This is how to set up a Magento seller account for AtomicSeller:

Store name: This is the full name of the store used only in user interface.
Store key: This is the main identifier of the store essential when using webservices.
Merchant key: This is the main identifier of the merchant (Optional except if you have multiple stores and multiple merchants)
Store API URL: This is the store path followed by “/rest/all/V1/”
User name: API user name
Password: API user password. This field is hidden for security reasons.
How to get an API key ?
You must register a web service on Magento Admin. Use the following general steps to set up Magento to enable web services.
- If you are using token-based authentication, create a web services user on Magento Admin by selecting System > Permission > All Users > Add New User. (If you are using session-based or OAuth authentication, you do not need to create the new user in the Admin.)
- Create a new integration on Magento Admin. To create an integration, click System > Extensions > Integration > Add New Integration**. Be sure to restrict which resources the integration can access.
- Use a REST or SOAP client to configure authentication.
More information here:
Magento version 1.7.0.2
Source
http://www.aschroder.com/2012/04/introduction-to-the-magento-rest-apis-with-oauth-in-version-1-7/






