line-mini-app

Original：🇺🇸 English

Translated

Comprehensive reference for LINE MINI App — Service Messages, Common Profile Quick Fill, In-App Purchase, Console setup (3 internal channels), submission review, and performance guidelines for web apps running inside LINE as an enhanced LIFF platform. This skill should be used when the user asks to "build a LINE MINI App", "send a service message", "set up Common Profile Quick Fill", "implement in-app purchase", "configure MINI App Console", "submit MINI App for review", or mentions LINE MINI App, Service Messages, notification token, Common Profile, IAP purchase flow, 3 internal channels, consent simplification, Custom Path, custom share messages, or verified vs unverified MINI App. Always use this skill whenever the user mentions LINE MINI App, mini apps in LINE, or enhanced LIFF features like service messages or in-app purchase, even if they don't explicitly say "MINI App".

1installs

Sourceabgne/line-dev

Added on2026-04-04

NPX Install

npx skill4agent add abgne/line-dev line-mini-app

SKILL.md Content

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LINE MINI App

Do not answer LINE MINI App questions from memory — LINE updates APIs frequently and training data is unreliable. Always consult the references below.

LINE MINI App is a web app platform built on LIFF that runs inside LINE.

Workflow

Read references/guidelines.md first (policy rules, specs, constraints)
Load the relevant reference for the feature being worked on
For architecture or design choices, consult references/experts.md
When reviewing, cross-check code against specs (token lifecycle, message limits, scope requirements, template naming, IAP order flow)

Environment Variables

LIFF_ID=LIFF app ID (LINE MINI App runs on LIFF)
LINE_CHANNEL_ACCESS_TOKEN=Stateless channel access token (Service Messages, IAP)
LINE_LOGIN_CHANNEL_ID=LINE Login Channel ID (server-side verification)
LINE_LOGIN_CHANNEL_SECRET=Channel secret (server-side only)

MINI App vs LIFF

Feature	LIFF	MINI App
Service Messages	✗	✅ Proactive notifications via notification token
Common Profile Quick Fill	✗	✅ Auto-fill forms with LINE profile data
In-App Purchase	✗	✅ App store payments (iOS/Android)
Submission review	Not required	Required (LINE review process)
Entry point	LIFF URL	LINE MINI App list + LIFF URL

All LIFF APIs are available in MINI App context (LIFF browser). See Key Constraints for external browser limitations.

Service Messages

User opens MINI App → liff.getAccessToken() → Issue notification token → Send service messages (max 5)

Token validity: 1 year, max 5 messages per token
LIFF access token is revoked when user closes the MINI App — issue notification token before user leaves

Full API specs, template structure, error codes → references/service-messages.md

Common Profile Quick Fill

javascript

const result = await liff.$commonProfile.get(scopes, { formatOptions });
liff.$commonProfile.fill(result.data);  // auto-fill <input data-liff-autocomplete="...">

Full API specs, scopes, dummy data → references/common-profile.md

In-App Purchase

Japan only. Consumable digital content only. Requires LIFF SDK ≥ 2.26.0, LINE ≥ 15.6.0, LIFF browser.

Purchase flow (client + server), dev guidelines, error codes → references/in-app-purchase.md

Key Constraints

MINI App runs on LIFF — all LIFF constraints apply (Endpoint URL, init order, environment differences)
Stateless channel access tokens only — long-lived and v2.1 tokens cannot be used for MINI App channels
Channel consent simplification only skips
```
openid
```
—
```
profile
```
,
```
email
```
,
```
chat_message.write
```
require verification screen; needs LIFF SDK v2.13.x+, verified MINI App
Custom share messages must use Bubble container (not Carousel); actions only on buttons and footer

External browser:

liff.init()

doesn't auto-login (use

withLoginOnExternalBrowser: true

);

sendMessages

,

openWindow

,

closeWindow

,

iap.*

unavailable

LINE Pay terminated in Japan (April 30, 2025) — verify current availability at LINE Pay docs
IAP auth differs by endpoint: reserve uses user token, webhook history uses channel token; webhook uses signature verification, not IP restriction
Channel cannot be moved to another provider after creation; user IDs differ per provider

Reference Index

File	Topic
references/guidelines.md	Read first. MINI App overview, verified vs unverified, specs, performance, migration, development rules, Quick Fill design regulations
references/console-setup.md	Channel creation, 3 internal channels, LIFF ID, tokens, basic auth, display mapping, localization, settings reflection, re-review
references/features.md	Built-in features (action button, multi-tab, consent simplification), custom features (Custom Path, shortcuts, custom action button, share messages, OA, payments), permanent links, external browser, UI components
references/service-messages.md	Notification token lifecycle, sending API, template structure, review lifecycle, character limits, error codes
references/common-profile.md	Quick Fill API, scopes, form auto-fill, plugin setup, dummy data
references/in-app-purchase.md	Purchase flow (client + server), reserve, webhooks, dev guidelines, application & setup, test payment, error codes
references/submission-review.md	Submission process, pre-review checklist, review period, approval flow, publish changes
references/experts.md	LINE MINI App domain experts for architecture guidance

SDK & Tools

LINE MINI App is built on LIFF SDK: @line/liff
Quick Fill plugin: @line/liff-common-profile-plugin
Scaffold:
```
npx @line/create-liff-app
```
LINE MINI App Playground: miniapp.line.me/lineminiapp_playground — online MINI App API testing