# Usernames

The WallStreet Adapter identifies a user to WSS core by the user’s web-application username (for example, the username with which the user logged in to [Caplin FX Corporate](../fx-corporate/index.md)).

You may also see the web-application username referred to elsewhere in the Caplin documentation as the single sign-on (SSO) username. It’s the username with which the user is authenticated with [Caplin Liberator](../caplin-platform/liberator/index.md) using a [Caplin KeyMaster](../caplin-platform/keymaster/index.md) authentication token.

**❗ IMPORTANT**\
Each user’s web-application username must be identical to their WSS core username.

If you’re a developer, and you’re installing Caplin’s Wallstreet Adapter with Caplin FX Corporate locally on your development machine, you may need to configure web-application user accounts manually. For more information, see [Caplin FX Corporate: Creating user accounts in development](../fx-corporate/fxcorp-creating-user-accounts-in-development.md).

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**See also**:

* [Caplin FX Corporate: Creating user accounts in development](../fx-corporate/fxcorp-creating-user-accounts-in-development.md)
* [Liberator: User Authentication and Permissioning](../caplin-platform/liberator/liberator-user-authentication-and-permissioning.md)
* [KeyMaster](../caplin-platform/keymaster/index.md)