> ## Documentation Index
> Fetch the complete documentation index at: https://koreai.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.
# Set up LINE
[Back to messaging or digital channels](/agent-platform/channels#messaging-or-digital)
Connect a LINE Official Account to your agent so people reach it in LINE for chat and media messaging. You create the Official Account, enable the Messaging API on it, collect two credentials and one identifier, then register a webhook and verify it before any real traffic arrives.
The setup requires:
1. [LINE setup](#line-setup): Create the Official Account, enable the Messaging API, and collect the Channel Secret, Channel Access Token, and Destination ID.
2. [Artemis channel configuration](#artemis-channel-configuration) using those three values, then copy the generated webhook URL.
3. [Webhook configuration in LINE](#webhook-configuration-in-line): Register the webhook URL, verify it, and switch delivery on.
After the configuration is complete, LINE posts every event for the channel to Artemis, which resolves the connection from the payload and hands the message to the deployed agent.
**Important considerations**
* **Two consoles, two halves of the job**: LINE splits the work between LINE Official Account Manager and the LINE Developers Console. Sign in to both with the same account, because the Developers Console asks first-time users to register a developer profile with a name and email, and an account that skips that step can't see the channel it just created.
* **Official Account Manager creates the channel, not the Developers Console**: LINE removed the ability to create Messaging API channels directly in the Developers Console in September 2024. Enabling the Messaging API on the Official Account creates the channel.
* **Provider selection is permanent**: You can't change or remove the provider afterwards, and a person receives a different user ID under each provider, so moving an account later would break every stored user reference.
* **The Destination ID is not shown in either console**: It comes from an API call. Three identifiers that are shown look plausible and none of them route. See [How Artemis routes LINE events](#how-artemis-routes-line-events).
| Console | What you do there |
| --------------------------------------------------------------- | ----------------------------------------------------------------------------------------------- |
| [LINE Official Account Manager](https://manager.line.biz/) | Create the Official Account, enable the Messaging API, and turn off LINE's automatic replies. |
| [LINE Developers Console](https://developers.line.biz/console/) | Copy the Channel Secret and access token, set the webhook URL, and find the friend-add QR code. |
## Prerequisites
* A LINE Business ID, registered with an existing personal LINE account or with an email address. See [LINE setup](#line-setup).
* The admin role on the Official Account and on the Messaging API channel. Several steps hide their controls from lower roles rather than reporting a permission error.
* The admin role on the provider you intend to use, if you plan to select an existing one. A provider only appears in the selection list when your account holds that role on it.
* Artemis project access with permission to open **Deployments** -> **Channels**, and a deployed agent in the environment you intend to bind.
***
## How Artemis routes LINE events
LINE sends every event for a channel to one URL, so Artemis identifies the connection from the payload rather than the path. Each webhook body carries a `destination` field holding the bot's user ID, and Artemis resolves the connection from that value before it verifies the signature.
| Piece | Who owns it | What it does |
| ------------------------ | ----------- | ----------------------------------------------------------------------------------------------------------------------------- |
| **Destination ID** | LINE | Routes inbound events. It has to be the bot's user ID, which begins with `U`. |
| **Channel Secret** | LINE | Verifies the `X-Line-Signature` header. Artemis computes HMAC-SHA256 over the unchanged request body and compares the result. |
| **Channel Access Token** | LINE | Authorizes outbound calls: replies, push messages, bot info lookups, and the loading indicator. |
| **Webhook URL** | Artemis | Receives events. The route carries no Destination ID, because the destination travels in the signed body. |
Three LINE identifiers look plausible in the Destination ID field and none of them route. The **Channel ID** on the Basic settings tab is numeric. The **Bot basic ID** on the Messaging API tab starts with `@`. **Your user ID**, also on the Basic settings tab, is your own personal LINE account, not the bot's. The correct value comes from an API call, covered in [LINE setup](#line-setup).
***
## LINE setup
Complete all of this in LINE before you open Artemis. Start at the beginning even if someone has already created an Official Account, because enabling the Messaging API is what creates the channel you'll configure.
LINE accounts for business sit behind a Business ID, which you can register with an existing personal LINE account or with an email address.
