---
schema_version: "1"
id: 296f98049153aef6a9e7accc1c36646d35ddd71933641ecc2e92fd5bb70bcba2
title: Identifying Resources Using LUIDs-Tableau Server REST API
collection: tableau
version: next
locale: en-us
portal_url: https://docs.salesforce.com/tableau/next/en-us/api/rest_api/REST/rest_api_concepts_luid.md
canonical_url: https://help.tableau.com/v0.0/api/rest_api/en-us/REST/rest_api_concepts_luid.htm
source_site: help.tableau.com
content_type: documentation
content_hash: 4cc8fc034890e93114001f1cdc03013fdb7cd677c954600cc6b4aaeaaa39dd78
description: Resources on Tableau Server typically have a friendly name, such as "Default" for a site name, "Developers" for a group, and "Adam" for a user
---
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# Identifying Resources Using Locally Unique Identifiers (LUIDs)

Resources on Tableau Server typically have a friendly name, such as "Default" for a site name, "Developers" for a group, and "Adam" for a user. These are the names that you see when you work in the Tableau Server user interface.

These resources are also identified internally by Tableau Server using a locally unique identifier (LUID). LUIDs are 32-character hexadecimal strings separated by hyphens in a format like this: `9f8e7d6c5b-4a3f-2e1d-0c9b-8a7f6e5d4c`.

Tableau Server uses LUIDs because friendly names might change or be reassigned. For example, you can change the friendly name of a user without affecting the user's permissions or membership in groups, because the LUID for that user does not change. In addition, you might delete a user named Adam because that user has left your company. If you later create a new user named Adam for a new employee, that user identity in Tableau Server should be distinct from the older identity, and using a different LUID for the new user guarantees that.

**Note**: A LUID is unique for each content type within a site. A project and a workbook on the same site could theoretically have the same LUID, but that is unlikely. It's more likely that a LUID could be repeated on another site. For example: two workbooks on two different sites could have the same LUID.

## Getting LUIDs for Resources

When you create a new resource, or if you query the server for a list of resources, the server returns the LUIDs for the resource. For example, [Sign In](https://help.tableau.com/v0.0/api/rest_api/en-us/REST/rest_api_ref.htm#sign_in), [Create Site](https://help.tableau.com/v0.0/api/rest_api/en-us/REST/rest_api_ref.htm#create_site), [Create User](https://help.tableau.com/v0.0/api/rest_api/en-us/REST/rest_api_ref.htm#create_user), [Get Users in Site](https://help.tableau.com/v0.0/api/rest_api/en-us/REST/rest_api_ref.htm#get_users_in_site), and [Query Groups](https://help.tableau.com/v0.0/api/rest_api/en-us/REST/rest_api_ref.htm#query_groups) all return LUIDs for resources.

The following example shows the return value for a call to [Query Groups](https://help.tableau.com/v0.0/api/rest_api/en-us/REST/rest_api_ref.htm#query_groups), which includes the friendly name for each group as well as the group's LUID:

```
<?xml version="1.0" encoding="UTF-8"?>
  <tsResponse version-and-namespace-settings >
  <pagination pageNumber="1" pageSize="100" totalAvailable="2"/>
  <groups>
    <group id="1f2f3e4e5-d6d7-c8c9-b0b1-a2a3f4f5e6e" name="Managers">
      <domain name="local"/>
    </group>
    <group id="9a8a7b6b5-c4c3-d2d1-e0e9-a8a7b6b5b4b" name="IT">
      <domain name="local"/>
    </group>
  </groups>
</tsresponse>
```

## Using LUIDs in API Calls

When you specify a resource in a call, you typically need to provide the resource's LUID. For example, all calls except [Sign In](https://help.tableau.com/v0.0/api/rest_api/en-us/REST/rest_api_ref.htm#sign_in) call require you to include a site LUID in the URI, as in this example of calling [Query Groups](https://help.tableau.com/v0.0/api/rest_api/en-us/REST/rest_api_ref.htm#query_groups):

```
http://my-server/api/3.29/sites/9a8b7c6d5-e4f3-a2b1-c0d9-e8f7a6b5c4d/users
```

Similarly, if you want to update user information using the [Update User](https://help.tableau.com/v0.0/api/rest_api/en-us/REST/rest_api_ref.htm#update_user) API, you include the LUIDs for both the site and the user in the URI, as in this example:

```
http://my-server/api/3.29/sites/9a8b7c6d5-e4f3-a2b1-c0d9-e8f7a6b5c4d/users/9f9e9d9c8-b8a8-f8e7-d7c7-b7a6f6d6e6d
```

In the preceding example, `9a8b7c6d5-e4f3-a2b1-c0d9-e8f7a6b5c4d` is the site ID, and `9f9e9d9c8-b8a8-f8e7-d7c7-b7a6f6d6e6d` is the ID of the user to update.