LINE signs users in with their LINE account — the messaging identity most users in Japan, Taiwan, and Thailand already carry.

## Copy the redirect URI

In the [Authdog console](https://console.authdog.com), select the project and environment, open **Authentication > Providers**, find **LINE**, and click **Enable**. Copy the redirect URI shown in the form:

```url
https://identity.authdog.com/api/v1/callback/<connectionId>
```

## Create the application

1. Open the [LINE Developers console](https://developers.line.biz/console/) and create a provider, then a **LINE Login** channel.
2. Under **LINE Login settings**, add the redirect URI from Authdog to the **Callback URL** list.
3. Enable the `email` permission — it requires submitting a privacy policy and applying for the option.
4. Copy the **Channel ID** and **Channel secret** from **Basic settings**.

## Configure Authdog

| Field | Value |
| --- | --- |
| **Client ID** | The LINE **Channel ID** |
| **Client Secret** | The LINE **Channel secret** |

Save, then toggle the connection **active**.

## What LINE returns

Authdog requests the `openid profile email` scopes and reads the profile from `https://api.line.me/v2/profile`.

The profile endpoint returns the LINE user id, display name, and picture. The email, when granted, arrives in the ID token.

Email access is an opt-in that LINE reviews. Until it is approved, users arrive with a display name and identifier only.

## Test it

1. Open your environment's hosted sign-in page, or link to `https://identity.authdog.com/api/v1/signin/<connectionId>`.
2. Select the LINE button and complete the flow.
3. Confirm the user appears under **Users** in the console with a LINE identity linked.

## Troubleshooting

| Symptom | Cause |
| --- | --- |
| `400 invalid redirect_uri` | The callback URL is missing from the channel |
| No email claim | The email permission has not been approved for this channel |
| Redirect or callback URL error | The URI registered with the provider does not match Authdog's exactly |
| Works in one environment only | Each environment has its own `connectionId`, and so its own redirect URI to register |

## Related

| Read | To learn how to |
| --- | --- |
| [Connectors](/docs/connectors) | Set up any other social provider |