1. Go to [account.line.biz](https://account.line.biz/signup?redirectUri=https://entry.line.biz/form/entry/unverified) and register a Business ID, if your organization doesn't already have one.
2. Use an account your team can keep. This identity carries the admin role for everything that follows.
1. Complete LINE's [Official Account entry form](https://entry.line.biz/form/entry/unverified) with your business details. Submitting it creates the account.
2. Open [LINE Official Account Manager](https://manager.line.biz/) and confirm the new account appears in your list before you continue.
1. In Official Account Manager, select the account.
2. Go to **Settings** -> **Messaging API** and enable the Messaging API. This is what creates the channel that Artemis connects to.
You can't do this anywhere else. LINE removed the ability to create Messaging API channels directly in the Developers Console in September 2024, so an attempt to start from the developer side has nothing to create.
LINE asks you to pick a provider, which is the organization that owns the channel. Two constraints make this a decision rather than a formality.
You can't change or remove the provider afterwards. And a person receives a different user ID under each provider, so moving an account later would break every stored user reference. An existing provider only appears in the list when your account holds the admin role on it, so a provider that seems to be missing is usually a permissions problem rather than an absent one.
Pick the provider that owns your related channels, and avoid putting unrelated services under one provider for convenience.
A new channel arrives with greeting messages and auto-reply messages enabled, which means a person gets one LINE-managed response and one agent response to the same message.
Reach the settings from either console:
1. In Official Account Manager, open **Settings** -> **Response settings**.
2. Or in the Developers Console, open the channel's **Messaging API** tab, where **Greeting messages** and **Auto-reply messages** each carry an **Edit** link that opens Official Account Manager at the right place.
LINE recommends disabling both for a first Messaging API bot, and explains why under [settings on LINE Official Account Manager](https://developers.line.biz/en/docs/messaging-api/building-bot/#line-manager-settings). Disable both when the agent should own every reply. Keeping a greeting message is reasonable if you author it deliberately, but leaving the defaults on reads to users as a broken bot rather than as a settings problem.
All three credential values live in the Developers Console, spread across two tabs of the same channel.
1. Sign in at [developers.line.biz/console](https://developers.line.biz/console/).
2. Select your provider, then select the Messaging API channel.
3. Open the **Basic settings** tab and copy **Channel secret**. You need the admin role on the channel to see it.
Take care not to grab the **Channel ID** or **Your user ID** from the same screen. Both sit nearby, both look like credentials, and neither works.
Open the **Messaging API** tab. LINE offers four token types, and this screen issues only one of them.
| Token type | Validity | Limit per channel |
| -------------------------------- | ------------------- | ----------------- |
| User-specified expiration (v2.1) | Up to 30 days | 30 |
| Stateless | 15 minutes | No limit |
| Short-lived | 30 days | 30 |
| Long-lived | Until you revoke it | 1 |
The long-lived token is the one with an **Issue** control on this tab. The other three come from API calls rather than the console, so choosing them means building issuance into your own tooling.
LINE recommends the v2.1 token, and that recommendation costs you a rotation schedule. Pick the long-lived token if you'd rather not build that, and accept that a single indefinite credential carries more risk. Whichever you choose, copy the value straight into your secret manager.
Reissuing a long-lived token normally kills the previous one immediately. LINE lets you extend the outgoing token's validity by up to 24 hours when you reissue, which gives you a window to update Artemis without dropping messages. Use it.
The console never shows this value, so you call for it.
1. Use LINE's [Get bot info](https://developers.line.biz/en/reference/messaging-api/#get-bot-info) endpoint with the channel access token you just issued.
```bash theme={null}
curl -v -X GET https://api.line.me/v2/bot/info \
-H "Authorization: Bearer {channel access token}"
```
2. Copy the `userId` from the response.
The value begins with `U` and matches the `destination` field LINE puts in every webhook for this channel. Run this from a secure terminal rather than a shared one, since the command carries your token.
While you're on the **Messaging API** tab, find the QR code or add-friend link. You'll need it to test, and it's easier to grab now than to come back for.
