Discover the URL for your organization using the Web API

The Discovery service for the Dynamics 365 for Customer Engagement Web API enables your applications to determine at run-time the organizations, also known as instances, that the logged-on user belongs to. You can retrieve detailed information about those instances like the instance service URL, the Customer Engagement release version, the instance ID and more. You can use standard $filter and $select parameters to a Web API service request to customize the returned list of instance data.


The documentation that is applicable to online users is now available in the Power Apps documentation at: Discover the URL for your organization using Web API.

Client applications may need access to a Customer Engagement instance where the instance URL may change over time. For example, when a Customer Engagement instance is moved from one on-premises datacenter to another. The Discovery service allows clients instance to persist the instance ID or instance unique name and then use the Discovery service to look-up the current instance access URL.

Information provided by the Discovery service

Organization information is stored in the Instance entity of the Discovery service. To see the kind of information contained in that entity, send an HTTP GET request to the service for one of your instances.

GET https://dev.{servername}/api/discovery/v9.1/Instances(UniqueName='myorg')  

In the above example, the discovery service is used to obtain the organization information of the instance with a unique name of "myorg". More details about this request is expanded upon later in this topic.

Scope of the returned information

For the regional discovery service, the Instances entity set, returns the set of instances that the user has access to in a particular geography, when no filters are applied. The returned data has a scope as described below.

  • Does not include instances where the user's account is disabled

  • Does not include instances where users have been filtered out based on an instance security group

  • Does not include instances where the user has access as a result of being a delegated administrator

  • If the calling user has access to no instances, the response simply returns an empty list

How to access the Discovery services

In general, the Web API address of the Discovery service has the following format: <service base address>/api/discovery/. The addresses for each deployment type are identified below. You can easily find the Web API addresses and version number for your deployment in the Customer Engagement web application by navigating to Settings > Customization > Developer Resources.

The service base address of the Discovery service for an on-premises or IFD deployment is : http[s]://{servername}/ or http[s]://dev.{servername}/. This results in the service address of http[s]://{servername}/api/discovery/ or http[s]://dev.{servername}/api/discovery/.

Using the Discovery service

An entity set named Instances is used to obtain instance information. You can use $select and $filter with the Instances entity set to filter the returned data. You can also use $metadata to obtain the metadata document of the service.


On-premise or IFD instances of the Discovery OData V4 RESTful API adopt the authentication model of their deployment, supporting either Integrated Windows Authentication (IWA) or OAuth tokens from a trusted token provider. Web Application Session authentication is not supported.

Web API versioning

Versioning of the Discovery service for a datacenter or on-premises/IFD is supported and is consistent with version numbering as used by the Organization service. For example:

GET https://dev.{servername}/api/discovery/v9.1/Instances(UniqueName='myorg')  

CORS support

The Discovery service RESTful API supports the CORS standard for cross-origin access as does the Web API. For more information about CORS support see Use OAuth with Cross-Origin Resource Sharing to connect a Single Page Application.


  • Get the details of a specific instance. If you leave out the GUID, all instances that the authenticated user has access to are returned.

    GET https://dev.{servername}/api/discovery/v9.1/Instances(<guid>)  
  • You can use the UniqueName attribute as an alternate key.

    GET https://dev.{servername}/api/discovery/v9.1/Instances(UniqueName='myorg')  
  • Retrieve a list of available instances, filtered by production type.

    GET https://dev.{servername}/api/discovery/v9.1/Instances?$select=DisplayName,Description&$filter=Type+eq+0   
  • Retrieve a specific instance's ID property value.

    GET https://dev.{servername}/api/discovery/v9.1/Instances(UniqueName='myorg')/Id/$value  

See also

Web API Global Discovery Service sample (C#)