Build and package plug-in code

This article describes constraints and limitations you need to know about when you're configuring and building an assembly for your Microsoft Dataverse plug-in.

Plug-in assembly constraints

When you build a plug-in project, keep the following output assembly constraints in mind.

Use .NET Framework 4.6.2

Plug-in and custom workflow activity assembly projects must target .NET Framework 4.6.2. Assemblies that are built using later versions of the .NET Framework should generally work. However, if the plug-in code uses any features introduced after 4.6.2, a runtime error occurs.

Limit assemblies to 16 MB

Your assembly can include multiple plug-in classes or types and even custom workflow activities, but it can't be larger than 16 MB. As a best practice, we recommend that you consolidate plug-ins and workflow assemblies into a single assembly, as long as the size remains below 16 MB.

Sign assemblies before registering them

If you're not using the dependent assemblies capability, assemblies must be signed before you can register them with Dataverse. To sign the assembly, use the Visual Studio Signing tab in your project's properties or the Sn.exe (Strong Name Tool) command

NuGet CoreAssemblies are in the sandbox

If you add the Microsoft.CrmSdk.CoreAssemblies NuGet package to your project, the required Dataverse assembly references are also added, but the assemblies themselves aren't uploaded with your plug-in assembly. They already exist in the server's sandbox runtime where your code executes

Dependent assemblies


The dependent assembly capability is so important to plug-in development that you should consider using it from the start, even if you don't have an immediate need. Adding support for dependent assemblies to your plug-in project is much more difficult later in the development cycle.

We don't support ILMerge. The dependent assemblies capability offers the same functionality as ILMerge and more.

Use the dependent assembly capability to include other required .NET assemblies or resources, like localized strings, with your plug-in assembly in a single NuGet package that's uploaded to the Dataverse server during registration.

The NuGet package file is stored in the PluginPackage table. The contents of the package are stored in file storage rather than in the SQL database.

When you upload your NuGet package, any assemblies that contain classes that implement the IPlugin interface are registered in the PluginAssembly table and associated with the plug-in package. As you develop and maintain your project, you continue to update the PluginPackage table row and changes to the related plug-in assemblies are managed on the server.

At runtime, Dataverse copies the contents of the NuGet package from the PluginPackage row and extracts it to the sandbox runtime. This way, any dependent assemblies needed for the plug-in are available.


The name and version of the plug-in package cannot be changed once created. Attempting to do so using an API call results in an error.

Signed assemblies are not required

You aren't required to sign plug-in assemblies used in plug-in packages.

When you register individual plug-in assemblies without the dependent assemblies capability, signing is required because it provides a unique name for the assembly. But with plug-in assemblies in a plug-in package, the assemblies are loaded on the sandbox server using a different mechanism, so signing isn't necessary.


If you sign your assemblies, be aware that signed assemblies can't use resources that are contained in unsigned assemblies. If you sign your plug-in assemblies or any dependent assembly, all the assemblies that those assemblies depend on must be signed.

If any signed assemblies depend on unsigned assemblies, you get an error like this: "Could not load file or assembly AssemblyName, Version=Version, Culture=neutral, PublicKeyToken=null or one of its dependencies. A strongly-named assembly is required."

Dependent assemblies limitations

The following limitations apply when you use plug-in dependent assemblies:

  • Workflow extensions, also known as custom workflow activities, aren't supported.
  • On-premises environments aren't supported.
  • Unmanaged code isn't supported. You can't include references to unmanaged resources.

Performance consideration when importing or registering a plug-in package

Plug-in packages containing assemblies with a large number (hundreds to thousands) of classes that implement IPlugin will take a relatively long time to import into Dataverse.

We have seen import times of fifteen (15) minutes for a thousand plug-in types. This duration applies regardless if you are importing a solution using an API call or through the Web UI, or registering the package with the Plug-in Registration tool.

Create a plug-in package

You can place your plug-in assembly and any dependent assemblies together in a NuGet package, and then register and upload the package to the Dataverse server. If your plug-in project doesn't require any dependent assemblies at runtime other than what ships in the Microsoft.CrmSdk.CoreAssemblies NuGet package, you don't need to create a package.

Learn how create and register a plug-in package using PAC CLI and how to create and register a plug-in package using Visual Studio.

All projects must be in the SDK style

A plug-in package must only contain custom assemblies that are built from a project file in a specific format known as the SDK style. Failure to follow this rule results in an error ("file can not be found") when attempting to register the package using the Plug-in Registration tool.


All MSBuild projects, where the resulting compiled assembly is to be added to a plug-in package, must be in the "SDK style" format.

An SDK style project is one where the contents of the project's .csproj file contains the following line of code: <Project Sdk="Microsoft.NET.Sdk">.

When you create a plug-in project using one of our tools, for example the Power Platform CLI pac plugin init command, the plug-in project file is in the correct format. Here's an example of such a project file.

<Project Sdk="Microsoft.NET.Sdk">


If you're adding another project to the Visual Studio solution, say a class library project, you can create an SDK style project by following these steps.

  1. In Visual Studio, add the new project to your solution using a .NET or .NET Standard template. Do not target .NET Framework.
  2. Edit the project file by right-clicking on the project name in Solution Explorer and select Edit project file, or simply open the project's .csproj file in a separate editor.
  3. You should see the line <Project Sdk="Microsoft.NET.Sdk"> in the project file. Change the TargetFramework property to be <TargetFramework>net462</TargetFramework> and save the file.
  4. Verify your solution builds, and you're done.

More information: .NET Project SDKs

Don't depend on System.Text.Json

Because the Microsoft.CrmSdk.CoreAssemblies NuGet package has a dependency on System.Text.Json, you're able to refer to System.Text.Json types at design time. However, the System.Text.Json.dll file in the sandbox runtime might not be the same version that you refer to in your project. If you need to use System.Text.Json, you should use the dependent assembly capability and explicitly include it in your NuGet package.

Next step

See also