***
## Artemis channel configuration
Create the connection before you verify the webhook in LINE. LINE's verification request has to resolve to an active connection and authenticate with that connection's Channel Secret, so an unsaved connection fails verification.
1. Open Artemis and select the project.
2. Go to **Deployments** -> **Channels** -> **LINE** -> **+ New**. The **New LINE Connection** dialog opens.
3. Configure the following fields:
| Artemis connection field | Source / Notes | What it controls |
| ------------------------------ | -------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Display Name | You choose it | The label operators see in the connections list. Name it for the Official Account and the environment it serves, because a project can hold several LINE connections. Routing ignores this value. |
| Destination ID | The `userId` from Get bot info. See [LINE setup](#line-setup). | The routing key. It begins with `U`. |
| Channel Access Token | Developers Console > channel > **Messaging API** tab | The credential for every outbound call Artemis makes to LINE. |
| Channel Secret | Developers Console > channel > **Basic settings** tab | The key Artemis uses to verify the signature on each inbound event. |
| Environment | Your published environments | The environment whose active deployment answers incoming messages. Leave the working copy default only while you develop. |
| Provider Verification Strength | Defaults to **Weak** | How far Artemis trusts LINE's identity assertion when it links a person to an existing session. **Weak** suits most deployments. Choose **Strong** only when you trust those assertions enough to base continuity and account-linking decisions on them. |
| Initial Status | Defaults to **Active** | Whether the connection starts handling messages. Set it to **Active**, because LINE's verification resolves only when the connection is already active. |
4. Select **Create**.
5. Open the connection and copy the **Webhook URL** from the **Overview** tab. You need it for the next section.
***
## Webhook configuration in LINE
LINE separates saving the URL from switching delivery on, so a verified webhook can still deliver nothing. Complete all three parts, in the Developers Console on the channel's **Messaging API** tab.
1. Find **Webhook settings**.
2. Select **Edit** under **Webhook URL**.
3. Paste the Artemis endpoint exactly as shown and select **Update**.
LINE accepts one endpoint per channel. Don't append the Destination ID, the Channel ID, a project ID, or any connection identifier, because Artemis routes from the signed body rather than the path.
LINE also requires HTTPS with a certificate from a widely trusted authority. Self-signed certificates fail, and so does a server missing its intermediate certificates, which is a common cause of a verification failure that looks like a LINE problem.
Select **Verify**. LINE posts an event-free payload to the endpoint, and Artemis responds once it has resolved the connection and verified the signature. LINE reports **Success** when this works.
Treat anything else as a stop. A timeout, a non-200 response, a TLS error, and a signature failure each point somewhere different, and continuing past one means debugging later with live users watching.
Turn on **Use webhook**.
This is the step people miss. Saving a verified URL without this toggle leaves the channel looking correctly configured while message events never reach Artemis.
Enable redelivery only when your operations policy requires retries after a non-2xx response.
LINE can deliver the same webhook more than once when redelivery is on, and it can change event order during redelivery. Your agent logic has to tolerate both, so rely on event IDs rather than arrival order before you turn this on.
The channel's **Security** tab accepts a list of IP addresses, individually or in CIDR notation, that may call the LINE Platform with a long-lived token.
This narrows the blast radius of an indefinite credential considerably, so it's worth doing whenever you pick that token type. LINE covers the setting under [restrict who can call the API](https://developers.line.biz/en/docs/messaging-api/building-bot/#configure-security-settings). It doesn't apply to the other three.
### Validation checklist
| Validation item | Expected result |
| :---------------------------- | :-------------------------------------------------------------------------------------------------------------- |
| Complete LINE setup | Official Account created, Messaging API enabled, and greeting and auto-reply messages disabled. |
| Collect credentials | Channel Secret, Channel Access Token, and the `U`-prefixed Destination ID copied from the matching channel. |
| Create the Artemis connection | Connection saved as **Active** with the Destination ID, both credentials, and the intended environment. |
| Register the webhook URL | LINE reports **Success** when you select **Verify**. |
| Enable delivery | **Use webhook** shows as turned on. |
| Send a live message | A real LINE conversation produces exactly one agent reply. See [Verify the connection](#verify-the-connection). |
## Verify the connection
Artemis has no synthetic test for this channel, so a real conversation is the only end-to-end proof.
