MCPfiedSwagger 🚀

An ASP.NET extension that generates a Model Context Protocol (MCP) server, enabling seamless conversion of existing REST APIs as MCP tools, now with enhanced authorization support and improved schema descriptions.

📦 Installation

Install the MCPfiedSwagger NuGet package from your preferred NuGet source:

dotnet add package MCPfiedSwagger

Or via the NuGet Package Manager:

PM> Install-Package MCPfiedSwagger

⚙️ Usage

1. Add the MCPfiedSwagger service in your ASP.NET Core project. In your Program.cs, register the service after adding controllers and Swagger:

builder.Services.AddMCPfiedSwagger();

2. Enable the middleware in your HTTP pipeline, after mapping controllers:

app.UseMCPfiedSwagger();

3. Configure Swagger (optional): By default, the Swagger/OpenAPI document is named "v1". To specify a different document name, pass it as an argument:

app.UseMCPfiedSwagger("v1");

4. Specify the MCP endpoint (optional): The default MCP endpoint is /mcp. To change it, provide the desired path:

app.UseMCPfiedSwagger("v1", "/custom-mcp-endpoint");

🔒 Authorization Support

Authorization support is now integrated. You can enable stateless authorization easily:

builder.Services.AddMCPfiedSwagger()
    .AddAuthorization();

The authorization process validates controller actions based on Authorize attributes and handles unauthorized requests gracefully.

📝 Example

A minimal Program.cs setup:

using MCPfiedSwagger.Extensions;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddControllers();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();
builder.Services.AddMCPfiedSwagger();

var app = builder.Build();

app.UseSwagger();
app.UseSwaggerUI();

app.UseAuthorization();
app.MapControllers();

// Enable MCP endpoint at /mcp for the "v1" Swagger document
app.UseMCPfiedSwagger();

app.Run();

▶️ Running the Example Project

With Authentication Example

1. Restore dependencies and build:

dotnet restore
dotnet build

2. Run the authentication example project:

dotnet run --project MCPfiedSwagger.Authenticated

3. Access the Swagger UI: Open 🌐 http://localhost:<port>/swagger in your browser.

4. Test Authorization:

   • Authenticate via POST /api/Auth/login with username test and password password.
   • Use the received JWT token as your authorization header when connecting to your MCP endpoint.

Standard Example

Run the original example project:

dotnet run --project MCPfiedSwagger.Example

• Swagger UI: 🌐 http://localhost:<port>/swagger
• MCP Endpoint: 🔗 http://localhost:<port>/mcp

💡 Notes

• The NuGet package depends on ModelContextProtocol.AspNetCore and Swashbuckle.AspNetCore.
• Ensure your project targets .NET 9.0 or compatible.
• For more details, see the project repository.
• Streamable HTTP MCP does not work on https for some reason. Still trying to investigate the issue I encountered.