Home > CRM, Dynamics 365 > D 365 Development – Different ways to connect/authenticate Dynamics 365

D 365 Development – Different ways to connect/authenticate Dynamics 365

There was a question posted on my blog by a Dynamics 365 newbie developer on how to authenticate to Dynamics 365 online from his console application.

In this article I am going to detail various ways to connect to Dynamics 365.

Option 1 – Connect using Dynamics 365 SDK assemblies:

  • You need Dynamics 365 SDK assemblies, If you are creating plug-ins, custom workflow activities, or custom XAML workflows and performing operations (i.e., Create/Update/Execute/Retrieve)
  • Refer Steps to create a basic plug-in
  • Download the latest SDK assemblies from nuget.

Option 2 – Connect using XRM Tooling assemblies:

  • If you are building .Net applications (i.e., Console/Web/Windows) use the XRM Tooling assemblies to connect to the Dynamics Application.
  • XRM tooling enables you to connect to your Dynamics 365 instance by using connection strings.
  • Refer article for different types of Connection strings based on your Dynamics deployment (i.e., One-prem/IFD/Office 365 etc..)
  • Below is the sample code to connect to your instance from Console:


  • Download the latest SDK assemblies from nuget in your console application.
  • Make sure you refer below .dlls in your console class file.
    • using Microsoft.Xrm.Sdk;
    • using Microsoft.Xrm.Tooling.Connector;


// Add below Connection string to your console’s App.config file


<add name=”Xrm” connectionString=”Url=https://{orgname}.crm.dynamics.com; Username=rajeevpentyala@yourdomain.onmicrosoft.com; Password=XXXXXXX;authtype=Office365;Timeout=20″ />



// Declare the Service Variables

private static OrganizationServiceProxy _serviceProxy;

private static IOrganizationService _service;

// Read the connection string configured in App.config file

var connectionString = ConfigurationManager.ConnectionStrings[“Xrm”].ConnectionString;

var crmConn = new CrmServiceClient(connectionString);

using (_serviceProxy = crmConn.OrganizationServiceProxy) {

_service = _serviceProxy;

var reqWhoAmI = new WhoAmIRequest();

var resp = (WhoAmIResponse)_service.Execute(reqWhoAmI);

var buID = resp.OrganizationId.ToString();

var userID = resp.UserId.ToString();


  • Refer my post on steps to connect to D 365 using Xrm.Tooling.Connector

Option 3 – Connect using Dynamics 365 Web API:

  • What if you want to connect to Dynamics from a Non- .NET applications (i.e., Java/PHP applications), the solution is Web API.
  • Web API provides development experience that can be used across a wide variety of programming languages, platforms, and devices.
  • Web API uses no DLL approach; Unlike above 2 approaches (i.e., XRM Tooling/SDK Assemblies), you don’t need to refer assemblies to connect to Web API.
  • There are 3 different ways to connect to Web API
    1. Using JavaScript in from Dynamics web resources (i.e., Jscript files, HTML, Ribbon). We don’t need to include any authentication code as the logged-in user is already authenticated by the application.
    2. If your Dynamics 365 is On-premise, you can authenticate Web API by passing User’s network credentials.
    3. If your Dynamics 365 is Online or IFD, you must use OAuth to connect.
  • Refer this article on steps to connect to Web API.
  • Web API is very convenient to use and test.
  • With Postman tool you can connect to Web API and perform operations. Refer article

Below is the Flow diagram gives idea on when to use which option among the 3 options:



Categories: CRM, Dynamics 365 Tags: , ,

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: