| name | line-mini-app |
| description | LINE MINI App official documentation at API-reference depth. Covers the complete LINE MINI App platform: building a web app that runs inside the LINE app as a LIFF app, the LINE MINI App channel and its three internal channels (Developing / Review / Published), the verification review that turns an unverified MINI App into a verified MINI App, and every LINE MINI App API. Use this skill whenever the task touches LINE MINI App: creating a LINE MINI App channel, configuring it in the LINE Developers Console, the built-in action button / dropdown menu / multi-tab view, implementing a custom action button with Flex Message share messages and the share target picker, sending service messages, Channel consent simplification and the authorization flow, Common Profile Quick-fill, in-app purchase (IAP), Custom Path, permanent links, adding a shortcut to the home screen, opening a LINE MINI App in an external browser, handling payments (LINE Pay / IAP), the verified-badge review and submission flow, or placing ads. Covers every LINE MINI App API endpoint and method: the Service Message API (issue a service notification token at message/v3/notifier/token, send a service message at message/v3/notifier/send), the Common Profile Quick-fill LIFF plugin (liff.$commonProfile.get / getDummy / fill, LiffCommonProfilePlugin, @line/liff-common-profile-plugin), and in-app purchase (liff.iap. getPlatformProducts / requestConsentAgreement / createPayment, the Reserve purchase endpoint iap/v1/product/reserve, the Get webhook event history endpoint iap/v1/webhook/events, the purchaseComplete and refundComplete webhook events). Trigger on mentions of: LINE MINI App, miniapp.line.me, LIFF ID, LIFF URL, liff.line.me, developers.line.biz/docs/line-mini-app, developers.line.biz/reference/line-mini-app, service notification token, notificationToken, service message template, channel consent simplification, Quick-fill, $commonProfile, liff.iap, productId, orderId, in-app purchase, verified MINI App, unverified MINI App, LINE Developers Console MINI App channel, custom action button, permanent link of a LINE MINI App, createShortcutOnHomeScreen, LY Corporation verification review. |
LINE MINI App Reference
API-reference-level coverage of the LINE MINI App platform, extracted from the
official documentation at https://developers.line.biz/en/docs/line-mini-app/
and the API reference at https://developers.line.biz/en/reference/line-mini-app/.
A LINE MINI App is a web application that runs inside the LINE app. It is a
LIFF app added to a
LINE MINI App channel, with LINE-MINI-App-specific requirements, restrictions,
and APIs layered on top. Most of the front-end runtime is the plain LIFF SDK —
this skill covers only the parts that are specific to LINE MINI App. For the
generic LIFF API (liff.init(), liff.getProfile(), liff.sendMessages(),
liff.getAccessToken(), etc.) consult LIFF documentation.
The docs are split here into topic-scoped reference files. Read the reference
file that matches the task — do not guess endpoint paths, method signatures,
scope names, or JSON shapes.
When this skill applies
Any work on a LINE MINI App: creating and configuring the channel, developing
the LIFF app under LINE MINI App rules, the built-in action button, sharing
pages with custom Flex Message share messages, sending service messages,
Channel consent simplification, Common Profile Quick-fill, in-app purchase,
Custom Path, permanent links, home-screen shortcuts, external-browser support,
payments, the verification review, ads. Works for raw HTTP calls (curl,
fetch, axios, requests) for the server-side APIs and for the LIFF SDK +
LIFF plugins on the client side.
Core mental model
| Concept | What it means |
|---|
| LINE MINI App = LIFF app | Built with the LIFF SDK (min v2.1). LINE MINI App adds requirements/restrictions and three extra APIs (Service Message, Quick-fill, IAP). |
| LINE MINI App channel | One channel per LINE MINI App, created in the LINE Developers Console. Internally it is three channels: Developing, Review, Published — each with its own LIFF ID and Endpoint URL. |
| Unverified vs verified | New channels are unverified MINI Apps. Passing LY Corporation's verification review makes them verified MINI Apps and unlocks features (service messages, Custom Path, Quick-fill, home-screen shortcut, channel consent simplification, verified badge). |
| LIFF URL | https://miniapp.line.me/{liffId} (since 2023-12-13; old https://liff.line.me/{liffId} still opens). Each internal channel has a distinct LIFF ID. |
| Permanent link | LIFF URL + (page URL − Endpoint URL) — used to share/deep-link a specific LINE MINI App page. |
| Channel access token | LINE MINI App channels can use only stateless tokens or short-lived tokens — never long-lived or v2.1. Stateless is recommended. |
Reference file map
| File | Contents |
|---|
references/overview-and-console.md | What a LINE MINI App is, built-in features (action button / dropdown menu / multi-tab view), custom features, UI components (header / body), the three internal channels, LINE Developers Console guide, creating a LINE MINI App channel, channel-setting → user-facing-screen mapping, LINE MINI App vs native apps, quickstart, web-app-to-MINI-App migration |
