The authentication API provides third-parties with a secure means of creating Last.fm user sessions over the Last.fm API, for deeper integration with our platform. All write services require authentication.
Head over to your api accounts page, and select the account you wish to configure. You need to supply an application name, a description and an optional logo. Each of your account pages contains an API key and secret; you will need both to use the API.
If you're building on a standalone device such as a mobile phone, see the mobile how-to for more details.
In some cases, you may want to choose a different authentication path from the obvious (e.g. a mobile app could well use the desktop path if there's a web browser on the device). If in doubt, check them all out.