# Connect CrmServiceClient using Azure AD App Client ID & Client Secret for C# SDK

After depecation announcemnt of Dynamics 2011 Organization Service Endpoint in late 2018 and recommendation on using OAuth authentication & Dynamics 365 WebAPI, there was uncertainity for developers who were using/planning to use 3rd party integartion using C# SDK.

Ref: [https://crmtipoftheday.com/1155/the-clock-is-ticking-on-your-endpoint/](https://crmtipoftheday.com/1155/the-clock-is-ticking-on-your-endpoint/)

Ref: [https://community.dynamics.com/crm/f/microsoft-dynamics-crm-forum/311096/is-organization-service-is-going-to-be-deprecated](https://community.dynamics.com/crm/f/microsoft-dynamics-crm-forum/311096/is-organization-service-is-going-to-be-deprecated)

Finally, `CrmServiceClient` provides option to connect to organization service using Client Id & Client Secret. Let’s try it out.

### Why to use Client ID & Client Secret to Authenticate

*   Only minor code chanegs required in existing code.
*   OAuth is safer than using password based authenticaton.
*   Save user licencing cost by using Application User

### Sample Code

As part of initial setup Application User & Azure AD App is required if you don’t have it already please refer to Step 1 & Step 2 in [this artice.](https://www.ashishvishwakarma.com/Dynamics-365-Single-Tenant-Server-2-Server-Authentication-Azure-Active-Directory-Access-Token/) Once you have all the details, prepare connection string as shown below and use **AuthType=ClientSecret** here.

    public static IOrganizationService GetOrganizationServiceClientSecret(string clientId, string clientSecret, string organizationUri)
    {
        try
        {
            var conn = new CrmServiceClient($@"AuthType=ClientSecret;url={organizationUri};ClientId={clientId};ClientSecret={clientSecret}");
    
            return conn.OrganizationWebProxyClient != null ? conn.OrganizationWebProxyClient : (IOrganizationService)conn.OrganizationServiceProxy;
        }
        catch (Exception ex)
        {
            Console.WriteLine("Error while connecting to CRM " + ex.Message);
            Console.ReadKey();
            return null;
        }
    }
    
    IOrganizationService orgService = GetOrganizationServiceClientSecret(
                     "<Client Id obtained from Azure AD App>",
                     "<Client Secret obtained from Azure AD App>",
                     "<Organization Uri>");
    
    var response = orgService.Execute(new WhoAmIRequest());
    

All the necessary packages should be installed, package **Microsoft.CrmSdk.XrmTooling.CoreAssembly** version should be 9.1.0.13 or higher in order to connect using ClientSecret. [see release notes.](https://www.nuget.org/packages/Microsoft.CrmSdk.XrmTooling.CoreAssembly/9.1.0.38/)

![nuget-packages](../assets/2020-03-02/packages.png)

You can find this code on my [GitHub.](https://github.com/AshV/Dynamics365ConsoleCaller)

Feel free to get back in case of any suggestions/queries.