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
Build
- Read references/guidelines.md first (policy rules, specs, constraints)
- Load the relevant reference for the feature being implemented
- For architecture or design choices, consult references/experts.md for directional guidance
- Write code following specs and constraints from references
Review / Debug
- Read references/guidelines.md (policy rules, specs, constraints)
- Load relevant references for the code being reviewed
- Cross-check code against specs (token lifecycle, message limits, scope requirements, template naming, IAP order flow)
- For design pattern concerns, consult references/experts.md
- Report violations with reference to specific constraints
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.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 was terminated in Japan on April 30, 2025 — no longer available for JP MINI Apps. Still available in Taiwan / Thailand; verify region-specific 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
1---2name: line-mini-app3description: Builds, submits, and operates LINE MINI App — Service Messages (notification token), Common Profile Quick Fill, In-App Purchase (JP), Console setup (3 internal channels), Custom Path, channel consent simplification, custom share messages, submission review, and verified vs unverified MINI App rules. Use when the user mentions LINE MINI App, mini app, service message, notification token, Common Profile, Quick Fill, in-app purchase, IAP, MINI App review, MINI App Console, or LIFF features that only apply to MINI Apps.4---56# LINE MINI App78**Do not answer LINE MINI App questions from memory — LINE updates APIs frequently and training data is unreliable. Always consult the references below.**910LINE MINI App is a web app platform built on LIFF that runs inside LINE.1112## Workflow1314### Build151. Read [references/guidelines.md](references/guidelines.md) first (policy rules, specs, constraints)162. Load the relevant reference for the feature being implemented173. For architecture or design choices, consult [references/experts.md](references/experts.md) for directional guidance184. Write code following specs and constraints from references1920### Review / Debug211. Read [references/guidelines.md](references/guidelines.md) (policy rules, specs, constraints)222. Load relevant references for the code being reviewed233. Cross-check code against specs (token lifecycle, message limits, scope requirements, template naming, IAP order flow)244. For design pattern concerns, consult [references/experts.md](references/experts.md)255. Report violations with reference to specific constraints2627## Environment Variables2829```30LIFF_ID=LIFF app ID (LINE MINI App runs on LIFF)31LINE_CHANNEL_ACCESS_TOKEN=Stateless channel access token (Service Messages, IAP)32LINE_LOGIN_CHANNEL_ID=LINE Login Channel ID (server-side verification)33LINE_LOGIN_CHANNEL_SECRET=Channel secret (server-side only)34```3536## MINI App vs LIFF3738| Feature | LIFF | MINI App |39|---------|------|----------|40| Service Messages | ✗ | ✅ Proactive notifications via notification token |41| Common Profile Quick Fill | ✗ | ✅ Auto-fill forms with LINE profile data |42| In-App Purchase | ✗ | ✅ App store payments (iOS/Android) |43| Submission review | Not required | Required (LINE review process) |44| Entry point | LIFF URL | LINE MINI App list + LIFF URL |4546All LIFF APIs are available in MINI App context (LIFF browser). See Key Constraints for external browser limitations.4748## Service Messages4950```51User opens MINI App → liff.getAccessToken() → Issue notification token → Send service messages (max 5)52```5354- Token validity: **1 year**, max **5 messages** per token55- LIFF access token is **revoked when user closes the MINI App** — issue notification token before user leaves5657Full API specs, template structure, error codes → **[references/service-messages.md](references/service-messages.md)**5859## Common Profile Quick Fill6061```javascript62const result = await liff.$commonProfile.get(scopes, { formatOptions });63liff.$commonProfile.fill(result.data); // auto-fill <input data-liff-autocomplete="...">64```6566Full API specs, scopes, dummy data → **[references/common-profile.md](references/common-profile.md)**6768## In-App Purchase6970Japan only. Consumable digital content only. Requires LIFF SDK ≥ 2.26.0, LINE ≥ 15.6.0, LIFF browser.7172Purchase flow (client + server), dev guidelines, error codes → **[references/in-app-purchase.md](references/in-app-purchase.md)**7374## Key Constraints7576- MINI App runs on LIFF — all LIFF constraints apply (Endpoint URL, init order, environment differences)77- Stateless channel access tokens only — long-lived and v2.1 tokens **cannot be used** for MINI App channels78- Channel consent simplification only skips `openid` — `profile`, `email`, `chat_message.write` require verification screen; needs LIFF SDK **v2.13.x+**, verified MINI App79- Custom share messages must use **Bubble** container (not Carousel); actions only on buttons and footer80- External browser: `liff.init()` doesn't auto-login (use `withLoginOnExternalBrowser: true`); `sendMessages`, `openWindow`, `closeWindow`, `iap.*` unavailable81- LINE Pay was terminated in Japan on April 30, 2025 — no longer available for JP MINI Apps. Still available in Taiwan / Thailand; verify region-specific availability at [LINE Pay docs](https://developers.line.biz/en/docs/line-mini-app/develop/iap/)82- IAP auth differs by endpoint: reserve uses **user** token, webhook history uses **channel** token; webhook uses **signature verification**, not IP restriction83- Channel **cannot be moved** to another provider after creation; user IDs differ per provider8485## Reference Index8687| File | Topic |88|------|-------|89| [references/guidelines.md](references/guidelines.md) | **Read first.** MINI App overview, verified vs unverified, specs, performance, migration, development rules, Quick Fill design regulations |90| [references/console-setup.md](references/console-setup.md) | Channel creation, 3 internal channels, LIFF ID, tokens, basic auth, display mapping, localization, settings reflection, re-review |91| [references/features.md](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 |92| [references/service-messages.md](references/service-messages.md) | Notification token lifecycle, sending API, template structure, review lifecycle, character limits, error codes |93| [references/common-profile.md](references/common-profile.md) | Quick Fill API, scopes, form auto-fill, plugin setup, dummy data |94| [references/in-app-purchase.md](references/in-app-purchase.md) | Purchase flow (client + server), reserve, webhooks, dev guidelines, application & setup, test payment, error codes |95| [references/submission-review.md](references/submission-review.md) | Submission process, pre-review checklist, review period, approval flow, publish changes |96| [references/experts.md](references/experts.md) | LINE MINI App domain experts for architecture guidance |9798## SDK & Tools99100- LINE MINI App is built on **LIFF SDK**: [@line/liff](https://www.npmjs.com/package/@line/liff)101- **Quick Fill plugin**: [@line/liff-common-profile-plugin](https://www.npmjs.com/package/@line/liff-common-profile-plugin)102- Scaffold: `npx @line/create-liff-app`103- **LINE MINI App Playground**: [miniapp.line.me/lineminiapp_playground](https://miniapp.line.me/lineminiapp_playground) — online MINI App API testing
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