May indicate insufficient permissions or an expired token.
  • 404 Not Found: Incorrect API endpoint URL.
  • 5xx Server Error: An issue on Line's side.
• API Rate Limits: While less likely for a first call, be aware that Line has rate limits. If you send too many requests in a short period, subsequent requests might be temporarily blocked Line API rate limit documentation.
• Network Issues: Ensure your development environment has a stable internet connection and is not being blocked by a firewall from reaching Line's API endpoints (api.line.me).
• Check Line Developers Console Logs: The Line Developers Console may provide some logging or error messages related to your channel's activity, especially if you have configured a webhook. Review these logs for insights into failed requests or events.