title	author	description	monikerRange	ms.author	ms.date	uid
Create a .NET gRPC client and server in ASP.NET Core	jamesnk	This tutorial shows how to create a gRPC Service and gRPC client on ASP.NET Core. Learn how to create a gRPC Service project, edit a proto file, and add a duplex streaming call.	>= aspnetcore-3.0	wpickett	01/30/2025	tutorials/grpc/grpc-start

Tutorial: Create a gRPC client and server in ASP.NET Core

:::moniker range=">= aspnetcore-9.0" This tutorial shows how to create a .NET gRPC client and an ASP.NET Core gRPC Server. At the end, you'll have a gRPC client that communicates with the gRPC Greeter service.

In this tutorial, you:

[!div class="checklist"]

Create a gRPC Server.

Create a gRPC client.

Test the gRPC client with the gRPC Greeter service.

Prerequisites

Visual Studio

[!INCLUDE]

Visual Studio Code

[!INCLUDE]

Create a gRPC service

Visual Studio

Start Visual Studio 2022 and select New Project.
In the Create a new project dialog, search for gRPC. Select ASP.NET Core gRPC Service and select Next.
In the Configure your new project dialog, enter GrpcGreeter for Project name. It's important to name the project GrpcGreeter so the namespaces match when you copy and paste code.
Select Next.
In the Additional information dialog, select .NET 9.0 (Standard Term Support) and then select Create.

Visual Studio Code

The tutorial assumes familiarity with VS Code. For more information, see Getting started with VS Code.

Select New Terminal from the Terminal menu to open the integrated terminal.
Change to the directory (cd) that will contain the project.
Run the following commands:
```
dotnet new grpc -o GrpcGreeter
code -r GrpcGreeter
```
The dotnet new command creates a new gRPC service in the GrpcGreeter folder.

The code command opens the GrpcGreeter project folder in the current instance of Visual Studio Code.

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Run the service

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The logs show the service listening on https://localhost:<port>, where <port> is the localhost port number randomly assigned when the project is created and set in Properties/launchSettings.json.

info: Microsoft.Hosting.Lifetime[0]
      Now listening on: https://localhost:<port>
info: Microsoft.Hosting.Lifetime[0]
      Application started. Press Ctrl+C to shut down.
info: Microsoft.Hosting.Lifetime[0]
      Hosting environment: Development

Note

The gRPC template is configured to use Transport Layer Security (TLS). gRPC clients need to use HTTPS to call the server. The gRPC service localhost port number is randomly assigned when the project is created and set in the Properties\launchSettings.json file of the gRPC service project.

Examine the project files

GrpcGreeter project files:

Protos/greet.proto: defines the Greeter gRPC and is used to generate the gRPC server assets. For more information, see Introduction to gRPC.
Services folder: Contains the implementation of the Greeter service.
appSettings.json: Contains configuration data such as the protocol used by Kestrel. For more information, see xref:fundamentals/configuration/index.
Program.cs, which contains:
- The entry point for the gRPC service. For more information, see xref:fundamentals/host/generic-host.
- Code that configures app behavior. For more information, see App startup.

Create the gRPC client in a .NET console app

Visual Studio

Open a second instance of Visual Studio and select New Project.
In the Create a new project dialog, select Console App, and select Next.
In the Project name text box, enter GrpcGreeterClient and select Next.
In the Additional information dialog, select .NET 9.0 (Standard Term Support) and then select Create.

Visual Studio Code

Open the integrated terminal.
Change directories (cd) to a folder for the project.

Run the following commands:

dotnet new console -o GrpcGreeterClient
code -r GrpcGreeterClient

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Add required NuGet packages

The gRPC client project requires the following NuGet packages:

Grpc.Net.Client, which contains the .NET client.
Google.Protobuf, which contains protobuf message APIs for C#.
Grpc.Tools, which contain C# tooling support for protobuf files. The tooling package isn't required at runtime, so the dependency is marked with PrivateAssets="All".

Visual Studio

Install the packages using either the Package Manager Console (PMC) or Manage NuGet Packages.

PMC option to install packages

From Visual Studio, select Tools > NuGet Package Manager > Package Manager Console
From the Package Manager Console window, run cd GrpcGreeterClient to change directories to the folder containing the GrpcGreeterClient.csproj files.

Run the following commands:

Install-Package Grpc.Net.Client
Install-Package Google.Protobuf
Install-Package Grpc.Tools

Manage NuGet Packages option to install packages

Right-click the project in Solution Explorer > Manage NuGet Packages.
Select the Browse tab.
Enter Grpc.Net.Client in the search box.
Select the Grpc.Net.Client package from the Browse tab and select Install.
Repeat for Google.Protobuf and Grpc.Tools.