1. Add the Official Account as a friend by scanning the QR code or using the add-friend link on the **Messaging API** tab. Test from an ordinary LINE account rather than an identity that exists only as a console administrator, because the two behave differently.
2. Send a short message you can search for later, and confirm the agent replies in the same chat.
3. Count the replies. Two responses to one message means greeting messages or auto-reply messages are still enabled, not that the agent ran twice.
4. Send each input type your agent supports, and confirm its authored behavior for each. Receiving a media event isn't the same as handling it, so test the authored path rather than only the delivery.
5. Test groups only if you need them. Enable **Allow bot to join group chats** in Official Account Manager, invite the bot, then message or mention it. Confirm sessions stay scoped to the LINE source, so a group conversation and a one-to-one conversation with the same person don't merge.
***
## Secure the connection
Both LINE credentials are secrets, and they do opposite jobs. The Channel Secret authenticates what comes in; the Channel Access Token authorizes what goes out.
Artemis computes HMAC-SHA256 over the unchanged raw request body and compares it with the `X-Line-Signature` header. Any proxy or middleware in front of Artemis has to leave the signed body untouched, because a single changed byte fails verification as surely as a wrong secret does.
Rotation invalidates immediately on both credentials. Reissuing a Channel Secret kills the old secret, and reissuing a long-lived access token kills the previous token unless you use the 24-hour extension. Coordinate the Artemis update with the provider-side change rather than doing them hours apart, and revoke any token you suspect someone has copied, because a compromised token can broadcast to every friend of the Official Account.
Keep both values out of browser code, screenshots, tickets, and source control, and update Artemis the moment LINE reissues or revokes either one.
Use distinct providers or channels for development and production, or at minimum distinct credentials and connections. Pointing two environments at one webhook mixes test traffic into real conversation history.
***
## Manage the channel connection
Opening a connection shows four tabs. The delete control sits beside the connection name.
**Connection Summary** reports the connection's state and identity.
| Field | Description |
| --------------------------- | ----------------------------------------------------------------------------- |
| **Status** | Whether the connection currently handles messages. |
| **Created** and **Updated** | Date and time of creation, and of the last change. |
| **Environment** | The environment whose deployment answers messages. |
| **Source Type** | Reads `Channel Connection`. |
| **Source ID** | Identifies the connection uniquely. Quote it when you raise a support ticket. |
**Setup Instructions** shows the **Webhook URL** to register in the Developers Console and the **Destination ID** this connection matches events to, each with a copy control. Check the Destination ID here first when messages arrive and no session appears.
Artemis encrypts credentials after you save them, so each field reads as saved rather than showing its value. Leave a field empty to keep the current value, or enter a new one to replace it.
| Field | Description |
| ------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Use Auth Profile** | Draws the credentials from a saved auth profile instead of the fields below. Prefer it when the same credentials serve more than one connection, since a rotation then touches one profile. |
| **Channel Access Token** | Replace it here whenever you reissue the token in the Developers Console, and do it promptly, because the old token stops working at once. |
| **Channel Secret** | Replace it here if another administrator reissues the secret. Until you do, every inbound event fails signature verification. |
Select **Save Credentials** to apply your changes.
Under **General**, rename the connection with **Display Name**, and revisit **Provider Verification Strength** if your trust posture for this Official Account changes.
Under **LINE Settings**, **Destination ID** appears read-only. Artemis routes inbound events by this value, so changing it would orphan the connection. Create a new connection to serve a different Official Account.
**Authorization Message** controls what the person sees when a tool needs them to authorize something before the conversation continues. Write the template with these variables.
| Scope | Variables | Use |
| ------------ | -------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------- |
| Message | `{{total}}`, `{{completed}}`, `{{remaining}}` | Summarize progress across every pending authorization, typically in a lead-in line above the list. |
| Repeat block | `{{#authorizations}}` and `{{/authorizations}}` | Wrap the section Artemis repeats once per pending authorization. |
| Item | `{{profileName}}`, `{{authLink}}`, `{{authUrl}}`, `{{index}}`, `{{count}}` | Identify and link each authorization inside the repeat block. |
Item variables resolve only inside the repeat block. Use the preview to check the wording, and remember it fills from live pending authorizations at runtime.
