anthony-c-martin/remote-mcp-dotnet-oauth

Model Context Protocol (MCP) Server - .NET Implementation

This project contains a .NET web app implementation of a Model Context Protocol (MCP) server. The application is designed to be deployed to Azure App Service.

This project uses OAuth OBO, which allows users to authenticate via MCP, and then gives the MCP the ability to access downstream APIs on behalf of the user. In this example, it has been given access to Azure Resource Manager APIs.

The MCP server provides an API that follows the Model Context Protocol specification, allowing AI models to request additional context during inference.

Key Features

• Complete implementation of the MCP protocol in C#/.NET using MCP csharp-sdk
• Azure App Service integration
• Custom tools support
• Support for OAUth OBO, giving the server the ability to access authenticated downstream APIs in the user's context.

Project Structure

• src/ - Contains the main C# project files
  • Program.cs - The entry point for the MCP server
  • Tools/ - Contains custom tools that can be used by models via the MCP protocol
    • AzureResourceManagerTools.cs - Tools for performing basic Azure Resource Manager operations
• infra/ - Contains Azure infrastructure as code using Bicep
  • main.bicep - Main infrastructure definition
  • resources.bicep - Resource definitions
  • main.bicepparam - Parameters for deployment

Prerequisites

• Azure Developer CLI
• .NET 9 SDK
• For local development with VS Code:
  • Visual Studio Code

Local Development

Run the Server Locally

1. Clone this repository
2. Navigate to the project directory

   cd src
   

3. Install required packages

   dotnet restore
   

4. Run the project:

   dotnet run
   

5. The MCP server will be available at http://localhost:5000
6. When you're done, press Ctrl+C in the terminal to stop the app

Testing the Available Tools

The server provides these tools:

• AzureResourceManager:
  • get_subscriptions - Get a list of Azure subscriptions
  • get_resource_groups - Get a list of Azure resource groups in a particular Azure subscription

Connect to the Local MCP Server

Using VS Code - Copilot Agent Mode

1. Add MCP Server from command palette and add the URL to your running server's HTTP endpoint:

   http://localhost:5000
   

2. List MCP Servers from command palette and start the server
3. In Copilot chat agent mode, enter a prompt to trigger the tool:

   Fetch my Azure subscriptions
   

4. When prompted to run the tool, consent by clicking Continue

Using MCP Inspector

1. In a new terminal window, install and run MCP Inspector:

   npx @modelcontextprotocol/inspector
   

2. CTRL+click the URL displayed by the app (e.g. http://localhost:5173/#resources)
3. Set the transport type to HTTP
4. Set the URL to your running server's HTTP endpoint and Connect:

   http://localhost:5000
   

5. List Tools, click on a tool, and Run Tool

Deploy to Azure

1. Login to Azure:

   azd auth login
   

2. Initialize your environment:

   azd env new
   

3. Deploy the application:

   azd up
   

4. Grant admin consent (Entra Portal UI) - first time only:

   • Open the Entra application in App Registrations
   • Select "Manage" -> "API Permissions", and press "Grant admin consent"

   This will:

   • Build the .NET application
   • Provision Azure resources defined in the Bicep templates
   • Deploy the application to Azure App Service

Connect to Remote MCP Server

Using MCP Inspector

Use the web app's URL:

https://<webappname>.azurewebsites.net

Using VS Code - GitHub Copilot

Follow the same process as with the local app, but use your App Service URL:

https://<webappname>.azurewebsites.net

Clean up resources

When you're done working with your app and related resources, you can use this command to delete the function app and its related resources from Azure and avoid incurring any further costs:

azd down