LINE LIFF API Reference

Overview

This skill provides a structured reference for integrating and interacting with the LINE Front-end Framework (LIFF) client-side JS SDK. It covers LIFF SDK properties, initialization, authentication, user context, profile retrieval, and custom features like share target picker and scanning codes.

When to Use

• Building web applications that run inside LINE's in-app LIFF browser or external browsers.
• Initializing the LIFF SDK using liff.init() to gain access to LINE features.
• Performing user authentication (liff.login(), liff.logout(), liff.isLoggedIn()).
• Fetching user details (liff.getProfile(), liff.getDecodedIDToken()).
• Sending messages directly to the current chat room (liff.sendMessages()) or selecting target friends to share content (liff.shareTargetPicker()).
• Getting runtime environment parameters (OS, language, LINE version, etc.).

Core Pattern

Always call liff.init() as early as possible and wait for the returned promise to resolve before calling other LIFF SDK methods.

Initialization & Login Flow (JavaScript)

import liff from '@line/liff';