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# Model Context Protocol .NET Template
<p align="center">
<img src="assets/light.png" alt="MCP Logo" />
</p>
<p align="center">
<strong>A protocol for seamless integration between LLM applications and external data sources</strong>
</p>
<p align="center">
<a href="https://modelcontextprotocol.io">Documentation</a> |
<a href="https://spec.modelcontextprotocol.io">Specification</a> |
<a href="https://github.com/orgs/modelcontextprotocol/discussions">Discussions</a>
</p>
This repository contains a [template](https://www.nuget.org/packages/Nall.ModelContextProtocol.Template) for creating a Model Context Protocol (MCP) application in .NET. It provides a basic structure and example code to help you get started with building your own MCP-enabled applications.
| Package | Version | Description |
| ---------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------- |
| `Nall.ModelContextProtocol.Template` | [](https://nuget.org/packages/Nall.ModelContextProtocol.Template) | Templates |
| `Nall.ModelContextProtocol.Inspector.Aspire.Hosting` | [](https://nuget.org/packages/Nall.ModelContextProtocol.Inspector.Aspire.Hosting) | Aspire Hosting Integration |
## Getting Started
### Install:
```bash
dotnet new install Nall.ModelContextProtocol.Template
# dotnet new install ./Artefact/Nall.ModelContextProtocol.Template
```
Verify installation:
```bash
dotnet new list mcp
# These templates matched your input: 'mcp'
# Template Name Short Name Language Tags
# ----------------- ----------------- -------- -------------
# Template Name Short Name Language Tags
# -------------------- -------------------- -------- -------------
# MCP Server mcp-server [C#] dotnet/ai/mcp
# MCP Server HTTP mcp-server-http [C#] dotnet/ai/mcp
# MCP Server HTTP Auth mcp-server-http-auth [C#] dotnet/ai/mcp
# MCP Server Hybrid mcp-server-hybrid [C#] dotnet/ai/mcp
```
> [!TIP]
> Practically, you want to switch between modes, so I recommend using the `mcp-server-hybrid` template. It allows you to run the server in both *Stdio* and *HTTP* modes.
Verify output:
```bash
dotnet new mcp-server -o MyAwesomeMCPServer -n MyAwesomeMCPServer --dry-run
# File actions would have been taken:
# Create: MyAwesomeMCPServer\.vscode\launch.json
# Create: MyAwesomeMCPServer\MyAwesomeMCPServer.csproj
# Create: MyAwesomeMCPServer\Program.cs
# Create: MyAwesomeMCPServer\Properties\launchSettings.json
# Create: MyAwesomeMCPServer\README.md
# Create: MyAwesomeMCPServer\appsettings.Development.json
# Create: MyAwesomeMCPServer\appsettings.json
```
Create from template:
```bash
dotnet new mcp-server -o MyAwesomeMCPServer -n MyAwesomeMCPServer
```
Here is a content of `Program.cs`:
```csharp
using Microsoft.Extensions.Hosting;
var builder = Host.CreateApplicationBuilder(args);
builder.Services
.AddMcpServer()
.WithStdioServerTransport()
.WithToolsFromAssembly();
await builder.Build().RunAsync();
[McpServerToolType]
public static class EchoTool
{
[McpServerTool, Description("Echoes the message back to the client.")]
public static string Echo(string message) => $"hello {message}";
}
```
It is a simple echo server that listens for incoming messages and responds with a greeting. You can add more tools by creating additional methods with the `[McpServerTool]` attribute. The `WithToolsFromAssembly()` method automatically registers all tools in the assembly.
### Run Locally
Build from the project directory:
```bash
dotnet build -o Artefacts -c Release
```
Run the inspector:
```bash
npx @modelcontextprotocol/inspector -e DOTNET_ENVIRONMENT=Production dotnet "$(PWD)/Artefacts/MyAwesomeMCPServer.dll"
```
Open inspector in your browser and test the server:
<p align="center">
<img src="assets/inspector-demo.png" alt="Inspector Demo" />
</p>
### Distribute as .NET Tool
Pack from the project directory:
```bash
dotnet pack -o Artefacts -c Release
```
Install the tool globally:
```bash
dotnet tool install --global --add-source ./Artefacts MyAwesomeMCPServer
```
Now, after you installed this tool globally, you can run it from anywhere on your system. The tool will be available as `MyAwesomeMCPServer` (or `myawesomemcpserver`) in your terminal.
💡 You can also create local tool manifest and install MCPs as tools locally.
Run the inspector:
```bash
npx @modelcontextprotocol/inspector -e DOTNET_ENVIRONMENT=Production myawesomemcpserver
```
## Run with Aspire
### In `Stdio` mode
In `AppHost/Program.cs`:
```csharp
var builder = DistributedApplication.CreateBuilder(args);
builder.AddMCPInspector().WithStdio<Projects.MCPServer>();
builder.Build().Run();
```
### In `HTTP` mode
In `AppHost/Program.cs`:
```csharp
var builder = DistributedApplication.CreateBuilder(args);
var mcp = builder.AddProject<Projects.MCPServerRemote>("server");
builder.AddMCPInspector().WithMcp(mcp);
builder.Build().Run();
```
## Reference
- <https://learn.microsoft.com/en-us/dotnet/core/tools/custom-templates>
- <https://learn.microsoft.com/en-us/dotnet/core/tools/global-tools>
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