Visual Studio Code

Run the following commands from the Integrated Terminal:

dotnet add GrpcGreeterClient.csproj package Grpc.Net.Client
dotnet add GrpcGreeterClient.csproj package Google.Protobuf
dotnet add GrpcGreeterClient.csproj package Grpc.Tools

Add greet.proto

Create a Protos folder in the gRPC client project.
Copy the Protos\greet.proto file from the gRPC Greeter service to the Protos folder in the gRPC client project.
Update the namespace inside the greet.proto file to the project's namespace:
```
option csharp_namespace = "GrpcGreeterClient";
```
Edit the GrpcGreeterClient.csproj project file:

Visual Studio

Right-click the project and select Edit Project File.

Visual Studio Code

Select the GrpcGreeterClient.csproj file.

Add an item group with a <Protobuf> element that refers to the greet.proto file:

<ItemGroup>
  <Protobuf Include="Protos\greet.proto" GrpcServices="Client" />
</ItemGroup>

Create the Greeter client

Build the client project to create the types in the GrpcGreeterClient namespace.

Note

The GrpcGreeterClient types are generated automatically by the build process. The tooling package Grpc.Tools generates the following files based on the greet.proto file:

GrpcGreeterClient\obj\Debug\[TARGET_FRAMEWORK]\Protos\Greet.cs: The protocol buffer code which populates, serializes and retrieves the request and response message types.
GrpcGreeterClient\obj\Debug\[TARGET_FRAMEWORK]\Protos\GreetGrpc.cs: Contains the generated client classes.

For more information on the C# assets automatically generated by Grpc.Tools, see gRPC services with C#: Generated C# assets.

Update the gRPC client Program.cs file with the following code.

[!code-csharp]
In the preceding highlighted code, replace the localhost port number 7042 with the HTTPS port number specified in Properties/launchSettings.json within the GrpcGreeter service project.

Program.cs contains the entry point and logic for the gRPC client.

The Greeter client is created by:

Instantiating a GrpcChannel containing the information for creating the connection to the gRPC service.
Using the GrpcChannel to construct the Greeter client:

[!code-csharp]

The Greeter client calls the asynchronous SayHello method. The result of the SayHello call is displayed:

[!code-csharp]

Test the gRPC client with the gRPC Greeter service

Update the appsettings.Development.json file by adding the following highlighted lines:

[!code-csharp]

Visual Studio

In the GrpcGreeter service project, press Ctrl+F5 to start the server without the debugger.
In the GrpcGreeterClient console project, press Ctrl+F5 to start the client without the debugger.

Visual Studio Code

Start the Greeter service.
Start the client.

The client sends a greeting to the service with a message containing its name, GreeterClient. The service sends the message "Hello GreeterClient" as a response. The "Hello GreeterClient" response is displayed in the command prompt:

Greeting: Hello GreeterClient
Press any key to exit...

The gRPC service records the details of the successful call in the logs written to the command prompt:

info: Microsoft.Hosting.Lifetime[0]
      Now listening on: https://localhost:<port>
info: Microsoft.Hosting.Lifetime[0]
      Application started. Press Ctrl+C to shut down.
info: Microsoft.Hosting.Lifetime[0]
      Hosting environment: Development
info: Microsoft.Hosting.Lifetime[0]
      Content root path: C:\GH\aspnet\docs\4\Docs\aspnetcore\tutorials\grpc\grpc-start\sample\GrpcGreeter
info: Microsoft.AspNetCore.Hosting.Diagnostics[1]
      Request starting HTTP/2 POST https://localhost:<port>/greet.Greeter/SayHello application/grpc
info: Microsoft.AspNetCore.Routing.EndpointMiddleware[0]
      Executing endpoint 'gRPC - /greet.Greeter/SayHello'
info: Microsoft.AspNetCore.Routing.EndpointMiddleware[1]
      Executed endpoint 'gRPC - /greet.Greeter/SayHello'
info: Microsoft.AspNetCore.Hosting.Diagnostics[2]
      Request finished HTTP/2 POST https://localhost:7042/greet.Greeter/SayHello - 200 - application/grpc 40.4615ms

Note

The code in this article requires the ASP.NET Core HTTPS development certificate to secure the gRPC service. If the .NET gRPC client fails with the message The remote certificate is invalid according to the validation procedure. or The SSL connection could not be established., the development certificate isn't trusted. To fix this issue, see Call a gRPC service with an untrusted/invalid certificate.

Next steps

View or download the completed sample code for this tutorial (how to download).
xref:grpc/index
xref:grpc/basics
xref:grpc/migration

:::moniker-end

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