MCPInvoke is a custom MCP execution endpoint, designed as a companion to the MCPBuckle library (which handles MCP discovery). MCPInvoke manages the execution of tools defined by MCP requests.
This library enables ASP.NET Core applications with existing REST APIs and Swagger/OpenAPI documentation to easily become MCP-enabled. It provides a standardized execution endpoint for tools discovered via MCPBuckle.
- Attribute-Driven (Optional, Extensible) - Leverages existing OpenAPI/Swagger metadata by default, with optional MCP-specific attributes for customization
- Standard-Compliant - Implements JSON-RPC 2.0 and MCP specifications
- Developer-Friendly - Minimal friction for projects already using Swagger/OpenAPI
- Secure - Input validation, sanitized outputs, and support for human-in-the-loop confirmations
- Enhanced API Response Handling - Improved handling of complex ASP.NET Core return types including ActionResult, ObjectResult, and other IActionResult implementations
- MCPBuckle 1.5.0 Integration - Updated to use MCPBuckle 1.5.0 with enhanced schema generation, better parameter binding, and improved enum support
- Advanced Enum Support - Added full support for enum types, including both integer and string-based enums with JsonStringEnumConverter compatibility
- Collection Type Support - Better handling of array and collection return types for improved client compatibility
- New Middleware Architecture - Introduced dedicated McpInvokeMiddleware for more efficient request processing
- Simplified Configuration - Added ApplicationBuilderExtensions with UseMcpInvoke extension method for easier integration
- Parameter Annotations - Added support for additional parameter metadata through Annotations property
- MCPBuckle 1.4.0 Integration - Updated to use the MCPBuckle 1.4.0 NuGet package for better MCP specification compliance
- Special JSON-RPC Method Handling - Added support for standard JSON-RPC methods:
notifications/initialized- Properly acknowledges initialization notifications from MCP clientstools/list- Returns a helpful error message directing clients to use the MCP context endpoint instead
dotnet add package MCPInvoke// In Program.cs or Startup.cs
using MCPInvoke.Extensions;
using MCPInvoke.AspNetCore.Extensions;
// Register MCPInvoke services
builder.Services.AddMcpInvoke();
// Register an implementation of IMcpToolDefinitionProvider
// See below for ASP.NET Core controller integration
// Register endpoint using the middleware
app.UseMcpInvoke("/mcpinvoke");MCPInvoke provides automatic ASP.NET Core controller integration:
// In Program.cs or Startup.cs
using MCPInvoke.AspNetCore.Extensions;
// Register MCPInvoke with ASP.NET Core controller integration
builder.Services.AddMcpInvokeWithControllers(options => {
// Include controller name in tool name
options.IncludeControllerNameInToolName = true;
// Optionally exclude specific controllers
// options.ExcludedControllers.Add("Health");
});
// Use the MCP Invoke middleware
app.UseMcpInvoke("/mcpinvoke");For more detailed information on ASP.NET Core integration, see the AspNetCore README.