To authenticate with OAuth, you must create a custom OAuth application registered in Linear. A custom application provides the OAuthClientId and OAuthClientSecret that the add-in uses to obtain OAuth tokens.

To create a custom OAuth application:

1. Log in to Linear and open Settings > API > OAuth applications.
2. Select Create new and provide a name and (optionally) an icon.
3. Set the Callback URL (redirect URI). For desktop use, set it to http://localhost:33333.
4. Create the application and note the Client ID and Client Secret.
5. Choose the scopes the integration needs (for example, read for read-only access, or read,write to also create and modify data). By default, the add-in requests read,write.