LINE MINI App Service Message Template Review: A Pre-Submission Checklist
Before submitting a LINE MINI App service message template for review, choose one of LINE’s provided templates, describe the exact user action and notification sequence in Use Case, test every variable and permanent link, and remove promotional content. Production sending requires a verified MINI App and a template whose Published status is PUBLISHING; a simulator test or DEVELOPING status is not production approval.
Key takeaways
- Service messages must confirm or respond to an action the user completed in the MINI App. Discounts, rewards, new-product notices, coupons, promotions, and general event announcements are prohibited.
- LINE provides the template layouts; teams select a suitable category and language, supply approved variable values and links, and explain the real use case.
- A channel can add up to 20 service message templates. The API name follows
{template name}_{BCP 47 language tag}and must match LINE Developers Console. - While the MINI App channel is under review, teams can inspect templates and use the simulator, but cannot add, edit, or delete templates.
- Editing service message template information after verification requires re-review, so treat the reviewed use case as a production contract.
What the LINE service message template review approves
LINE’s service message guide separates three things that are easy to confuse:
- MINI App eligibility: production service messages are available only to verified LINE MINI Apps. An unverified app can test on its internal Developing channel with Admin or Tester accounts.
- Template review: the selected template and its stated use case must pass LY Corporation’s review before production use.
- Runtime authorization: after approval, the server still needs a service notification token tied to the user and action before it can call the send API.
The verified-versus-unverified guide covers eligibility; the notification token tutorial covers runtime authorization. This checklist covers template preparation.
| Review state | What you can do | What it does not prove |
|---|---|---|
DEVELOPING | Preview and test with eligible developer accounts on the internal Developing channel | That production users can receive the message |
| MINI App channel under review | View template details and send simulator tests | Permission to add, edit, or delete templates during the review |
PUBLISHING | Use the reviewed template from the production channel after the MINI App is verified | Permission to change the use case or turn the template into a promotion |
| Template edited after verification | Prepare the updated configuration for re-review | That the previous approval automatically covers the change |
LINE MINI App service message template review checklist
1. Start with one user action, not the message copy
Write the triggering action first: a reservation, queue registration, order, check-in, shipment request, or another action completed in the MINI App. Then list the confirmation, result, or reminder caused by that action. LINE permits up to five service messages per action, although the reviewed limit can vary by use case.
2. Choose the closest provided template and language
LINE supplies templates by categories such as store reservations, queue management, and delivery notifications. The available service-message languages are Japanese, English, Traditional Chinese, Thai, Indonesian, and Korean. Select the layout that matches the operation; do not force promotional copy into a transactional template.
Record the exact Template name for API use shown in the console. The request field is templateName, and the value uses the format {template name}_{BCP 47 language tag}. A visually similar label or a hand-built suffix is not a safe substitute.
3. Make the Use Case specific enough to test
The Use Case field should say who performs the action, where it happens, what each notification confirms, and when each notification is sent. Avoid a vague description such as “customer updates.” A reviewable version is closer to: “A user completes a delivery booking in the MINI App; send booking confirmation immediately and a delivery-status result when the carrier updates the order.”
LINE warns that deviating from the submitted Use Case can disable the template. Keep the approved description beside the job definition so later changes do not quietly expand its scope.
4. Validate variables, character limits, and permanent links
Use the console preview to exercise short, typical, and maximum-length values for every variable. Confirm that dates, names, order references, and localized strings fit both the recommended and hard limits of the selected template. If the template has no variables, the send request still needs params: {}.
Buttons must use permanent links to LINE MINI App pages. The first button is required; additional buttons depend on the template. Test destinations inside LINE, including authentication and expired-order states.
5. Run simulator tests before freezing the review set
The console can send a test message to the LINE account linked to the currently signed-in developer account. Use that path to verify layout, variable ordering, locale, button behavior, and the footer. A simulator success proves rendering, not production eligibility.
Complete the template set before submitting the channel. During review you cannot add a template, edit Use Case, or delete one; finding a missing notification then delays release.
6. Define the post-approval change boundary
After the MINI App is verified, changes to any service message template information require re-review under LINE’s update guidance. Route template edits through change control: compare the new user action, content, variables, links, and timing with the approved version before releasing code that depends on them.
At runtime, record templateName, the action or order ID, sessionId, and remainingCount, but keep all tokens out of logs. Approval does not replace token lifecycle handling.
Where UnifyPort fits
UnifyPort does not submit or approve LINE MINI App templates, change a template’s Published status, issue LINE service notification tokens, or extend LINE’s allowed content. Use the official LINE MINI App flow whenever the notification belongs to a reservation, order, queue, or other action inside the MINI App.
UnifyPort addresses a separate requirement: receiving free-form customer messages from a connected ordinary LINE account. LINE account authorization uses a QR flow, and supported inbound messages arrive as the standard message.received event. When the webhook endpoint has a signing_secret, delivery includes X-Device-Timestamp and X-Device-Signature for HMAC-SHA256 verification.
That separation matters if a user receives an official service message and then asks a support question. The reviewed template owns the transactional notification; a separate inbound message path can own the conversation. The LINE inbound guide explains that second architecture without claiming to change MINI App eligibility.
Limitations and trade-offs
- The official LINE flow is the correct choice when the MINI App must send approved transactional notifications. An unofficial interface cannot grant verified status or template approval.
- A
PUBLISHINGtemplate is not a general messaging permission. Content must remain within the reviewed use case and service-message policy. - Template approval does not guarantee that every API call succeeds. Tokens expire or rotate, remaining counts reach zero, and invalid variables can still fail at runtime.
- Service messages are not a customer-support inbox. Design a separate intake path if users need to ask open-ended questions.
FAQ
What status means a LINE service message template passed review?
LINE documents PUBLISHING as the Published status for a template that passed review and can be used with the production channel after the MINI App is verified.
Can an unverified LINE MINI App request production service messages?
No. An unverified MINI App can test service messages on its internal Developing channel with eligible developer accounts, but production sending requires a verified MINI App and a reviewed template.
Can a service message include a coupon or promotion?
No. LINE prohibits discounts, shopping rewards, new-product information, coupons, promotions, advertisements, and general event notices. The message must confirm or respond to a user action in the MINI App.
Can I edit a template while the MINI App channel is under review?
No. During review, you can inspect template details and use the simulator, but you cannot add a template, edit its Use Case, or delete it. Prepare the complete set before submitting.
Does changing a service message template require re-review?
Yes. LINE lists all service message template information among the LINE Developers Console settings that require re-review after a verified MINI App is updated.
Next step
Use the official LINE service message guide to prepare the template, Use Case, variables, and simulator evidence before review. If your actual requirement is free-form customer-message intake instead of a transactional MINI App notification, follow the UnifyPort LINE authorization guide as the separate implementation path.
Sources
Official LINE sources checked on July 28, 2026: