---
layout: default
navsection: api
navmenu: Schema
title: User

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A **User** represents a person who interacts with Arvados via an ApiClient.

h2. Methods

See "users":{{site.baseurl}}/api/methods/users.html

h2. Resource

Each User has, in addition to the usual "attributes of Arvados resources":{{site.baseurl}}/api/resources.html:

table(table table-bordered table-condensed).
|_. Attribute|_. Type|_. Description|_. Example|
|email|string|||
|username|string|The username used for the user's git repositories and virtual machine logins.  Usernames must start with a letter, and contain only alphanumerics.  When a new user is created, a default username is set from their e-mail address.  Only administrators may change the username.||
|first_name|string|||
|last_name|string|||
|identity_url|string|||
|is_admin|boolean|||
|prefs|hash|||
|default_owner_uuid|string|||
|is_active|boolean|||
|writable_by|array|List of UUID strings identifying Groups and other Users that can modify this User object.  This will include the user's owner_uuid and, for administrators and users requesting their own User object, the requesting user's UUID.||