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
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.writerequire 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 (usewithLoginOnExternalBrowser: 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