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docs/en/Community-Articles/2022-09-18-Grpc-Demo-Part-2/POST.md

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-# Consuming gRPC Services from Blazor Client Using gRPC-Web
+# Consuming gRPC Services from Blazor WebAssembly Application Using gRPC-Web
 
-TODO
+> **WARNING: I've demonstrated [Using gRPC with the ABP Framework](https://community.abp.io/posts/using-grpc-with-the-abp-framework-2dgaxzw3) in my latest post. If you haven't seen it, you should read it before this article, since this is a continuation of that article.**
+
+In this second part, I will show how to consume the gRPC service from the Blazor WebAssembly application, using the gRPC-Web technology.
+
+This will be a short article, based on Microsoft's [gRPC-Web in ASP.NET Core gRPC apps](https://learn.microsoft.com/en-us/aspnet/core/grpc/grpcweb) and [Code-first gRPC services and clients with .NET](https://learn.microsoft.com/en-us/aspnet/core/grpc/code-first) documents. For more information, I suggest to check these documents. Let's get start...
+
+## Configuring the Server Side
+
+First of all, the server-side should support gRPC-Web. Follow the steps below to enable it:
+
+### Add Grpc.AspNetCore.Web Package
+
+Add [Grpc.AspNetCore.Web](https://www.nuget.org/packages/Grpc.AspNetCore.Web) NuGet package to the `ProductManagement.HttpApi.Host` project.
+
+### Add GrpcWeb Middleware
+
+Add the following line just before the `app.UseConfiguredEndpoints(...)` line to add the GrpcWeb middleware to your ASP.NET Core request pipeline:
+
+````csharp
+app.UseGrpcWeb(new GrpcWebOptions { DefaultEnabled = true });
+````
+
+### Configure Cors
+
+ABP's startup template already configures Cors when you create a new solution. However, we need to allow some extra headers in our Cors configuration.
+
+Add the following line just after the `.WithAbpExposedHeaders()` line in the `OnApplicationInitialization` method of the `ProductManagementHttpApiHostModule` class:
+
+````csharp
+.WithExposedHeaders("Grpc-Status", "Grpc-Message", "Grpc-Encoding", "Grpc-Accept-Encoding")
+````
+
+Finally, call `RequireCors` extension method just after the `MapGrpcService` calls:
+
+````csharp
+app.UseConfiguredEndpoints(endpoints =>
+{
+    endpoints
+        .MapGrpcService<IProductAppService>()
+        .RequireCors("__DefaultCorsPolicy"); // Configure Cors for the product service
+});
+````
+
+`__DefaultCorsPolicy` may seem a magic string here. Let me explain it: ABP startup template configures the default Cors policy with the `context.Services.AddCors(...)` method (you can see it in the source code). If we define a named policy, we should use the same name here. However, when we don't specify, ASP.NET Core uses `__DefaultCorsPolicy` as the policy name by default. If you don't want to use the magic string, you can resolve the `IOptions<CorsOptions>` service and get the `DefaultPolicyName` from the `CorsOption` object.
+
+Anyway, that's all on the server-side. We can work on he client now.
+
+## Configuring the Client Side
+
+`ProductManagement.Blazor` is the Blazor WebAssembly application in the solution I'd created in the [first article](https://community.abp.io/posts/using-grpc-with-the-abp-framework-2dgaxzw3). We will configure that project to be able to consume the server-side gRPC services from our Blazor application.
+
+### Add Client-side Nuget Packages
+
+Add [Grpc.Net.Client](https://www.nuget.org/packages/Grpc.Net.Client), [Grpc.Net.Client.Web](https://www.nuget.org/packages/Grpc.Net.Client.Web) and [protobuf-net.Grpc](https://www.nuget.org/packages/protobuf-net.Grpc) NuGet packages to the `ProductManagement.Blazor` project.