Select **Save Changes** to apply your changes.
Choose which deployed version of the agent answers messages on this connection.
Under **Agent Version**, set **Environment** to the environment you want the connection to follow. **Active Deployment** then shows the version currently serving traffic and when someone deployed it.
Check this pair when the channel connects but the agent behaves like an older build. The connection follows whatever the environment currently has deployed, not the version you last edited. Select **Save Changes** after you switch the environment.
***
## Troubleshoot connection issues
| Symptom | Likely cause | Recommended action |
| --------------------------------------------- | ------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Verify doesn't report success | The connection isn't active, the endpoint isn't reachable, or the certificate chain is incomplete | Confirm the connection exists and is active, that the Artemis endpoint is reachable over public HTTPS with a certificate from a trusted authority and a complete chain, that the URL carries no extra path segment, and that LINE receives a 200 response. |
| Artemis reports no connection found | The Destination ID holds the wrong identifier | Replace it with the `U`-prefixed `userId` from Get bot info. The Channel ID, the Bot basic ID, and personal user IDs don't route. |
| Signature verification fails | The Channel Secret doesn't match, or a proxy rewrote the body | Copy the Channel Secret from the matching channel's **Basic settings**, check whether another administrator reissued it, and confirm no proxy or middleware rewrites the raw body. |
| Verification succeeded but no messages arrive | **Use webhook** is off | Turn on **Use webhook**. A saved and verified URL delivers nothing until you do. |
| Messages arrive but the agent doesn't reply | The access token expired, someone revoked it, or no deployment can run | Confirm the Channel Access Token is current, the connection is active, and the bound environment has a runnable deployment. A v2.1 token past its 30-day ceiling produces exactly this symptom. |
| People receive two replies | LINE's own automatic replies are still enabled | Disable greeting messages and auto-reply messages, or author them so they don't overlap with the agent. |
| Direct messages work but groups don't | The bot can't join group chats, or it joined before you changed the setting | Enable **Allow bot to join group chats**, reinvite the bot if you changed the setting after inviting it, and confirm the test event comes from the expected group or room. |
| Text works but media doesn't | The event type, the token, the size limit, or the agent flow blocks it | Confirm Artemis supports the event type, the token can download message content, attachment limits allow the file, and the agent flow handles attachments. |
| The provider you want isn't in the list | Your account lacks the admin role on it | Ask a provider admin to grant the role rather than creating a second provider. |
***
## LINE reference
Use these LINE pages and consoles when you need detail beyond what this article covers.
| Resource | Use it for |
| -------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------ |
| [LINE Official Account Manager](https://manager.line.biz/) | Creating the Official Account, enabling the Messaging API, response settings, group chat permission, and admin roles. |
| [LINE Developers Console](https://developers.line.biz/console/) | Channel credentials, webhook settings, the security tab, and the friend-add QR code. |
| [Get started with the Messaging API](https://developers.line.biz/en/docs/messaging-api/getting-started/) | LINE's own walkthrough of Business ID registration, account creation, and provider selection. |
| [Build a bot](https://developers.line.biz/en/docs/messaging-api/building-bot/) | Tokens, the webhook URL, verification, and the certificate requirements. |
| [Channel access tokens](https://developers.line.biz/en/docs/basics/channel-access-token/) | How the four token types differ and which suits your rotation policy. |
| [Messaging API reference](https://developers.line.biz/en/reference/messaging-api/) | Endpoint detail, including [Get bot info](https://developers.line.biz/en/reference/messaging-api/#get-bot-info) and webhook event objects. |
**Related articles:**
* [Channels](/agent-platform/channels)
* [Set up Messenger](/agent-platform/channels/set-up-messenger)
* [Set up WhatsApp](/agent-platform/channels/set-up-whatsapp)
* [Set up Telegram](/agent-platform/channels/set-up-telegram)