references/develop.md | Develop overview, specifications & supported environment, development guidelines (mass-request ban, log saving, deauthorization), Channel consent simplification & the authorization flow, Custom Path, permanent links, add shortcut to home screen, opening in an external browser, handling payments (LINE Pay / IAP), performance guidelines, basic authentication |
references/custom-action-button-and-flex.md | Implementing a custom action button, the share target picker, the standard-type and image-list-type custom share message Flex Message structures with full component property tables, and the two complete example JSON files |
references/service-messages.md | Service messages concept, flow, templates, character limits — plus the Service Message API reference: Issue a service notification token, Send a service message (request headers/body, response, errors, examples) |
references/quick-fill.md | Common Profile Quick-fill overview, the LIFF plugin (LiffCommonProfilePlugin, @line/liff-common-profile-plugin), scopes & return values, dummy data, design regulations & Auto-fill button rules — plus the client API reference: liff.$commonProfile.get() / getDummy() / fill() |
references/in-app-purchase.md | In-app purchase overview, conditions, IAP development guidelines, applying & setting up IAP, the full implementation flow and test payments — plus the IAP API reference: client methods (liff.iap.getPlatformProducts/requestConsentAgreement/createPayment), server endpoints (Reserve purchase, Get webhook event history), webhook events (purchaseComplete, refundComplete), the product ID list |
references/submit-service-and-demos.md | Submitting a LINE MINI App for verification review, the review process and status flow, re-review after updating a verified MINI App, running your service, conditions for service messages, ads, using a LINE Official Account, design specs (icon, safe area, loading icon), demo apps and technical case studies |
Quick API index
LINE MINI App has three distinct API surfaces. The generic LIFF API is separate.
SERVICE MESSAGE API (server-side; verified MINI Apps only)
POST https://api.line.me/message/v3/notifier/token Issue a service notification token
POST https://api.line.me/message/v3/notifier/send?target=service Send a service message
COMMON PROFILE QUICK-FILL (client-side LIFF plugin; verified MINI Apps only)
liff.$commonProfile.get(scopes, options) Get the user's Common Profile (shows confirm modal)
liff.$commonProfile.getDummy(scopes, options, caseId) Get dummy Common Profile data (caseId 1-10)
liff.$commonProfile.fill(profile) Auto-fill a <form> via data-liff-autocomplete attrs
IN-APP PURCHASE — client (LIFF SDK; verified MINI Apps, Japan only)
liff.iap.getPlatformProducts({ productIds }) Get localized price/currency/name for product IDs
liff.iap.requestConsentAgreement() Request consent to the LINE IAP Terms of Use
liff.iap.createPayment({ productId, orderId }) Launch the App Store / Google Play payment sheet
IN-APP PURCHASE — server (verified MINI Apps, Japan only)
POST https://api.line.me/iap/v1/product/reserve Reserve a purchase → returns orderId
GET https://api.line.me/iap/v1/webhook/events Get webhook event history (cursor pagination)
IN-APP PURCHASE — webhook events delivered to your server
purchaseComplete Payment settled by LY Corporation — grant the item
refundComplete A purchase was refunded
Working rules
- A LINE MINI App channel is three channels. Always issue a separate channel
access token, set a separate Endpoint URL, and pass the matching LIFF ID to
liff.init() for each of Developing / Review / Published. Mixing them is the
most common failure.
- Verified-only features. Service messages, Custom Path, Quick-fill,
home-screen shortcut (
liff.createShortcutOnHomeScreen()), and Channel
consent simplification require a verified MINI App. Unverified MINI Apps can
only test these on the internal channels for Developing and Review.
- Token types. LINE MINI App channels cannot use long-lived or v2.1 channel
access tokens — use stateless (recommended, unlimited issuance, 15 min) or
short-lived (30 days) tokens.
- Service notification token. Issued from a LIFF access token; one per LIFF
access token; valid 1 year; lets you send up to 5 service messages for one
user action. Every send returns a renewed token in the response — save it
for the next message in the sequence.
- Service messages are confirmation/response only. No ads, promotions,
coupons, or event notices — violating this gets the API suspended.
- IAP: grant items only on the
purchaseComplete webhook. A successful
Reserve purchase does not guarantee payment. Dedupe by orderId (webhooks
may arrive multiple times) and verify the x-line-signature (HMAC-SHA256 of
the raw body keyed by the channel secret).
- External browser. Since Oct 2025 LINE MINI Apps also run in external
browsers.
liff.init() does not auto-login there — use
withLoginOnExternalBrowser: true or call liff.login() explicitly.
liff.sendMessages(), liff.openWindow(), liff.closeWindow(), and
liff.iap.* do not work in an external browser.
- Custom share messages must be a single Flex
bubble (never a carousel)
and must follow the exact component structure in the guidelines.
- Save logs of Service Message API requests yourself — LY Corporation does not
provide them.
